CN116243850B - Memory management method and electronic equipment - Google Patents

Abstract

The present application provides a memory management method and electronic device, which relates to the field of computer technology, and solves the problem that when a user opens many applications, the data swapped out by the electronic device gradually increases, and the compressed data will occupy a large amount of storage space, resulting in less remaining storage space in the RAM. The method includes: when the available storage space of the first memory is less than a first threshold, the electronic device compresses the first data in the data and stores it in the first memory; the electronic device releases the storage space occupied by the first data before compression; when the storage space occupied by the compressed data in the first memory is greater than a second threshold, the electronic device stores the second data in the second memory, the second data is the data whose compression rate meets the threshold condition in the compressed data in the first memory, and the compressed data in the first memory includes the first data; the electronic device releases the storage space occupied by the second data.

Description

Memory management method and electronic device

This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on June 8, 2021, with application number 202110640318.6 and application name “A Memory Management Method and Electronic Device”, all contents of which are incorporated by reference in this application.

This application is a divisional application. The application number of the original application is 202110751464.6, and the original application date is July 2, 2021. The entire contents of the original application are incorporated into this application by reference.

Technical Field

The present application relates to the field of computer technology, and in particular to a memory management method and an electronic device.

Background technique

At present, users can install application programs (hereinafter referred to as applications) in electronic devices such as mobile phones to enrich their functions. For example, a video application is installed in a mobile phone. After receiving the user's operation to open the video application, the mobile phone can display the interface of the video application in the foreground for the user to use its corresponding functions, such as watching videos. Afterwards, when the user needs to switch to other applications or desktops, the video application can be switched to the background by performing corresponding operations. Generally, when the application is turned on, the electronic device can allocate storage space for storing relevant data of the application. When the application is switched to the background, it will continue to occupy the storage space for storing relevant data, such as the data of the last displayed interface before switching to the background, so that when the user switches the application to the foreground, the interface can be displayed in time for the user to view. If the user opens multiple applications and does not close them after use (such as switching to the background), the mobile phone will save the relevant data of each application opened by the user, resulting in a large amount of storage space in the random access memory (RAM) being occupied by the background running applications, thereby making the available storage space of the RAM low.

Summary of the invention

The present application provides a memory management method and electronic device, which solves the problem that when a user opens many applications, the data swapped out by the electronic device gradually increases, and the compressed data takes up a large amount of storage space, resulting in less remaining storage space in the RAM.

In order to achieve the above objectives, this application adopts the following technical solutions:

In a first aspect, an embodiment of the present application provides a memory management method, which is applied to an electronic device, wherein the electronic device includes a first memory and a second memory, and the first memory stores data of an application running in the background; the method includes: when the available storage space of the first memory is less than a first threshold, the electronic device compresses the first data in the data and stores it in the first memory; the electronic device releases the storage space occupied by the first data before compression; when the storage space occupied by the compressed data in the first memory is greater than a second threshold, the electronic device stores the second data in the second memory, the second data being the data in the compressed data in the first memory whose compression rate meets the threshold condition, and the compressed data in the first memory includes the first data; the electronic device releases the storage space occupied by the second data.

In the above embodiment, when the available storage space of the first memory is less than the first threshold, the electronic device compresses the first data in the data and stores it in the first memory, and releases the storage space occupied by the first data before compression. Since the storage space occupied by the compressed data is less than the storage space occupied by the data before compression, more storage space can be released. Afterwards, when the storage space occupied by the compressed data in the first memory is greater than the second threshold, it means that there are too many compressed first cold data stored in the first memory at this time, resulting in a small available storage space in the first memory. To this end, the memory management method provided by the embodiment of the present application is to store the data whose compression rate meets the threshold condition in the compressed data in the first memory in the second memory. Thereby, the first data stored in the first memory is smaller, and the electronic device releases the storage space occupied by the second data, so that the available storage space of the first memory is larger. It solves the problem that when the user opens more applications, the data swapped out by the electronic device 100 gradually increases, and the compressed data will occupy a large amount of storage space, resulting in less remaining storage space in the RAM.

In combination with the first aspect, in a possible implementation, the electronic device compresses the first data in the data and stores it in the first memory, including: the electronic device compresses the first data; the electronic device stores the compressed first data in the form of an exchange unit in the first memory; wherein the compression rate difference of the compressed first data in the same exchange unit is less than a third threshold.

In the above embodiment, by storing the first data whose compression ratio difference is less than the third threshold value in the same exchange unit, the first data can be managed more conveniently. At the same time, when the exchange units are of the same size, the higher the compression ratio of the corresponding first data, the less the first data stored in the exchange unit, so the probability of the exchange unit being swapped in is lower, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the electronic device stores the second data in a second memory, including: the electronic device determines that all compressed first data in an exchange unit whose compression rate is greater than a fourth threshold is the second data; the electronic device stores the second data in the second memory; wherein the compression rate of each exchange unit is determined based on the compression rate of the compressed first data in the exchange unit.

In the above embodiment, the compression rate of the exchange unit is determined according to the compression rate of the first data compressed in the exchange unit. Thus, when the exchange units are of the same size, the greater the compression rate corresponding to the exchange unit, the less the first data stored in the exchange unit, and thus the lower the probability of swapping in the exchange unit, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the electronic device stores the second data in a second memory, including: the electronic device determines that all compressed first data in the switching units whose compression rate is greater than a fourth threshold and whose swap-in probability is less than a fifth threshold are second data; the electronic device stores the second data in the second memory; wherein the compression rate of each switching unit is determined based on the compression rate of the compressed first data in the switching unit, and the swap-in probability of each switching unit is determined based on the probability of the compressed first data in the switching unit being accessed.

In the above embodiment, the compression rate of each exchange unit is determined according to the compression rate of the first data compressed in the exchange unit, and the swap-in probability of each exchange unit is determined according to the probability of the first data compressed in the exchange unit being accessed. In this way, when the exchange units are of the same size, the larger the compression rate corresponding to the exchange unit, the less the first data stored in the exchange unit, and thus the lower the swap-in probability of the exchange unit, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the electronic device stores the second data in a second memory, including: the electronic device determines, based on the compression rate of each exchange unit, that the second data is the first data compressed in the exchange unit in order from large to small; the electronic device stores the second data in the second memory in sequence until the available storage space of the first memory is greater than a first threshold.

In the above embodiment, the exchange units are stored in the second memory in descending order according to the compression rate corresponding to each exchange unit, until the available storage space of the first memory is greater than the first threshold. In this way. When the exchange units are of the same size, the higher the compression rate of the corresponding first data, the less the first data stored in the exchange unit, so that the probability of the exchange unit being swapped in is lower, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the first memory is a memory, and the second memory is an external memory.

In combination with the first aspect, in a possible implementation, an electronic device includes a ZRAM block device, a zspage module, a swap block device and a memory management module, and the method includes: when the available storage space of the first memory is less than a first threshold, the memory management module stores the first data in the data in the swap space (Swap space) set in the first memory through the ZRAM block device; the ZRAM block device compresses the first data in the Swap space and sends the compressed first data to the zspage module; the zspage module stores the compressed first data in the first memory; the memory management module releases the storage space occupied by the first data before compression; when the storage space occupied by the compressed data in the first memory by the ZRAM block device is greater than a second threshold, the Swap block device is notified through an interface; the Swap block device obtains the second data from the zspage module through the interface; the zspage module determines that the second data is the data whose compression rate meets the threshold condition in the compressed data in the first memory; the zspage module sends the second data to the Swap block device; the Swap block device stores the second data in the second memory, and the compressed data in the first memory includes the first data; the memory management module releases the storage space occupied by the second data.

In the above embodiment, when the available storage space of the first memory is less than the first threshold, the memory management module stores the first data in the data to the Swap space set in the first memory through the ZRAM block device; the ZRAM block device compresses the first data in the Swap space and sends the compressed first data to the zspage module; the zspage module stores the compressed first data in the first memory; the memory management module releases the storage space occupied by the first data before compression. Since the storage space occupied by the compressed data is less than the storage space occupied by the data before compression, more storage space can be released. Afterwards, when the storage space occupied by the compressed data in the first memory by the ZRAM block device is greater than the second threshold, it means that there are too many compressed first cold data stored in the first memory at this time, resulting in a small available storage space in the first memory. To this end, the memory management method provided in the embodiment of the present application is as follows: the ZRAM block device notifies the Swap block device through an interface; the Swap block device obtains the second data from the zspage module through the interface; the zspage module determines that the second data is data whose compression rate meets the threshold condition in the compressed data in the first memory; the zspage module sends the second data to the Swap block device; the Swap block device stores the second data in the second memory, and the compressed data in the first memory includes the first data; the memory management module releases the storage space occupied by the second data, so that the first data stored in the first memory is smaller, and at the same time the electronic device releases the storage space occupied by the second data, so that the available storage space of the first memory is larger.

In combination with the first aspect, in a possible implementation, the zspage module stores the compressed first data in the first memory, including: the zspage module stores the compressed first data in the first memory in the form of an exchange unit; wherein the compression rate difference of the compressed first data in the same exchange unit is less than a third threshold.

In the above embodiment, the zspage module stores the first data whose compression ratio difference is less than the third threshold value in the same exchange unit, so that the first data can be managed more conveniently. At the same time, when the exchange units are of the same size, the higher the compression ratio of the corresponding first data, the less the first data stored in the exchange unit, so that the probability of swapping in the exchange unit is lower, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the zspage module determines that the second data is data in the compressed data in the first memory whose compression rate meets the threshold condition, including: the zspage module determines that the second data is all compressed first data in the exchange unit whose compression rate is greater than a fourth threshold; wherein the compression rate of each exchange unit is determined based on the compression rate of the compressed first data in the exchange unit.

In the above embodiment, the compression rate zspage module of each exchange unit is determined according to the compression rate of the first data compressed in the exchange unit, and the swap-in probability of each exchange unit is determined according to the probability of the first data compressed in the exchange unit being accessed. In this way, when the exchange units are of the same size, the larger the compression rate corresponding to the exchange unit, the less the first data stored in the exchange unit, and thus the lower the swap-in probability of the exchange unit, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the zspage module determines that the second data is data in the compressed data in the first memory whose compression rate meets the threshold condition, including: the zspage module determines that the second data is all compressed first data in the exchange unit whose compression rate is greater than a fourth threshold and whose swap-in probability is less than a fifth threshold; wherein the compression rate of each exchange unit is determined based on the compression rate of the compressed first data in the exchange unit, and the swap-in probability of each exchange unit is determined based on the probability of the compressed first data in the exchange unit being accessed.

In the above embodiment, the compression rate of each exchange unit is determined according to the compression rate of the first data compressed in the exchange unit, and the swap-in probability of each exchange unit is determined according to the probability of the first data compressed in the exchange unit being accessed. In this way, when the exchange units are of the same size, the larger the compression rate corresponding to the exchange unit, the less the first data stored in the exchange unit, and thus the lower the swap-in probability of the exchange unit, thereby reducing the problem of data jitter caused by swapping in and out.

In combination with the first aspect, in a possible implementation, the zspage module determines that the second data is data whose compression rate satisfies a threshold condition in the compressed data in the first memory, including: the zspage module determines, based on the compression rate of each exchange unit, that the second data is the first data compressed in the exchange unit in order from large to small; the Swap block device stores the second data in the second memory, including: the Swap block device stores the second data obtained from the zspage module in the second memory in turn until the available storage space of the first memory is greater than the first threshold.

In the above embodiment, the exchange units are stored in the second memory in descending order according to the compression rate corresponding to each exchange unit, until the available storage space of the first memory is greater than the first threshold. In this way. When the exchange units are of the same size, the higher the compression rate of the corresponding first data, the less the first data stored in the exchange unit, so that the probability of the exchange unit being swapped in is lower, thereby reducing the problem of data jitter caused by swapping in and out.

In a second aspect, an embodiment of the present application provides an electronic device, including a processing unit.

The processing unit is used to compress the first data in the data and store it in the first memory when the available storage space of the first memory is less than the first threshold. The processing unit is also used to release the storage space occupied by the first data before compression. The processing unit is also used to store the second data in the second memory when the storage space occupied by the compressed data in the first memory is greater than the second threshold, the second data being the data whose compression rate meets the threshold condition among the compressed data in the first memory, and the compressed data in the first memory includes the first data. The processing unit is also used to release the storage space occupied by the second data.

In conjunction with the second aspect, in a possible implementation, the processing unit is specifically configured to compress the first data; and the processing unit is specifically configured to store the compressed first data in the first memory in the form of an exchange unit. The difference in compression rate of the compressed first data in the same exchange unit is less than a third threshold.

In conjunction with the second aspect, in a possible implementation, the processing unit is specifically configured to determine that all compressed first data in the switching unit whose compression rate is greater than a fourth threshold value is the second data. The processing unit is specifically configured to store the second data in the second memory. The compression rate of each switching unit is determined according to the compression rate of the compressed first data in the switching unit.

In conjunction with the second aspect, in a possible implementation, the processing unit is specifically configured to determine that all compressed first data in the switching unit whose compression rate is greater than a fourth threshold value and whose swap-in probability is less than a fifth threshold value is the second data. The processing unit is specifically configured to store the second data in the second memory. The compression rate of each switching unit is determined based on the compression rate of the compressed first data in the switching unit, and the swap-in probability of each switching unit is determined based on the probability of the compressed first data in the switching unit being accessed.

In combination with the second aspect, in one possible implementation, the processing unit is specifically used to determine, based on the compression rate of each exchange unit, that the second data is the first data compressed in the exchange unit in order from large to small; the processing unit is specifically used to store the second data in the second memory in sequence until the available storage space of the first memory is greater than the first threshold.

In conjunction with the second aspect, in a possible implementation, the first memory is a memory, and the second memory is an external memory.

In a third aspect, an embodiment of the present application provides an electronic device, including a ZRAM block device, a zspage module, a Swap block device, a memory management module, a first memory and a second memory. A memory management module is used to store the first data in the data to the Swap space set in the first memory through a ZRAM block device when the available storage space of the first memory is less than a first threshold value; the ZRAM block device is used to compress the first data in the Swap space and send the compressed first data to the zspage module; the zspage module is used to store the compressed first data in the first memory; the memory management module releases the storage space occupied by the first data before compression; the ZRAM block device is also used to notify the Swap block device through an interface when the storage space occupied by the compressed data in the first memory is greater than a second threshold value; the Swap block device is also used to obtain the second data from the zspage module through the interface; the zspage module is also used to determine that the second data is the data whose compression rate meets the threshold condition in the compressed data in the first memory; the zspage module is also used to send the second data to the Swap block device; the Swap block device is also used to store the second data in the second memory, and the compressed data in the first memory includes the first data; the memory management module releases the storage space occupied by the second data.

In combination with the third aspect, in a possible implementation, the zspage module is specifically used to store the compressed first data in the form of an exchange unit in the first memory; wherein the compression rate difference of the compressed first data in the same exchange unit is less than a third threshold.

In combination with the third aspect, in one possible implementation, the zspage module is specifically used to determine that the second data is all compressed first data in the exchange unit whose compression rate is greater than a fourth threshold; wherein the compression rate of each exchange unit is determined based on the compression rate of the compressed first data in the exchange unit.

In combination with the third aspect, in one possible implementation, the zspage module is specifically used to determine that the second data is all compressed first data in the exchange unit whose compression rate is greater than a fourth threshold and whose swap-in probability is less than a fifth threshold; wherein the compression rate of each exchange unit is determined based on the compression rate of the compressed first data in the exchange unit, and the swap-in probability of each exchange unit is determined based on the probability of the compressed first data in the exchange unit being accessed.

In combination with the third aspect, in a possible implementation, the zspage module is specifically used to determine, based on the compression rate of each exchange unit, that the second data is the first data compressed in the exchange unit in order from large to small; the Swap block device is specifically used to store the second data obtained from the zspage module in the second memory in sequence until the available storage space of the first memory is greater than the first threshold.

In combination with the third aspect, in a possible implementation, the first memory is a memory and the second memory is an external memory.

In a fourth aspect, an embodiment of the present application provides an electronic device, comprising: a communication interface, a processor, a memory, and a bus; the memory is used to store computer execution instructions, and the processor is connected to the memory through the bus; when the electronic device is running, the processor executes the computer execution instructions stored in the memory, so that the electronic device executes the method described in the first aspect above and any possible design method thereof.

In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium. When the instructions in the storage medium are executed by a processor of an electronic device, the electronic device can execute the method described in the first aspect above and any possible design method thereof.

In a sixth aspect, an embodiment of the present application provides a computer program product, including, when the computer program product is run on a computer, enabling the computer to execute the method described in the first aspect above and any possible design method thereof.

It can be understood that the beneficial effects that can be achieved by the electronic device described in the second aspect, the third aspect, the fourth aspect and any possible design method thereof, the computer storage medium described in the fifth aspect, and the computer program product described in the sixth aspect can be referred to the beneficial effects in the first aspect and any possible design method thereof, and will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is one of the interface schematic diagrams of a mobile phone startup display in the prior art.

FIG. 2 is a second schematic diagram of an interface displayed when a mobile phone is turned on in the prior art.

FIG. 3 is a schematic diagram of a structure of an electronic device 100 in the prior art.

FIG. 4 is a second structural schematic diagram of an electronic device 100 in the prior art.

FIG. 5 is a third structural schematic diagram of an electronic device 100 in the prior art.

FIG. 6 is a fourth structural diagram of the electronic device 100 in the prior art.

FIG. 7 is one of the structural schematic diagrams of the electronic device 200 provided in an embodiment of the present application.

FIG. 8 is a second schematic diagram of the structure of the electronic device 200 provided in an embodiment of the present application.

FIG9 is a flow chart of a memory management method provided in an embodiment of the present application.

FIG. 10 is a schematic diagram showing a comparison of data before and after compression provided in an embodiment of the present application.

FIG. 11 is a schematic diagram of data storage provided in an embodiment of the present application.

FIG. 12 is a third schematic diagram of the structure of the electronic device 200 provided in an embodiment of the present application.

FIG13 is a schematic diagram of a chip system provided in an embodiment of the present application.

Detailed ways

The following explains the relevant concepts involved in the embodiments of the present application:

Compression rate refers to the ratio of the size of data after compression to the size before compression. For example, if 100M of data is compressed and the compressed data size is 90M, the compression rate is That is, the compression rate is equal to 90%.

Cold Page can be a page relative to a hot page. A page that has been accessed within a period of time can be called a hot page. Conversely, a page that has not been accessed within a period of time is called a cold page. Hot pages can generally be stored in cache.

The LRU algorithm is a commonly used page replacement algorithm that is used to select pages that have not been accessed recently for swapping out.

In order to free up more RAM storage space for foreground running applications, the related art provides a memory optimization technology. Taking the electronic device being a mobile phone as an example, the memory optimization technology in the related art is introduced.

For example, the total storage space of a mobile phone is 100M, and the applications include application 1, application 2 and application 3. After the mobile phone is turned on, after the mobile phone receives the user's operation to start application 1, the mobile phone starts application 1, and the system of the mobile phone allocates 30M of storage space for it. Later, when the user wants to open application 2, the mobile phone receives the user's switching operation, switches application 1 to the background, and displays the desktop. At this time, the mobile phone determines that the remaining storage space of 70M is greater than the memory recovery threshold (such as 40M), and the mobile phone will not force the end of application 1. After receiving the user's operation to start application 2, the mobile phone starts application 2, and the system of the mobile phone allocates 35M of storage space for it. Later, when the user wants to open application 3, the mobile phone receives the user's switching operation, switches application 2 to the background, and displays the desktop. Because the system of the mobile phone does not kill application 1 and application 2, but continues to run application 1 and application 2 in the background, application 1 and application 2 will still occupy 65M of storage space for storing related data, such as the data of the last displayed interface before switching to the background. At this time, the mobile phone determines that the remaining storage space of 35M is less than the memory recycling threshold of 40M. The mobile phone can forcibly end the application with the earliest running time in the order of the running time of the applications. For example, the mobile phone forcibly ends application 1, thereby releasing the storage space occupied by application 1, so that when the mobile phone starts application 3, there is enough storage space allocated to application 3 to ensure the user experience.

Alternatively, after the mobile phone is turned on, after the mobile phone receives the user's operation to start application 1, the mobile phone starts application 1, and the mobile phone system allocates 30M of storage space for it. Later, when the user wants to open application 2, the mobile phone receives the user's switching operation, switches application 1 to the background, and displays the desktop. After receiving the user's operation to start application 2, the mobile phone starts application 2, and the mobile phone system allocates 35M of storage space for it. Later, when the user wants to open application 3, the mobile phone receives the user's switching operation, switches application 2 to the background, and displays the desktop. At this time, because the mobile phone system does not kill application 1 and application 2, but continues to run application 1 and application 2 in the background, application 1 and application 2 will still occupy 65M of storage space for storing related data, such as the data of the last display interface before switching to the background. After the mobile phone receives the user's operation to start application 3, before starting application 3, application 3 will apply to the mobile phone for storage space, for example, 50M of storage space. The mobile phone determines that the remaining storage space of 35M is less than the storage space of 50M required by application 3. In order to have enough storage space allocated to application 3, the mobile phone can forcibly end the application with the earliest running time in the order of the running time of the applications. For example, forcibly end application 1, thereby freeing up the storage space occupied by application 1 and providing the freed storage space to application 3.

From the above process, it can be seen that the mobile phone forcibly ends application 1, releases the corresponding storage space, and the related data stored in it will be deleted accordingly. Therefore, when application 1 is started again, the startup time required is too long. For example, when application 1 is turned on again, the startup page is displayed, and the resources required by application 1 are loaded in the process of displaying the startup page. After the required resources are loaded, the interface of application 1 will be displayed for the user to view. Alternatively, when application 1 is turned on again, application 1 may perform update detection and display an interface that is checking for updates (as shown in Figure 1). After the update check is completed, the interface of application 1 will be displayed for the user to view. Alternatively, when application 1 is turned on again, the advertising interface will be displayed first (as shown in Figure 2). After that, the interface of application 1 will be displayed for the user to view.

To solve the above problems, an implementation method is shown in Figure 3, taking the electronic device 100 including CPU, RAM and Universal Flash Storage (UFS) as an example. Among them, when the CPU determines that the remaining storage space of RAM is less than the memory recovery threshold, it determines the cold data that can be swapped out in RAM based on the Least Recently Used (LRU) algorithm, and stores the cold data in UFS. At the same time, when the cold data is accessed, the CPU needs to swap the cold data from UFS into RAM. Since UFS has a read and write rate bottleneck and a service life limit, and the cold data stored in UFS is frequently swapped out and in, this will shorten the service life of UFS and cannot be promoted on a large scale.

Another implementation is shown in FIG. 4 , where an electronic device 100 includes: a central processing unit (CPU) and a RAM as an example. Among them, a Swap space is provided on the RAM, and the RAM stores the relevant data of the application running in the background. When the remaining storage space of the RAM is less than the threshold, the CPU determines the cold data that can be swapped out from the data stored in the RAM according to the LRU algorithm. After swapping the cold data out to the Swap space, the CPU compresses the cold data in the Swap space, and stores the compressed cold data in the RAM in the form of a swap unit (such as: zspage). Since the storage space required for the compressed cold data is less than the storage space required for the cold data before compression, more storage space can be released from the internal memory. Since there is no external memory (such as UFS), the problem of not being able to be promoted on a large scale due to the bottleneck of the read and write rate and the service life limit of the external memory can be avoided. However, when the user opens more applications, the cold data swapped out by the electronic device 100 gradually increases, and the compressed cold data will occupy a large amount of storage space, resulting in less remaining storage space in the RAM.

Another implementation is shown in FIG. 5 , taking the electronic device 100 including a CPU, a RAM and a UFS as an example. Among them, a Swap space is provided on the RAM, and the RAM stores the relevant data of the application running in the background. When the CPU determines that the remaining storage space of the RAM is less than the memory recovery threshold, the CPU determines the cold data that can be swapped out in the RAM according to the LRU algorithm, and swaps the cold data out to the Swap space. The CPU compresses the cold data in the Swap space and stores the cold data in the RAM in the form of a unit (such as: zspage). When the CPU determines that the storage space occupied by the compressed cold data is greater than the threshold, the CPU determines the specified cold data that can be swapped out in the compressed cold data according to the LRU algorithm, and stores the specified cold data in the UFS. Since the compressed cold data stored in the RAM is less, more storage space can be released from the RAM. However, when the specified cold data is stored in the UFS, it is stored in the form of a swap unit (such as: zspage). When a cold page in the zspage is accessed, the CPU needs to swap all the cold pages corresponding to the cold data in the zspage into the RAM for decompression. In this case, the zspage will be frequently swapped in and out, resulting in data jitter.

Further, in one embodiment, taking the operating system of the electronic device 100 as an Android system as an example, as shown in FIG6 , the electronic device 100 can be logically divided into an application layer 11, a kernel layer 12, and a hardware layer 13. Among them, the hardware layer 13 may include the CPU, RAM, and UFS shown in FIG5 . The application layer 11 includes one or more applications (application 1 to application 3, etc.). The application can be a system application or a third-party application. The kernel layer 12 is used as a software middleware between the hardware layer 13 and the application layer 11 to manage and control hardware and software resources, for example, to manage the memory of the electronic device 100. Among them, the kernel layer 12 includes a kernel 121, a switching device 122 for providing underlying system services, and a memory management module 123 for managing memory. For example, the switching device 122 may include a ZRAM block device and a Swap block device. When the memory management module 123 determines that the RAM usage exceeds a threshold, the memory management module 123 determines the cold data according to the LRU algorithm. The memory management module 123 swaps out the cold data to the ZRAM partition in the RAM through the ZRAM block device in the switching device 122. The ZRAM block device compresses the cold data in the ZRAM partition. The ZRAM block device stores the compressed cold data in the ZRAM partition in the form of a swap unit (such as a zspage) in RAM. When the ZRAM block device determines that the total amount of compressed data exceeds the compression threshold, it notifies the Swap block device through the interface. The Swap block device obtains the specified cold data from the ZRAM block device through the interface. The ZRAM block device obtains the specified cold data from the zspage according to the LRU algorithm. The ZRAM block device sends the specified cold data to the Swap block device through the interface, and the Swap block device swaps out the specified cold data to the UFS.

In view of this, an embodiment of the present application provides a memory management method, which can be applied to an electronic device including a memory (such as a memory) to increase its available storage space. In addition, the method provided in this embodiment can also better solve the problem of jitter in and out of data stored in UFS.

The electronic device may be a mobile phone, a tablet computer, a handheld computer, a personal computer (PC), a cellular phone, a personal digital assistant (PDA), a wearable device (such as a smart watch), a smart home device (such as a TV), a car computer, a game console, and an augmented reality (AR) or virtual reality (VR) device, and the operating system of the device includes a Linux kernel layer. This embodiment does not impose any special restrictions on the specific device form of the electronic device.

The following is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. FIG7 shows a schematic diagram of the structure of an electronic device 200. The electronic device 200 may include a processor 210, an external memory interface 120, an internal memory, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a display screen 193, a subscriber identification module (SIM) card interface 194, and a camera 195, etc. Among them, the sensor module 180 may include a pressure sensor, a gyroscope sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, etc.

It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on the electronic device 100. In other embodiments of the present application, the electronic device 100 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

The processor 210 may include one or more processing units, for example: the processor 210 may include an application processor (application processor, AP), a modem processor, a graphics processor (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a memory 220, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and/or a neural-network processing unit (neural-network processing unit, NPU), etc. Among them, different processing units may be independent devices or integrated into one or more processors. Among them, the controller may be the nerve center and command center of the electronic device 100. The controller may generate an operation control signal according to the instruction opcode and the timing signal to complete the control of fetching and executing instructions. The memory 220 may be used to store computer executable program codes, such as computer programs corresponding to applications and operating systems; the processor 210 may call the computer program stored in the memory 220 to implement the functions defined by the computer program. The memory 220 may include an internal memory (also referred to as a memory) 2201 and an external memory 2202. In some embodiments of the present application, the memory 2201 is used to temporarily store the relevant data of the running application and the code and data of the operating system, and the external memory 2202 is used to store the swappable data, etc. For example, the memory 2201 can be a RAM, and the external memory 2202 can be a hard disk (HD), a solid state disk (SSD), or a UFS.

A memory may also be provided in the processor 210 for storing instructions and data. In some embodiments, the memory may be used to store computer executable program codes, such as computer programs corresponding to applications and operating systems; the processor 210 may call the computer program stored in the memory to implement the functions defined by the computer program. For example, the processor 210 may store the code corresponding to the operating system in the memory, and then execute the code corresponding to the operating system in the memory, thereby implementing various functions of the operating system on the electronic device 100. The processor 210 may also store the code corresponding to the application in the memory, and then execute the code corresponding to the application, thereby implementing various functions of the application on the electronic device 100. The operating system may be a Windows system, a MAC OS system, a Linux system, an Android system, etc., and of course it may also be a future-oriented computer system, which is not limited in the embodiments of the present application.

The external memory interface 120 may be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the electronic device 100. The internal memory may be used to store computer executable program codes, which include instructions.

The charging management module 140 is used to receive charging input from the charger. The power management module 141 is used to connect the battery 142, the charging management module 140 and the processor 210. The power management module 141 receives input from the battery 142 and/or the charging management module 140, and provides power to the processor 210, the internal memory, the external memory, the display screen 193, the camera 195, and the wireless communication module 160.

The wireless communication function of the electronic device 100 can be implemented by antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modulation and demodulation processor and baseband processor. Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. The mobile communication module 150 can provide solutions for wireless communications including 2G/3G/4G/5G applied to the electronic device 100. The wireless communication module 160 can provide solutions for wireless communications including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication technology (NFC), infrared technology (IR), etc. applied to the electronic device 100.

The audio module 170 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The speaker 170A, also called "speaker", is used to convert audio electrical signals into sound signals. The receiver 170B, also called "earpiece", is used to convert audio electrical signals into sound signals. The microphone 170C, also called "microphone", "microphone", is used to convert sound signals into electrical signals. The headphone interface 170D is used to connect wired headphones.

The pressure sensor is used to sense the pressure signal and can convert the pressure signal into an electrical signal. The gyroscope sensor can be used to determine the motion posture of the electronic device 100. The air pressure sensor is used to measure the air pressure. The magnetic sensor includes a Hall sensor. The acceleration sensor can detect the magnitude of the acceleration of the electronic device 100 in all directions (generally three axes). Distance sensor, used to measure the distance. The proximity light sensor can include, for example, a light emitting diode (LED) and a light detector, such as a photodiode. The ambient light sensor is used to sense the brightness of the ambient light. The fingerprint sensor is used to collect fingerprints. The temperature sensor is used to detect the temperature. The touch sensor, also known as the "touch panel". The bone conduction sensor can obtain vibration signals. The button 190 includes a power button, a volume button, etc. The motor 191 can generate a vibration prompt. The indicator 192 can be an indicator light, which can be used to indicate the charging status, the change of the power, and can also be used to indicate messages, missed calls, notifications, etc. The display screen 193 is used to display images, videos, etc. The SIM card interface 194 is used to connect the SIM card.

Camera 195 is used to capture still images or videos. The object generates an optical image through the lens and projects it onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the light signal into an electrical signal, and then transmits the electrical signal to the ISP for conversion into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard RGB, YUV or other format.

Further, in one embodiment, taking the operating system of the electronic device 200 as the Android system as an example, as shown in FIG8 , the electronic device 200 can be logically divided into an application layer 21, a kernel layer 22, and a hardware layer 23. Among them, the hardware layer 23 may include the processor 210 and the memory 220 shown in FIG6 . The application layer 21 includes one or more applications (application 1 to application 3, etc.). The application can be a system application or a third-party application. The kernel layer 22 serves as a software middleware between the hardware layer 23 and the application layer 21, and is used to manage and control hardware and software resources, for example, to manage the memory of the electronic device 200.

In some embodiments of the present application, the kernel layer 22 includes a kernel 221, a switching device 222 for providing underlying system services, and a memory management module 223 for managing memory. For example, the switching device 222 may include a ZRAM block device, a zspage module, and a Swap block device. When the memory management module 223 determines that the usage of the memory 2201 exceeds a threshold, the memory management module 223 determines the first cold data according to the LRU algorithm. The memory management module 223 swaps out the first cold data to the ZRAM partition in the memory 2201 through the ZRAM block device. The ZRAM block device (including a compression algorithm) compresses the first cold data in the ZRAM partition. The ZRAM block device stores the compressed first cold data in the ZRAM partition in the memory 2201 in the form of a switching unit (such as a zspage) through the zspage module. Among them, the zspage module records the stored first cold data and the compression rate corresponding to each first cold data. When the ZRAM block device determines that the total amount of compressed data exceeds the compression threshold, it notifies the Swap block device through the interface. The Swap block device obtains the second cold data from the zspage module through an interface (such as the get_cold_zspage interface). The zspage module determines the second cold data that can be swapped out from the first cold data based on the LRU algorithm and the compression ratio. The zspage module sends the second cold data to the Swap block device through an interface (such as the get_cold_zspage interface). The Swap block device swaps out the second cold data to the external memory 2202.

The technical solution provided by the embodiments of the present application is described below in conjunction with the accompanying drawings.

FIG9 is a flowchart of an example of a memory management method provided in an embodiment of the present application, and the memory management method is applied to an electronic device 200. The memory 2201 included in the electronic device 200 may be a first memory in the embodiment of the present application, and the external memory 2202 may be a second memory in the embodiment of the present application. The memory 2201 stores data of applications running in the background.

In the following introduction, the application of the technical solution provided by the present application in the software architecture shown in Figure 7 is used as an example for explanation. As an example, the memory management method provided by the present application can be executed by the kernel 221 shown in Figure 7, or it can be understood that the method can be executed by the processor 210 in the electronic device 200 running the program of the kernel 221.

S11. When the remaining storage space of the memory 2201 is less than a first threshold, the memory management module 223 determines the first cold data in the memory 2201 according to a page replacement algorithm.

It should be noted that in the embodiment of the present application, the remaining storage space is also referred to as available storage space. In the present application, the first cold data can be referred to as first data, and the second cold data can be referred to as second data.

In some example implementations, the memory management module 223 may determine the remaining storage space of the memory 2201 according to the rated storage space and the used storage space of the memory 2201. For example, the remaining storage space is equal to the difference between the rated storage space and the used storage space of the memory 2201.

Generally, after the electronic device 200 is turned on, the start-up phase of application 1 and application 2 includes: after the processor 210 receives the user's operation to start application 1, the processor 210 starts application 1, and the memory management module 223 allocates 30M of storage space for it. Later, when the user wants to open application 2, the processor 210 receives the user's switching operation, switches application 1 to the background, and displays the desktop. At this time, the memory management module 223 determines that the remaining storage space of 70M is greater than the memory recovery threshold (such as 40M), and the processor 210 will not forcibly end application 1. After the processor 210 receives the user's operation to start application 2, the processor 210 starts application 2, and the memory management module 223 allocates 35M of storage space for it.

Afterwards, when the user wants to open application 3, the processor 210 receives the user's switching operation, switches application 2 to the background, and displays the desktop. Since the processor 210 does not kill application 1 and application 2, but continues to run application 1 and application 2 in the background, application 1 and application 2 will still occupy 65M storage space for storing relevant data, such as the data of the last display interface before switching to the background. In this way, as the number of applications running in the background gradually increases, the storage space occupied by the applications running in the background in memory 2201 will also gradually increase, resulting in the remaining storage space of memory 2201 being less than the first threshold. The memory management module 223 determines the first cold data in the memory 2201 according to the page replacement algorithm, and swaps the first cold data out to the Swap space. The ZRAM block device compresses the first cold data in the Swap space, and stores the compressed first cold data in the form of a swap unit (such as a zspage) in the memory 2201. At this time, the memory 2201 can be used to store the data of the application running in the background, as well as the compressed first cold data. Therefore, the used storage space is equal to the sum of the storage space occupied by the data of the application running in the background and the storage space occupied by the compressed first cold data. For example, if the rated storage space of the memory 2201 is 4000M, when the storage space occupied by the data of the application running in the background is 1500M, and the storage space occupied by the compressed first cold data is 300M, then the used storage space is equal to 1500M+300M, and the remaining storage space is equal to 4000M-1800M (1500M+300M), that is, the remaining storage space is 2200M.

It should be noted that after the electronic device 200 is turned on, when the electronic device 200 does not receive an application startup operation, the remaining storage space of the memory 2201 is greater than the first threshold, and the memory management module 223 does not need to determine the first cold data in the memory 2201 according to the page replacement algorithm. Therefore, the memory 2201 will not include the compressed first cold data.

In some example implementations, the first threshold may be determined based on a memory recycling threshold of the electronic device 200 .

For example, the electronic device 200 includes multiple memory recovery thresholds. The first threshold value may be any one of the multiple memory recovery thresholds of the electronic device 200. Alternatively, the first threshold value may be the minimum value of the multiple memory recovery thresholds of the electronic device 200. The first threshold value may be the maximum value of the multiple memory recovery thresholds of the electronic device 200. Alternatively, the first threshold value may be the average value of the multiple memory recovery thresholds of the electronic device 200. Alternatively, the first threshold value may be the sum of the specified memory recovery threshold of the electronic device 200 and a preset value. Here, it is only exemplified how to determine the first threshold value based on multiple memory recovery thresholds, and this application does not limit it here.

Exemplarily, the first threshold value may be the sum of the specified memory recovery threshold value of the electronic device 200 and a preset value. Assume that the electronic device includes three memory recovery thresholds, namely, memory recovery threshold 1, memory recovery threshold 2, and memory recovery threshold 3. Memory recovery threshold 1 is less than memory recovery threshold 2, and memory recovery threshold 2 is less than memory recovery threshold 3. When the specified memory recovery threshold is memory recovery threshold 1, the electronic device 200 determines that the first threshold value is the sum of memory recovery threshold 1 and the specified value. For example, if memory recovery threshold 1 is 1500M and the specified value is 500M, the first threshold value is 2000M.

Of course, when the electronic device 200 includes only one memory recycling threshold, the first threshold is equal to the memory recycling threshold.

In some example implementations, the Android system divides memory into fixed-size management units, such as memory blocks of 4KB, 8KB, 16KB, etc., which are called pages. That is, the data in the memory is stored in the form of pages.

Generally, the data stored in the memory can be referred to as memory pages. As shown in FIG9 , when the processor 210 of the electronic device 200 receives an operation to start application 1, the processor 210 searches for the memory page stored by application 1 in the memory 2201 through an address mapping process. Since the electronic device 200 has swapped out the compressed data of application 1 to the external memory 2202 through the Swap module. At this time, the processor 210 determines that there is no memory page of application 1 in the memory 2201, so a page fault interruption will occur. When a page fault interruption occurs, if there is no free memory page in the memory 2201 of the electronic device 200, the system must select a memory page in the memory 2201 and move it out of the memory 2201 to make room for the page to be called in. Usually, the electronic device 200 determines the memory page that can be swapped out in the memory 2201 according to the page replacement algorithm. The memory page that can be swapped out can be called the first cold data. Among them, the page replacement algorithm can be any one of the LRU algorithm, the optimal replacement algorithm (OPT), and the first in first out replacement algorithm (FIFO).

Exemplarily, when the page replacement algorithm is the LRU algorithm, the memory management module 223 may periodically obtain the remaining storage space of the memory 2201 and determine whether the remaining storage space is less than the first threshold. When the remaining storage space is less than the first threshold, the memory management module 223 may determine the data to be swapped out in the memory 2201 according to the LRU algorithm. For example, the applications running in the background include application 1 and application 2, and the memory management module 223 determines that the data of application 1 in the memory 2201 can be swapped out according to the LRU algorithm, that is, the first cold data is the data of application 1.

S12. The memory management module 223 swaps the first cold data to the Swapspace set in the memory 2201 through the ZRAM block device.

S13. The ZRAM block device compresses the first cold data in the Swap space, stores the compressed first cold data in the memory 2201, and the memory management module 223 releases the storage space occupied by the first cold data.

In some example implementations, after the memory management module 223 determines the data to be swapped out, or the memory management module 223 determines the memory page that can be swapped out, the memory page can be swapped out to the Swap space through the ZRAM block device. Then, the electronic device 200 can compress the memory page in the Swap space through the ZRAM block device, and store the compressed memory page in the memory 2201 again. Afterwards, the memory management module 223 can release the storage space occupied by the memory page before compression. For example: the first cold data is the data of application 1, and the data of application 1 corresponds to memory page 1 and memory page 2. The memory management module 223 swaps out memory page 1 and memory page 2 to the Swap space. Then, the ZRAM block device compresses the memory page 1 and memory page 2 in the Swap space, and stores the compressed memory page 1 and memory page 2 in the memory 2201 again. Afterwards, the memory management module 223 can also release the storage space occupied by the memory page 1 and memory page 2 in the memory 2201 before compression.

In some example implementations, the ZRAM block device stores the compressed first cold data in the first memory in the form of a swap unit, thereby facilitating data management.

Generally, the compression ratios of the compressed first cold data in the same exchange unit are similar, such as the difference is less than the third threshold. For example, the exchange unit is called zspage, and the ZRAM block device uses the Zsmalloc memory allocator to store multiple compressed memory pages whose difference is less than the third threshold in the form of zspage in the memory 2201, thereby improving the utilization rate of the memory 2201. Among them, the zspage does not require physical continuity when stored in the memory 2201.

Exemplarily, the applications running in the background include application 1 and application 2. Furthermore, the data of application 1 corresponds to memory page 1, and the data of application 2 corresponds to memory page 2, memory page 3, and memory page 4. The memory management module 223 determines, based on the LRU algorithm, that the first cold data in memory 2201 includes memory page 1, memory page 2, memory page 3, and memory page 4. The memory management module 223 swaps out memory page 1, memory page 2, memory page 3, and memory page 4 to the Swap space in memory 2201 through the ZRAM block device. Then, the ZRAM block device compresses memory page 1, memory page 2, memory page 3, and memory page 4 in the Swap space. The size of memory page 1 before compression is 4KB, the size of memory page 2 before compression is 3KB, the size of memory page 3 before compression is 4KB, the size of memory page 4 before compression is 2KB, the size of memory page 1 after compression is 3.5KB, the size of memory page 2 after compression is 2.5, the size of memory page 3 after compression is 3.5, and the size of memory page 4 after compression is 2KB. The compression ratio of the compressed memory page 1 is 1. That is 87.5%; the compression ratio 2 corresponding to the compressed memory page 2 is/> That is 83.3%; the compression ratio 3 of the compressed memory page 3 is/> That is 87.5%; the compression ratio 4 of the compressed memory page 4 is/> That is, 100%. When the third threshold is 5%, since the difference between compression ratio 1 and compression ratio 2 (4.2%) is less than 5%, and the difference between compression ratio 1 and compression ratio 3 (0) is less than 5%, and the difference between compression ratio 1 and compression ratio 4 (12.5%) is greater than 5%. Therefore, the Zsmalloc memory allocator is used to store compressed memory page 1, compressed memory page 2, and compressed memory page 3 in the same zspage (such as zspage1), the ZRAM block device stores compressed memory page 4 in other zspages (such as zspages other than zspage1), and the memory management module 223 releases the storage space occupied by memory page 1, memory page 2, memory page 3, and memory page 4 in memory 2201 before compression.

In combination with the above example, when the memory management module 223 determines that the remaining storage space of the memory 2201 is less than the first threshold, the first cold data in the memory 2201 is determined according to the page replacement algorithm. After the memory management module 223 swaps out the first cold data to the Swap space set in the memory 2201 through the ZRAM block device, the ZRAM block device needs to compress the first cold data in the Swap space, because the storage space occupied by the compressed first cold data is usually smaller than the storage space occupied by the first cold data. Therefore, the compressed first cold data is stored in the memory 2201, and the storage space occupied is smaller than the storage space occupied by the first cold data. At the same time, the memory management module 223 releases the storage space occupied by the first cold data, so that more storage space can be released to ensure the normal operation of the electronic device 200.

Exemplarily, as shown in FIG10 , the rated storage space of memory 2201 is 100M, the first threshold is 25M, 25% of memory page 1 of all data currently stored in memory 2201 occupies less than 1KB of storage space after being compressed by the ZRAM block device in the ZRAM partition, 20% of memory page 2 of all data currently stored in memory 2201 occupies less than 2KB of storage space after being compressed by the ZRAM block device in the ZRAM partition, 19% of memory page 3 of all data currently stored in memory 2201 occupies less than 3KB of storage space after being compressed by the ZRAM block device in the ZRAM partition, and 16% of memory page 4 of all data currently stored in memory 2201 occupies less than 4KB of storage space after being compressed by the ZRAM block device in the ZRAM partition.

The memory management module 223 determines that the remaining storage space of the memory 2201 is 100M-(25%+20%+19%+16%)×100M=20M. The memory management module 223 determines that the remaining storage space 20M is less than the first threshold 25M, and the memory management module 223 determines the first cold data in the memory 2201 according to the page replacement algorithm. The first cold data includes all memory pages 1, all memory pages 2, all memory pages 3, and all memory pages 4. The memory management module 223 swaps out the first cold data to the Swap space set in the memory 2201 through the ZRAM block device. The ZRAM block device compresses the first cold data in the Swap space and stores the compressed first cold data in the memory 2201. Among them, the storage space occupied by all memory pages 1 after compression is 100M×3%=3M, the storage space occupied by all memory pages 2 after compression is 100M×7%=7M, the storage space occupied by all memory pages 3 after compression is 100M×14%=14M, and the storage space occupied by all memory pages 4 after compression is 100M×16%=16M. After releasing the storage space occupied by the first cold data, the memory management module 223 determines that the size of the storage space occupied by the first cold data of the compressed user is 3M+7M+14M+16M=40M. It can be seen that the storage space occupied by the first cold data in the memory 2201 after compression is reduced by 40M of storage space compared with the storage space occupied by the first cold data before compression, that is, 40% of the storage space can be saved, and the user experience is better.

S14. When the ZRAM block device determines that the storage space occupied by the compressed first cold data stored in the memory 2201 is greater than the second threshold, it notifies the Swap block device through the interface, and the Swap block device obtains the second cold data from the zspage module through the interface.

S15. The zspage module determines, according to the LRU algorithm and the compression ratio, second cold data that meets a preset condition in the first cold data, and sends the second cold data to the swap block device through an interface.

S16. The Swap module obtains the second cold data from the zspage module, stores the second cold data in the second memory, and the memory management module 223 releases the storage space corresponding to the second cold data.

When the storage space occupied by the compressed first cold data stored in the memory 2201 is greater than the second threshold, it means that there are too many compressed first cold data stored in the memory 2201, resulting in a small available storage space in the memory 2201. To this end, in the memory management method provided in the embodiment of the present application, after the Swap module obtains the second cold data from the zspage module, the second cold data is stored in the second memory. The memory management module 223 releases the storage space corresponding to the second cold data, so that the available storage space of the memory 2201 is larger.

In combination with the above example, when the compressed first cold data is stored in the first memory, it is stored in the form of a switching unit. Generally, each switching unit corresponds to a compression rate. In some examples, the embodiments of the present application store the switching units whose compression rates in the first cold data meet the preset conditions in the second memory, and release the corresponding storage space. In this way, after the ZRAM block device determines the second cold data that meets the preset conditions from the compressed first cold data, it stores the second cold data in the second memory in the form of a switching unit, and releases the corresponding storage space.

In some example implementations, the electronic device 200 stores in the second memory all first cold data in the switching units whose compression rate is greater than a fourth threshold and whose swap-in probability is less than a fifth threshold.

In one example, the swap-in probability of each exchange unit can be determined based on the probability of the first cold data in the exchange unit being accessed. For example, assuming that the swap-in probability of a memory page is p, the probability that all compressed memory pages in the exchange unit are not swapped in is (1-p) ⁿ , where n is the total number of memory pages contained in the exchange unit, and n is an integer greater than or equal to 1. Therefore, the swap-in probability of the exchange unit is 1-(1-p) ⁿ . In conjunction with the above example, the method for determining the compression rate is similar to the above example and will not be repeated here.

Exemplarily, the second memory is UFS, the exchange unit is zspage, the applications running in the background include application 1, application 2 and application 3, the data of application 1 corresponds to memory page 1, the data of application 2 corresponds to memory page 2, memory page 3 and memory page 4, application 3 corresponds to memory page 5 and memory page 6, the size of each memory page before compression is 4KB, the size of each zspage is 4KB, and the maximum value of the compression rate of each first cold data contained in the zspage is the compression rate of the zspage. This is described as an example:

As shown in Figure 11, the memory management module 223 determines that the first cold data in the memory 2201 includes memory page 1, memory page 2, memory page 3, memory page 4, memory page 5 and memory page 6 according to the LRU algorithm. The memory management module 223 swaps out memory page 1, memory page 2, memory page 3, memory page 4, memory page 5 and memory page 6 to the Swap space through the ZRAM block device. The ZRAM block device compresses memory page 1, memory page 2, memory page 3, memory page 4, memory page 5 and memory page 6 in the Swap space. Among them, the size of the compressed memory page 1 is 4KB, the size of the compressed memory page 2 is 2KB, the size of the compressed memory page 3 is 2KB, the size of the compressed memory page 4 is 1.3KB, the size of the compressed memory page 5 is 1.3KB, and the size of the compressed memory page 6 is 1.3KB. Then, the compression rate of memory page 1 is That is 100%; the compression ratio of memory page 2 is/> That is 50%; the compression ratio of memory page 3 is/> That is 50%; the compression ratio of memory page 4 is/> That is 32.5%; the compression ratio of memory page 5 is/> That is 32.5%; the compression ratio of memory page 6 is/> That is, 32.5%. The ZRAM block device usually stores the compressed first cold data in the memory 2201 in the form of zspage.

For example, the ZRAM block device stores memory pages with similar compression rates in the same swap unit in memory 2201. The compression rate of compressed memory page 1 is significantly different from that of other compressed memory pages, and the size of compressed memory page 1 is the same as the size of zspage. The ZRAM block device stores compressed memory page 1 in zspage1 in memory 2201. The compression rate of compressed memory page 2 is the same as that of compressed memory page 3, and the sizes of compressed memory page 2 and compressed memory page 3 are the same as the size of zspage. The ZRAM block device stores compressed memory page 2 and compressed memory page 3 in zspage2 in memory 2201. The compression rates of compressed memory page 4, compressed memory page 5, and compressed memory page 6 are the same, and the sizes of compressed memory page 4, compressed memory page 5, and compressed memory page 6 are similar to the size of zspage. The ZRAM block device stores compressed memory page 4, compressed memory page 5, and compressed memory page 6 in zspage3 in memory 2201. It can be seen that the probability of swapping in zspage1 is 1-(1-p), the probability of swapping in zspage2 is 1-(1-p) ² , and the probability of swapping in zspage 3 is 1-(1-p) ³ .

It can be seen that the greater the compression rate of the memory page, the fewer memory pages that can be stored in the corresponding zspage, which makes the swap-in probability of the zspage lower. In this way, in the memory management method provided by the embodiment of the present application, when the ZRAM block device determines that the compressed first cold data (also called the total amount of compressed data) exceeds the second threshold, the zspage module determines the second cold data that can be swapped out in the compressed first cold data according to the LRU algorithm. Then, according to the swap-in probability of each zspage, determine the data that can be swapped out in the second cold data. For example: the zspage module determines that the second cold data that can be swapped out in the compressed first cold data includes: zspage1, zspage2 and zspage3 according to the LRU algorithm. Since zspage1 contains the least memory pages and the corresponding swap-in probability of zspage1 is the lowest, the compressed data of application 1, i.e. zspage1, is preferentially swapped out to UFS to avoid the problem of data thrashing.

In some other example implementations, the electronic device 200 determines the order in which the switching units are stored in the second memory according to the compression rate of each switching unit until the available storage space of the first memory is greater than the first threshold.

In one example, the compression rate corresponding to the exchange unit can be determined based on the compression rate of the compressed first cold data in the exchange unit. For example, the average value of the compression rate of each first cold data contained in the exchange unit is used as the compression rate of the exchange unit; or, the maximum value of the compression rate of each first cold data contained in an exchange unit is used as the compression rate of the exchange unit; or, the variance of the compression rate of each first cold data contained in an exchange unit is used as the compression rate of the exchange unit. Here, it is only an example of how to determine the compression rate of an exchange unit based on the compression rate of each first cold data contained in the exchange unit, and this application does not limit it here.

In one example, the zspage module stores the compressed second cold data in the exchange unit in descending order according to the compression rate of each exchange unit. After the Swap module obtains the second cold data from the zspage module, it stores the second cold data in the second memory until the available storage space of the first memory is greater than the first threshold.

Exemplarily, the example of taking the average compression rate of each first cold data contained in the exchange unit as the compression rate of the exchange unit is used for explanation. According to the description of the above example, it can be seen that the compression rate of zspage1 is the largest, so the zspage module first sends zspage1 to the Swap module. After the Swap module obtains zspage1 from the zspage module, it stores zspage1 in the UFS, and the memory management module 223 releases the storage space occupied by zspage1 in the memory 2201. At this time, the memory management module 223 determines that the remaining storage space of the memory 2201 is greater than the first threshold, and zspage1 does not need to be swapped out. If the Swap module stores zspage1 in the UFS, and the memory management module 223 determines that the remaining storage space of the memory 2201 is less than the first threshold, the zspage module continues to send zspage2 to the Swap module. After the Swap module obtains zspage2 from the zspage module, it stores zspage2 in the UFS, and the memory management module 223 releases the storage space occupied by zspage2 in the memory 2201. At this time, the memory management module 223 determines that the remaining storage space of the memory 2201 is greater than the first threshold, and the zspage module does not need to swap out zspage. And so on, no further details are given here.

In some other example implementations, the zspage module determines the swap units to be swapped out in the memory 2201 according to a page replacement algorithm, and then determines the order in which the swap units are stored in the second memory according to the compression rate of each swap unit, until the available storage space of the first memory is greater than a first threshold.

In one example, the zspage module determines the switching units to be swapped out in the memory 2201 according to the LRU algorithm, and then stores the first cold data in the switching units in the second memory in descending order according to the compression rate of each switching unit to be swapped out until the available storage space of the first memory is greater than the first threshold.

Exemplarily, when there are many exchange units to be swapped out stored in the memory 2201, the zspage module needs to determine the compression rate of each exchange unit to be swapped out, which will consume a lot of computing resources. To this end, in the memory management method provided by the embodiment of the present application, the zspage module determines the exchange units to be swapped out in the memory 2201 according to the LRU algorithm, and then stores the compressed first cold data in the exchange unit in the second memory in a descending order according to the compression rate of each exchange unit to be swapped out, until the available storage space of the first memory is greater than the first threshold. There is no need to calculate the compression rate of each exchange unit to be swapped out, and while reducing the occupied computing resources, the swapping efficiency of the electronic device 200 is improved.

Generally, each switching unit corresponds to an activity. In some examples, the embodiments of the present application store the switching units whose activities satisfy the preset conditions in the first cold data in the second memory, and release the corresponding storage space.

In some other example implementations, the electronic device 200 moves unaccessed memory pages, such as memory pages that have not been accessed in a recent period of time, from an active LRU list (Active LRU List) to the head of an inactive LRU list (InactiveLRU List), and determines the swappable memory pages in the inactive LRU list.

In one example, the electronic device 200 swaps out memory pages in sequence starting from the end of the inactive LRU linked list.

Exemplarily, taking the page replacement algorithm as the LRU algorithm as an example, when the electronic device 200 determines that the remaining storage space of the memory 2201 is less than the first threshold, the electronic device 200 determines according to the LRU algorithm that the compressed zspage3 can be swapped out. At this time, the electronic device 200 moves the zspage3 in the active LRU linked list shown in Table 1 to the head of the inactive LRU linked list shown in Table 2.

Table 1 Active LRU linked list

Compressed page Recently visited zspage1 yes zspage2 yes zspage3 no

Table 2 Inactive LRU linked list

Compressed page Recently visited zspage4 no zspage5 no

Table 3 Inactive LRU linked list

Compressed page Recently visited zspage3 no zspage4 no zspage5 no

Table 4 Inactive LRU linked list

Compressed page Recently visited zspage3 no zspage4 no

At this time, after zspage3 is moved to the head of the inactive LRU linked list as shown in Table 2, the inactive LRU linked list is as shown in Table 3. In Table 3, zspage5 is located at the tail of the inactive LRU linked list. The electronic device 200 stores zspage5 in the UFS and releases the storage space occupied by zspage5 in the memory 2201. The updated inactive LRU linked list is shown in Table 4. If the remaining storage space of the memory 2201 is greater than the first threshold, the electronic device 200 does not need to swap out the zspage. If the remaining storage space of the memory 2201 is still less than the first threshold after the electronic device 200 stores zspage5 in the UFS, the electronic device 200 stores zspage4 in the UFS and releases the storage space occupied by zspage4 in the memory 2201. If the remaining storage space of the memory 2201 is greater than the first threshold, the electronic device 200 does not need to swap out the zspage. And so on, it will not be repeated here.

It should be noted that, as shown in FIG9 , the data phase of swapping in application 1 includes: processing 210 obtains data of application 1 from memory management module 223. Memory management module 223 determines that data of application 1 does not exist in memory 2201. Memory management module 223 determines that data of application 1 exists in Swap block device. Swap block device obtains compressed data of application 1 from external memory 2202. Swap block device receives compressed data of application 1 from external memory 2202. Swap block device sends compressed data of application 1 to zspage module. ZRAM block device obtains compressed data of application 1 from Swap block device. ZRAM block device receives compressed data of application 1 from Swap block device. ZRAM block device stores compressed data of application 1 in Swap spac in memory 2201, also called ZRAM partition. ZRAM block device decompresses compressed data of application 1 in ZRAM partition. ZRAM block device swaps out decompressed data of application 1 to memory 2201. Memory 2201 receives decompressed data of application 1 sent by ZRAM block device. The memory management module 223 sends the decompressed data of the application 1 in the memory 2201 to the processor 210. The processor 210 displays the data of the last display interface of the application 1 according to the decompressed data of the application 1 sent by the memory management module 223.

It is understandable that, in order to realize the above functions, the above electronic device includes hardware structures and/or software modules corresponding to the execution of each function. Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiments of the present application.

The embodiment of the present application can divide the functional modules of the above-mentioned electronic device according to the above-mentioned method example. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

In an example, please refer to FIG12 , which is a schematic diagram of the composition of an electronic device 10 provided in an embodiment of the present application. As shown in FIG12 , the electronic device 10 may include: a processing unit 101 .

The processing unit 101 is used to compress the first data in the data and store it in the first memory when the available storage space of the first memory is less than the first threshold. The processing unit 101 is also used to release the storage space occupied by the first data before compression. The processing unit 101 is also used to store the second data in the second memory when the storage space occupied by the compressed data in the first memory is greater than the second threshold, the second data being the data in the compressed data in the first memory whose compression rate meets the threshold condition, and the compressed data in the first memory includes the first data. The processing unit 101 is also used to release the storage space occupied by the second data.

In a possible implementation, the processing unit 101 is specifically configured to compress the first data; the processing unit 101 is specifically configured to store the compressed first data in the form of an exchange unit in the first memory, wherein the compression rate difference of the compressed first data in the same exchange unit is less than a third threshold.

In a possible implementation, the processing unit 101 is specifically configured to determine that all compressed first data in the switching unit whose compression rate is greater than a fourth threshold value is the second data. The processing unit 101 is specifically configured to store the second data in the second memory. The compression rate of each switching unit is determined according to the compression rate of the compressed first data in the switching unit.

In a possible implementation, the processing unit 101 is specifically configured to determine that all compressed first data in the switching unit whose compression rate is greater than a fourth threshold value and whose swap-in probability is less than a fifth threshold value is the second data. The processing unit 101 is specifically configured to store the second data in the second memory. The compression rate of each switching unit is determined based on the compression rate of the compressed first data in the switching unit, and the swap-in probability of each switching unit is determined based on the probability of the compressed first data in the switching unit being accessed.

In one possible implementation, the processing unit 101 is specifically used to determine, based on the compression rate of each exchange unit, that the second data is the first data compressed in the exchange unit in order from large to small; the processing unit 101 is specifically used to store the second data in the second memory in sequence until the available storage space of the first memory is greater than the first threshold.

In a possible implementation, the first memory is a memory, and the second memory is an external memory.

Of course, the electronic device 10 provided in the embodiment of the present invention includes but is not limited to the above modules, for example, the electronic device 10 may also include a storage unit 102. The storage unit 102 may be used to store the program code of the electronic device 10, and may also be used to store data generated by the electronic device 10 during operation, such as data in a write request.

The embodiment of the present application also provides an electronic device, which may include: a processor and a memory, wherein the memory includes an internal memory and an external memory. The memory is used to store computer program code, and the computer program code includes computer instructions. When the processor executes the computer instructions, the electronic device can execute the various functions or steps executed by the mobile phone in the above method embodiment. Of course, the electronic device includes but is not limited to the above display screen, memory and one or more processors. For example, the structure of the electronic device can refer to the structure of the mobile phone shown in Figure 5.

The embodiment of the present application also provides a chip system, which can be applied to the electronic devices in the aforementioned embodiments. As shown in Figure 13, the chip system includes at least one processor 1501 and at least one interface circuit 1502. The processor 1501 can be the processor in the above-mentioned electronic device. The processor 1501 and the interface circuit 1502 can be interconnected through a line. The processor 1501 can receive and execute computer instructions from the memory of the above-mentioned electronic device through the interface circuit 1502. When the computer instructions are executed by the processor 1501, the electronic device can execute the various steps executed by the mobile phone in the above-mentioned embodiment. Of course, the chip system can also include other discrete devices, which are not specifically limited in the embodiment of the present application.

The embodiment of the present application also provides a computer-readable storage medium for storing computer instructions executed by the above-mentioned electronic device (such as a mobile phone).

An embodiment of the present application also provides a computer program product, including computer instructions executed by the above-mentioned electronic device (such as a mobile phone).

Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (7)

1. A memory management method, applied to an electronic device, the electronic device comprising a first memory and a second memory, wherein the first memory stores data of an application running in the background; the method comprising: When the available storage space of the first memory is less than a first threshold, the electronic device compresses the first data in the data, and stores the data whose compression rate difference in the compressed first data is less than a third threshold in the first memory using the same exchange unit; The electronic device releases the storage space occupied by the first data before compression; When the storage space occupied by the compressed data in the first memory is greater than a second threshold, the electronic device stores the second data stored in the target exchange unit in the second memory in descending order of the compression rates of the exchange units, and releases the storage space occupied by the second data in the first memory until the available storage space of the first memory is greater than the first threshold; the compression rate of the target exchange unit is greater than a fourth threshold, and the compression rate of the exchange unit is determined based on the compression rate of the compressed data in the exchange unit. 2. The method according to claim 1 is characterized in that the swap-in probability of the target swap unit is less than a fifth threshold, the swap-in probability of the target swap unit is 1-(1-p) ⁿ , n is the total number of memory pages contained in the target swap unit, n is an integer greater than or equal to 1, p is the swap-in probability of a memory page, and the compressed data in the first memory includes the first data. 3 . The method according to claim 1 , wherein the first memory is a memory and the second memory is an external memory. 4. The method according to claim 1, characterized in that the electronic device further comprises a ZRAM block device, a zspage module, a Swap block device and a memory management module, and the method comprises: When the available storage space of the first memory is less than a first threshold, the memory management module stores the first data in the Swap space set in the first memory through the ZRAM block device; The ZRAM block device compresses the first data in the Swap space, and sends the compressed first data to the zspage module; The zspage module stores the data whose compression ratio difference in the compressed first data is less than a third threshold in the first memory using the same exchange unit; The memory management module releases the storage space occupied by the first data before compression; When the storage space occupied by the compressed data in the first memory is greater than a second threshold, the ZRAM block device notifies the Swap block device through the interface; The Swap block device obtains the second data stored in the target swap unit from the zspage module through an interface; The zspage module sends the second data stored in the target exchange unit to the Swap block device in order of compression rates of the exchange units from large to small; the compression rate of the exchange unit is determined according to the compression rate of the compressed data in the exchange unit; The Swap block device stores the second data in the second memory, and the compressed data in the first memory includes the first data; The memory management module releases the storage space occupied by the second data until the available storage space of the first memory is greater than the first threshold. 5. An electronic device, characterized in that it comprises: a unit for executing each step of the method described in any one of claims 1 to 4. 6. An electronic device, characterized in that it comprises: a communication interface, a processor, a memory, and a bus; The memory is used to store computer-executable instructions, and the processor is connected to the memory via the bus; When the electronic device is running, the processor executes the computer-executable instructions stored in the memory, so that the electronic device executes the memory management method as described in any one of claims 1 to 4 above. 7. A computer-readable storage medium, characterized in that when the instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the memory management method as described in any one of claims 1 to 4.