diff options
Diffstat (limited to 'Documentation')
38 files changed, 2239 insertions, 236 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power new file mode 100644 index 00000000000..78c7baca358 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-power @@ -0,0 +1,20 @@ +What: /sys/class/power/ds2760-battery.*/charge_now +Date: May 2010 +KernelVersion: 2.6.35 +Contact: Daniel Mack <daniel@caiaq.de> +Description: + This file is writeable and can be used to set the current + coloumb counter value inside the battery monitor chip. This + is needed for unavoidable corrections of aging batteries. + A userspace daemon can monitor the battery charging logic + and once the counter drops out of considerable bounds, take + appropriate action. + +What: /sys/class/power/ds2760-battery.*/charge_full +Date: May 2010 +KernelVersion: 2.6.35 +Contact: Daniel Mack <daniel@caiaq.de> +Description: + This file is writeable and can be used to set the assumed + battery 'full level'. As batteries age, this value has to be + amended over time. diff --git a/Documentation/ABI/testing/sysfs-devices-node b/Documentation/ABI/testing/sysfs-devices-node new file mode 100644 index 00000000000..453a210c3ce --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-node @@ -0,0 +1,7 @@ +What: /sys/devices/system/node/nodeX/compact +Date: February 2010 +Contact: Mel Gorman <mel@csn.ul.ie> +Description: + When this file is written to, all memory within that node + will be compacted. When it completes, memory will be freed + into blocks which have as many contiguous pages as possible diff --git a/Documentation/ABI/testing/sysfs-firmware-sfi b/Documentation/ABI/testing/sysfs-firmware-sfi new file mode 100644 index 00000000000..4be7d44aeac --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-sfi @@ -0,0 +1,15 @@ +What: /sys/firmware/sfi/tables/ +Date: May 2010 +Contact: Len Brown <lenb@kernel.org> +Description: + SFI defines a number of small static memory tables + so the kernel can get platform information from firmware. + + The tables are defined in the latest SFI specification: + http://simplefirmware.org/documentation + + While the tables are used by the kernel, user-space + can observe them this way: + + # cd /sys/firmware/sfi/tables + # cat $TABLENAME > $TABLENAME.bin diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index 2e435adfbd6..98ce51796f7 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -639,6 +639,36 @@ is planned to completely remove virt_to_bus() and bus_to_virt() as they are entirely deprecated. Some ports already do not provide these as it is impossible to correctly support them. + Handling Errors + +DMA address space is limited on some architectures and an allocation +failure can be determined by: + +- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0 + +- checking the returned dma_addr_t of dma_map_single and dma_map_page + by using dma_mapping_error(): + + dma_addr_t dma_handle; + + dma_handle = dma_map_single(dev, addr, size, direction); + if (dma_mapping_error(dev, dma_handle)) { + /* + * reduce current DMA mapping usage, + * delay and try again later or + * reset driver. + */ + } + +Networking drivers must call dev_kfree_skb to free the socket buffer +and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook +(ndo_start_xmit). This means that the socket buffer is just dropped in +the failure case. + +SCSI drivers must return SCSI_MLQUEUE_HOST_BUSY if the DMA mapping +fails in the queuecommand hook. This means that the SCSI subsystem +passes the command to the driver again later. + Optimizing Unmap State Space Consumption On many platforms, dma_unmap_{single,page}() is simply a nop. @@ -703,42 +733,25 @@ to "Closing". 1) Struct scatterlist requirements. - Struct scatterlist must contain, at a minimum, the following - members: - - struct page *page; - unsigned int offset; - unsigned int length; - - The base address is specified by a "page+offset" pair. - - Previous versions of struct scatterlist contained a "void *address" - field that was sometimes used instead of page+offset. As of Linux - 2.5., page+offset is always used, and the "address" field has been - deleted. - -2) More to come... - - Handling Errors - -DMA address space is limited on some architectures and an allocation -failure can be determined by: - -- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0 - -- checking the returned dma_addr_t of dma_map_single and dma_map_page - by using dma_mapping_error(): - - dma_addr_t dma_handle; - - dma_handle = dma_map_single(dev, addr, size, direction); - if (dma_mapping_error(dev, dma_handle)) { - /* - * reduce current DMA mapping usage, - * delay and try again later or - * reset driver. - */ - } + Don't invent the architecture specific struct scatterlist; just use + <asm-generic/scatterlist.h>. You need to enable + CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs + (including software IOMMU). + +2) ARCH_KMALLOC_MINALIGN + + Architectures must ensure that kmalloc'ed buffer is + DMA-safe. Drivers and subsystems depend on it. If an architecture + isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in + the CPU cache is identical to data in main memory), + ARCH_KMALLOC_MINALIGN must be set so that the memory allocator + makes sure that kmalloc'ed buffer doesn't share a cache line with + the others. See arch/arm/include/asm/cache.h as an example. + + Note that ARCH_KMALLOC_MINALIGN is about DMA memory alignment + constraints. You don't need to worry about the architecture data + alignment constraints (e.g. the alignment constraints about 64-bit + objects). Closing diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl index 133cd6c3f3c..020ac80d468 100644 --- a/Documentation/DocBook/mtdnand.tmpl +++ b/Documentation/DocBook/mtdnand.tmpl @@ -269,7 +269,7 @@ static void board_hwcontrol(struct mtd_info *mtd, int cmd) information about the device. </para> <programlisting> -int __init board_init (void) +static int __init board_init (void) { struct nand_chip *this; int err = 0; diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist index 8916ca48bc9..da0382daa39 100644 --- a/Documentation/SubmitChecklist +++ b/Documentation/SubmitChecklist @@ -18,6 +18,8 @@ kernel patches. 2b: Passes allnoconfig, allmodconfig +2c: Builds successfully when using O=builddir + 3: Builds on multiple CPU architectures by using local cross-compile tools or some other build farm. @@ -95,3 +97,13 @@ kernel patches. 25: If any ioctl's are added by the patch, then also update Documentation/ioctl/ioctl-number.txt. + +26: If your modified source code depends on or uses any of the kernel + APIs or features that are related to the following kconfig symbols, + then test multiple builds with the related kconfig symbols disabled + and/or =m (if that option is available) [not all of these at the + same time, just various/random combinations of them]: + + CONFIG_SMP, CONFIG_SYSFS, CONFIG_PROC_FS, CONFIG_INPUT, CONFIG_PCI, + CONFIG_BLOCK, CONFIG_PM, CONFIG_HOTPLUG, CONFIG_MAGIC_SYSRQ, + CONFIG_NET, CONFIG_INET=n (but latter with CONFIG_NET=y) diff --git a/Documentation/SubmittingDrivers b/Documentation/SubmittingDrivers index 99e72a81fa2..4947fd8fb18 100644 --- a/Documentation/SubmittingDrivers +++ b/Documentation/SubmittingDrivers @@ -130,6 +130,8 @@ Linux kernel master tree: ftp.??.kernel.org:/pub/linux/kernel/... ?? == your country code, such as "us", "uk", "fr", etc. + http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git + Linux kernel mailing list: linux-kernel@vger.kernel.org [mail majordomo@vger.kernel.org to subscribe] @@ -160,3 +162,6 @@ How to NOT write kernel driver by Arjan van de Ven: Kernel Janitor: http://janitor.kernelnewbies.org/ + +GIT, Fast Version Control System: + http://git-scm.com/ diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt new file mode 100644 index 00000000000..dfab71848dc --- /dev/null +++ b/Documentation/acpi/apei/einj.txt @@ -0,0 +1,59 @@ + APEI Error INJection + ~~~~~~~~~~~~~~~~~~~~ + +EINJ provides a hardware error injection mechanism +It is very useful for debugging and testing of other APEI and RAS features. + +To use EINJ, make sure the following are enabled in your kernel +configuration: + +CONFIG_DEBUG_FS +CONFIG_ACPI_APEI +CONFIG_ACPI_APEI_EINJ + +The user interface of EINJ is debug file system, under the +directory apei/einj. The following files are provided. + +- available_error_type + Reading this file returns the error injection capability of the + platform, that is, which error types are supported. The error type + definition is as follow, the left field is the error type value, the + right field is error description. + + 0x00000001 Processor Correctable + 0x00000002 Processor Uncorrectable non-fatal + 0x00000004 Processor Uncorrectable fatal + 0x00000008 Memory Correctable + 0x00000010 Memory Uncorrectable non-fatal + 0x00000020 Memory Uncorrectable fatal + 0x00000040 PCI Express Correctable + 0x00000080 PCI Express Uncorrectable fatal + 0x00000100 PCI Express Uncorrectable non-fatal + 0x00000200 Platform Correctable + 0x00000400 Platform Uncorrectable non-fatal + 0x00000800 Platform Uncorrectable fatal + + The format of file contents are as above, except there are only the + available error type lines. + +- error_type + This file is used to set the error type value. The error type value + is defined in "available_error_type" description. + +- error_inject + Write any integer to this file to trigger the error + injection. Before this, please specify all necessary error + parameters. + +- param1 + This file is used to set the first error parameter value. Effect of + parameter depends on error_type specified. For memory error, this is + physical memory address. + +- param2 + This file is used to set the second error parameter value. Effect of + parameter depends on error_type specified. For memory error, this is + physical memory address mask. + +For more information about EINJ, please refer to ACPI specification +version 4.0, section 17.5. diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt index 2af2cf39915..816d6071669 100644 --- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt +++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt @@ -12,6 +12,8 @@ Introduction of the s3c2410 GPIO system, please read the Samsung provided data-sheet/users manual to find out the complete list. + See Documentation/arm/Samsung/GPIO.txt for the core implemetation. + GPIOLIB ------- @@ -24,8 +26,60 @@ GPIOLIB listed below will be removed (they may be marked as __deprecated in the near future). - - s3c2410_gpio_getpin - - s3c2410_gpio_setpin + The following functions now either have a s3c_ specific variant + or are merged into gpiolib. See the definitions in + arch/arm/plat-samsung/include/plat/gpio-cfg.h: + + s3c2410_gpio_setpin() gpio_set_value() or gpio_direction_output() + s3c2410_gpio_getpin() gpio_get_value() or gpio_direction_input() + s3c2410_gpio_getirq() gpio_to_irq() + s3c2410_gpio_cfgpin() s3c_gpio_cfgpin() + s3c2410_gpio_getcfg() s3c_gpio_getcfg() + s3c2410_gpio_pullup() s3c_gpio_setpull() + + +GPIOLIB conversion +------------------ + +If you need to convert your board or driver to use gpiolib from the exiting +s3c2410 api, then here are some notes on the process. + +1) If your board is exclusively using an GPIO, say to control peripheral + power, then it will require to claim the gpio with gpio_request() before + it can use it. + + It is recommended to check the return value, with at least WARN_ON() + during initialisation. + +2) The s3c2410_gpio_cfgpin() can be directly replaced with s3c_gpio_cfgpin() + as they have the same arguments, and can either take the pin specific + values, or the more generic special-function-number arguments. + +3) s3c2410_gpio_pullup() changs have the problem that whilst the + s3c2410_gpio_pullup(x, 1) can be easily translated to the + s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0) + are not so easy. + + The s3c2410_gpio_pullup(x, 0) case enables the pull-up (or in the case + of some of the devices, a pull-down) and as such the new API distinguishes + between the UP and DOWN case. There is currently no 'just turn on' setting + which may be required if this becomes a problem. + +4) s3c2410_gpio_setpin() can be replaced by gpio_set_value(), the old call + does not implicitly configure the relevant gpio to output. The gpio + direction should be changed before using gpio_set_value(). + +5) s3c2410_gpio_getpin() is replaceable by gpio_get_value() if the pin + has been set to input. It is currently unknown what the behaviour is + when using gpio_get_value() on an output pin (s3c2410_gpio_getpin + would return the value the pin is supposed to be outputting). + +6) s3c2410_gpio_getirq() should be directly replacable with the + gpio_to_irq() call. + +The s3c2410_gpio and gpio_ calls have always operated on the same gpio +numberspace, so there is no problem with converting the gpio numbering +between the calls. Headers @@ -54,6 +108,11 @@ PIN Numbers eg S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell the GPIO functions which pin is to be used. + With the conversion to gpiolib, there is no longer a direct conversion + from gpio pin number to register base address as in earlier kernels. This + is due to the number space required for newer SoCs where the later + GPIOs are not contiguous. + Configuring a pin ----------------- @@ -71,6 +130,8 @@ Configuring a pin which would turn GPA(0) into the lowest Address line A0, and set GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line. + The s3c_gpio_cfgpin() call is a functional replacement for this call. + Reading the current configuration --------------------------------- @@ -82,6 +143,9 @@ Reading the current configuration The return value will be from the same set of values which can be passed to s3c2410_gpio_cfgpin(). + The s3c_gpio_getcfg() call should be a functional replacement for + this call. + Configuring a pull-up resistor ------------------------------ @@ -95,6 +159,10 @@ Configuring a pull-up resistor Where the to value is zero to set the pull-up off, and 1 to enable the specified pull-up. Any other values are currently undefined. + The s3c_gpio_setpull() offers similar functionality, but with the + ability to encode whether the pull is up or down. Currently there + is no 'just on' state, so up or down must be selected. + Getting the state of a PIN -------------------------- @@ -106,6 +174,9 @@ Getting the state of a PIN This will return either zero or non-zero. Do not count on this function returning 1 if the pin is set. + This call is now implemented by the relevant gpiolib calls, convert + your board or driver to use gpiolib. + Setting the state of a PIN -------------------------- @@ -117,6 +188,9 @@ Setting the state of a PIN Which sets the given pin to the value. Use 0 to write 0, and 1 to set the output to 1. + This call is now implemented by the relevant gpiolib calls, convert + your board or driver to use gpiolib. + Getting the IRQ number associated with a PIN -------------------------------------------- @@ -128,6 +202,9 @@ Getting the IRQ number associated with a PIN Note, not all pins have an IRQ. + This call is now implemented by the relevant gpiolib calls, convert + your board or driver to use gpiolib. + Authour ------- diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt index 081892df4fd..c12bfc1a00c 100644 --- a/Documentation/arm/Samsung-S3C24XX/Overview.txt +++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt @@ -8,10 +8,16 @@ Introduction The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported by the 's3c2410' architecture of ARM Linux. Currently the S3C2410, - S3C2412, S3C2413, S3C2440, S3C2442 and S3C2443 devices are supported. + S3C2412, S3C2413, S3C2416 S3C2440, S3C2442, S3C2443 and S3C2450 devices + are supported. Support for the S3C2400 and S3C24A0 series are in progress. + The S3C2416 and S3C2450 devices are very similar and S3C2450 support is + included under the arch/arm/mach-s3c2416 directory. Note, whilst core + support for these SoCs is in, work on some of the extra peripherals + and extra interrupts is still ongoing. + Configuration ------------- @@ -209,6 +215,13 @@ GPIO Newer kernels carry GPIOLIB, and support is being moved towards this with some of the older support in line to be removed. + As of v2.6.34, the move towards using gpiolib support is almost + complete, and very little of the old calls are left. + + See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific + support and Documentation/arm/Samsung/GPIO.txt for the core Samsung + implementation. + Clock Management ---------------- diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt new file mode 100644 index 00000000000..05850c62abe --- /dev/null +++ b/Documentation/arm/Samsung/GPIO.txt @@ -0,0 +1,42 @@ + Samsung GPIO implementation + =========================== + +Introduction +------------ + +This outlines the Samsung GPIO implementation and the architecture +specfic calls provided alongisde the drivers/gpio core. + + +S3C24XX (Legacy) +---------------- + +See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information +about these devices. Their implementation is being brought into line +with the core samsung implementation described in this document. + + +GPIOLIB integration +------------------- + +The gpio implementation uses gpiolib as much as possible, only providing +specific calls for the items that require Samsung specific handling, such +as pin special-function or pull resistor control. + +GPIO numbering is synchronised between the Samsung and gpiolib system. + + +PIN configuration +----------------- + +Pin configuration is specific to the Samsung architecutre, with each SoC +registering the necessary information for the core gpio configuration +implementation to configure pins as necessary. + +The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a +driver or machine to change gpio configuration. + +See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information +on these functions. + + diff --git a/Documentation/arm/Samsung/Overview.txt b/Documentation/arm/Samsung/Overview.txt index 7cced1fea9c..c3094ea51aa 100644 --- a/Documentation/arm/Samsung/Overview.txt +++ b/Documentation/arm/Samsung/Overview.txt @@ -13,9 +13,10 @@ Introduction - S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list - S3C64XX: S3C6400 and S3C6410 - - S5PC6440 - - S5PC100 and S5PC110 support is currently being merged + - S5P6440 + - S5P6442 + - S5PC100 + - S5PC110 / S5PV210 S3C24XX Systems @@ -35,7 +36,10 @@ Configuration unifying all the SoCs into one kernel. s5p6440_defconfig - S5P6440 specific default configuration + s5p6442_defconfig - S5P6442 specific default configuration s5pc100_defconfig - S5PC100 specific default configuration + s5pc110_defconfig - S5PC110 specific default configuration + s5pv210_defconfig - S5PV210 specific default configuration Layout @@ -50,18 +54,27 @@ Layout specific information. It contains the base clock, GPIO and device definitions to get the system running. - plat-s3c is the s3c24xx/s3c64xx platform directory, although it is currently - involved in other builds this will be phased out once the relevant code is - moved elsewhere. - plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs. - plat-s3c64xx is for the s3c64xx specific bits, see the S3C24XX docs. + plat-s5p is for s5p specific builds, and contains common support for the + S5P specific systems. Not all S5Ps use all the features in this directory + due to differences in the hardware. + + +Layout changes +-------------- + + The old plat-s3c and plat-s5pc1xx directories have been removed, with + support moved to either plat-samsung or plat-s5p as necessary. These moves + where to simplify the include and dependency issues involved with having + so many different platform directories. - plat-s5p is for s5p specific builds, more to be added. + It was decided to remove plat-s5pc1xx as some of the support was already + in plat-s5p or plat-samsung, with the S5PC110 support added with S5PV210 + the only user was the S5PC100. The S5PC100 specific items where moved to + arch/arm/mach-s5pc100. - [ to finish ] Port Contributors diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 57444c2609f..b34823ff164 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -339,7 +339,7 @@ To mount a cgroup hierarchy with all available subsystems, type: The "xxx" is not interpreted by the cgroup code, but will appear in /proc/mounts so may be any useful identifying string that you like. -To mount a cgroup hierarchy with just the cpuset and numtasks +To mount a cgroup hierarchy with just the cpuset and memory subsystems, type: # mount -t cgroup -o cpuset,memory hier1 /dev/cgroup diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 6cab1f29da4..7781857dc94 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -1,18 +1,15 @@ Memory Resource Controller NOTE: The Memory Resource Controller has been generically been referred -to as the memory controller in this document. Do not confuse memory controller -used here with the memory controller that is used in hardware. + to as the memory controller in this document. Do not confuse memory + controller used here with the memory controller that is used in hardware. -Salient features - -a. Enable control of Anonymous, Page Cache (mapped and unmapped) and - Swap Cache memory pages. -b. The infrastructure allows easy addition of other types of memory to control -c. Provides *zero overhead* for non memory controller users -d. Provides a double LRU: global memory pressure causes reclaim from the - global LRU; a cgroup on hitting a limit, reclaims from the per - cgroup LRU +(For editors) +In this document: + When we mention a cgroup (cgroupfs's directory) with memory controller, + we call it "memory cgroup". When you see git-log and source code, you'll + see patch's title and function names tend to use "memcg". + In this document, we avoid using it. Benefits and Purpose of the memory controller @@ -33,6 +30,45 @@ d. A CD/DVD burner could control the amount of memory used by the e. There are several other use cases, find one or use the controller just for fun (to learn and hack on the VM subsystem). +Current Status: linux-2.6.34-mmotm(development version of 2010/April) + +Features: + - accounting anonymous pages, file caches, swap caches usage and limiting them. + - private LRU and reclaim routine. (system's global LRU and private LRU + work independently from each other) + - optionally, memory+swap usage can be accounted and limited. + - hierarchical accounting + - soft limit + - moving(recharging) account at moving a task is selectable. + - usage threshold notifier + - oom-killer disable knob and oom-notifier + - Root cgroup has no limit controls. + + Kernel memory and Hugepages are not under control yet. We just manage + pages on LRU. To add more controls, we have to take care of performance. + +Brief summary of control files. + + tasks # attach a task(thread) and show list of threads + cgroup.procs # show list of processes + cgroup.event_control # an interface for event_fd() + memory.usage_in_bytes # show current memory(RSS+Cache) usage. + memory.memsw.usage_in_bytes # show current memory+Swap usage + memory.limit_in_bytes # set/show limit of memory usage + memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage + memory.failcnt # show the number of memory usage hits limits + memory.memsw.failcnt # show the number of memory+Swap hits limits + memory.max_usage_in_bytes # show max memory usage recorded + memory.memsw.usage_in_bytes # show max memory+Swap usage recorded + memory.soft_limit_in_bytes # set/show soft limit of memory usage + memory.stat # show various statistics + memory.use_hierarchy # set/show hierarchical account enabled + memory.force_empty # trigger forced move charge to parent + memory.swappiness # set/show swappiness parameter of vmscan + (See sysctl's vm.swappiness) + memory.move_charge_at_immigrate # set/show controls of moving charges + memory.oom_control # set/show oom controls. + 1. History The memory controller has a long history. A request for comments for the memory @@ -106,14 +142,14 @@ the necessary data structures and check if the cgroup that is being charged is over its limit. If it is then reclaim is invoked on the cgroup. More details can be found in the reclaim section of this document. If everything goes well, a page meta-data-structure called page_cgroup is -allocated and associated with the page. This routine also adds the page to -the per cgroup LRU. +updated. page_cgroup has its own LRU on cgroup. +(*) page_cgroup structure is allocated at boot/memory-hotplug time. 2.2.1 Accounting details All mapped anon pages (RSS) and cache pages (Page Cache) are accounted. -(some pages which never be reclaimable and will not be on global LRU - are not accounted. we just accounts pages under usual vm management.) +Some pages which are never reclaimable and will not be on the global LRU +are not accounted. We just account pages under usual VM management. RSS pages are accounted at page_fault unless they've already been accounted for earlier. A file page will be accounted for as Page Cache when it's @@ -121,12 +157,19 @@ inserted into inode (radix-tree). While it's mapped into the page tables of processes, duplicate accounting is carefully avoided. A RSS page is unaccounted when it's fully unmapped. A PageCache page is -unaccounted when it's removed from radix-tree. +unaccounted when it's removed from radix-tree. Even if RSS pages are fully +unmapped (by kswapd), they may exist as SwapCache in the system un |