diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-memory | 51 | ||||
| -rw-r--r-- | Documentation/DMA-mapping.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/Locking | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 26 | ||||
| -rw-r--r-- | Documentation/hwmon/adt7470 | 19 | ||||
| -rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 8 | ||||
| -rw-r--r-- | Documentation/kernel-doc-nano-HOWTO.txt | 34 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 29 | ||||
| -rw-r--r-- | Documentation/kprobes.txt | 5 | ||||
| -rw-r--r-- | Documentation/magic-number.txt | 6 | ||||
| -rw-r--r-- | Documentation/memory-hotplug.txt | 16 | ||||
| -rw-r--r-- | Documentation/mips/AU1xxx_IDE.README | 2 | ||||
| -rw-r--r-- | Documentation/powerpc/cpu_features.txt | 2 | ||||
| -rw-r--r-- | Documentation/s390/Debugging390.txt | 2 | ||||
| -rw-r--r-- | Documentation/s390/cds.txt | 2 | ||||
| -rw-r--r-- | Documentation/s390/s390dbf.txt | 2 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 3 | ||||
| -rw-r--r-- | Documentation/vm/unevictable-lru.txt | 63 | ||||
| -rw-r--r-- | Documentation/x86/zero-page.txt | 2 |
19 files changed, 189 insertions, 87 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 7a16fe1e2270..9fe91c02ee40 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -6,7 +6,6 @@ Description: internal state of the kernel memory blocks. Files could be added or removed dynamically to represent hot-add/remove operations. - Users: hotplug memory add/remove tools https://w3.opensource.ibm.com/projects/powerpc-utils/ @@ -19,6 +18,56 @@ Description: This is useful for a user-level agent to determine identify removable sections of the memory before attempting potentially expensive hot-remove memory operation +Users: hotplug memory remove tools + https://w3.opensource.ibm.com/projects/powerpc-utils/ + +What: /sys/devices/system/memory/memoryX/phys_device +Date: September 2008 +Contact: Badari Pulavarty <pbadari@us.ibm.com> +Description: + The file /sys/devices/system/memory/memoryX/phys_device + is read-only and is designed to show the name of physical + memory device. Implementation is currently incomplete. +What: /sys/devices/system/memory/memoryX/phys_index +Date: September 2008 +Contact: Badari Pulavarty <pbadari@us.ibm.com> +Description: + The file /sys/devices/system/memory/memoryX/phys_index + is read-only and contains the section ID in hexadecimal + which is equivalent to decimal X contained in the + memory section directory name. + +What: /sys/devices/system/memory/memoryX/state +Date: September 2008 +Contact: Badari Pulavarty <pbadari@us.ibm.com> +Description: + The file /sys/devices/system/memory/memoryX/state + is read-write. When read, it's contents show the + online/offline state of the memory section. When written, + root can toggle the the online/offline state of a removable + memory section (see removable file description above) + using the following commands. + # echo online > /sys/devices/system/memory/memoryX/state + # echo offline > /sys/devices/system/memory/memoryX/state + + For example, if /sys/devices/system/memory/memory22/removable + contains a value of 1 and + /sys/devices/system/memory/memory22/state contains the + string "online" the following command can be executed by + by root to offline that section. + # echo offline > /sys/devices/system/memory/memory22/state Users: hotplug memory remove tools https://w3.opensource.ibm.com/projects/powerpc-utils/ + +What: /sys/devices/system/node/nodeX/memoryY +Date: September 2008 +Contact: Gary Hade <garyhade@us.ibm.com> +Description: + When CONFIG_NUMA is enabled + /sys/devices/system/node/nodeX/memoryY is a symbolic link that + points to the corresponding /sys/devices/system/memory/memoryY + memory section directory. For example, the following symbolic + link is created for memory section 9 on node0. + /sys/devices/system/node/node0/memory9 -> ../../memory/memory9 + diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt index c74fec8c2351..b2a4d6d244d9 100644 --- a/Documentation/DMA-mapping.txt +++ b/Documentation/DMA-mapping.txt @@ -26,7 +26,7 @@ mapped only for the time they are actually used and unmapped after the DMA transfer. The following API will work of course even on platforms where no such -hardware exists, see e.g. include/asm-i386/pci.h for how it is implemented on +hardware exists, see e.g. arch/x86/include/asm/pci.h for how it is implemented on top of the virt_to_bus interface. First of all, you should make sure diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index ccec55394380..cfbfa15a46ba 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -397,7 +397,7 @@ prototypes: }; locking rules: - All except ->poll() may block. + All may block. BKL llseek: no (see below) read: no diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 71df353e367c..32e94635484f 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1385,6 +1385,15 @@ swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100 causes the kernel to prefer to reclaim dentries and inodes. +dirty_background_bytes +---------------------- + +Contains the amount of dirty memory at which the pdflush background writeback +daemon will start writeback. + +If dirty_background_bytes is written, dirty_background_ratio becomes a function +of its value (dirty_background_bytes / the amount of dirtyable system memory). + dirty_background_ratio ---------------------- @@ -1393,14 +1402,29 @@ pages + file cache, not including locked pages and HugePages), the number of pages at which the pdflush background writeback daemon will start writing out dirty data. +If dirty_background_ratio is written, dirty_background_bytes becomes a function +of its value (dirty_background_ratio * the amount of dirtyable system memory). + +dirty_bytes +----------- + +Contains the amount of dirty memory at which a process generating disk writes +will itself start writeback. + +If dirty_bytes is written, dirty_ratio becomes a function of its value +(dirty_bytes / the amount of dirtyable system memory). + dirty_ratio ------------------ +----------- Contains, as a percentage of the dirtyable system memory (free pages + mapped pages + file cache, not including locked pages and HugePages), the number of pages at which a process which is generating disk writes will itself start writing out dirty data. +If dirty_ratio is written, dirty_bytes becomes a function of its value +(dirty_ratio * the amount of dirtyable system memory). + dirty_writeback_centisecs ------------------------- diff --git a/Documentation/hwmon/adt7470 b/Documentation/hwmon/adt7470 index 75d13ca147cc..8ce4aa0a0f55 100644 --- a/Documentation/hwmon/adt7470 +++ b/Documentation/hwmon/adt7470 @@ -31,15 +31,11 @@ Each of the measured inputs (temperature, fan speed) has corresponding high/low limit values. The ADT7470 will signal an ALARM if any measured value exceeds either limit. -The ADT7470 DOES NOT sample all inputs continuously. A single pin on the -ADT7470 is connected to a multitude of thermal diodes, but the chip must be -instructed explicitly to read the multitude of diodes. If you want to use -automatic fan control mode, you must manually read any of the temperature -sensors or the fan control algorithm will not run. The chip WILL NOT DO THIS -AUTOMATICALLY; this must be done from userspace. This may be a bug in the chip -design, given that many other AD chips take care of this. The driver will not -read the registers more often than once every 5 seconds. Further, -configuration data is only read once per minute. +The ADT7470 samples all inputs continuously. A kernel thread is started up for +the purpose of periodically querying the temperature sensors, thus allowing the +automatic fan pwm control to set the fan speed. The driver will not read the +registers more often than once every 5 seconds. Further, configuration data is +only read once per minute. Special Features ---------------- @@ -72,5 +68,6 @@ pwm#_auto_point2_temp. Notes ----- -As stated above, the temperature inputs must be read periodically from -userspace in order for the automatic pwm algorithm to run. +The temperature inputs no longer need to be read periodically from userspace in +order for the automatic pwm algorithm to run. This was the case for earlier +versions of the driver. diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 824699174436..f1d639903325 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -84,7 +84,7 @@ Code Seq# Include File Comments 'B' C0-FF advanced bbus <mailto:maassen@uni-freiburg.de> 'C' all linux/soundcard.h -'D' all asm-s390/dasd.h +'D' all arch/s390/include/asm/dasd.h 'E' all linux/input.h 'F' all linux/fb.h 'H' all linux/hiddev.h @@ -105,7 +105,7 @@ Code Seq# Include File Comments 'S' 80-81 scsi/scsi_ioctl.h conflict! 'S' 82-FF scsi/scsi.h conflict! 'T' all linux/soundcard.h conflict! -'T' all asm-i386/ioctls.h conflict! +'T' all arch/x86/include/asm/ioctls.h conflict! 'U' 00-EF linux/drivers/usb/usb.h 'V' all linux/vt.h 'W' 00-1F linux/watchdog.h conflict! @@ -120,7 +120,7 @@ Code Seq# Include File Comments <mailto:natalia@nikhefk.nikhef.nl> 'c' 00-7F linux/comstats.h conflict! 'c' 00-7F linux/coda.h conflict! -'c' 80-9F asm-s390/chsc.h +'c' 80-9F arch/s390/include/asm/chsc.h 'd' 00-FF linux/char/drm/drm/h conflict! 'd' 00-DF linux/video_decoder.h conflict! 'd' F0-FF linux/digi1.h @@ -170,7 +170,7 @@ Code Seq# Include File Comments <mailto:oe@port.de> 0x80 00-1F linux/fb.h 0x81 00-1F linux/videotext.h -0x89 00-06 asm-i386/sockios.h +0x89 00-06 arch/x86/include/asm/sockios.h 0x89 0B-DF linux/sockios.h 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range diff --git a/Documentation/kernel-doc-nano-HOWTO.txt b/Documentation/kernel-doc-nano-HOWTO.txt index c6841eee9598..d73fbd2b2b45 100644 --- a/Documentation/kernel-doc-nano-HOWTO.txt +++ b/Documentation/kernel-doc-nano-HOWTO.txt @@ -71,6 +71,11 @@ The @argument descriptions must begin on the very next line following this opening short function description line, with no intervening empty comment lines. +If a function parameter is "..." (varargs), it should be listed in +kernel-doc notation as: + * @...: description + + Example kernel-doc data structure comment. /** @@ -282,6 +287,32 @@ struct my_struct { }; +Including documentation blocks in source files +---------------------------------------------- + +To facilitate having source code and comments close together, you can +include kernel-doc documentation blocks that are free-form comments +instead of being kernel-doc for functions, structures, unions, +enums, or typedefs. This could be used for something like a +theory of operation for a driver or library code, for example. + +This is done by using a DOC: section keyword with a section title. E.g.: + +/** + * DOC: Theory of Operation + * + * The whizbang foobar is a dilly of a gizmo. It can do whatever you + * want it to do, at any time. It reads your mind. Here's how it works. + * + * foo bar splat + * + * The only drawback to this gizmo is that is can sometimes damage + * hardware, software, or its subject(s). + */ + +DOC: sections are used in SGML templates files as indicated below. + + How to make new SGML template files ----------------------------------- @@ -302,6 +333,9 @@ exported using EXPORT_SYMBOL. !F<filename> <function [functions...]> is replaced by the documentation, in <filename>, for the functions listed. +!P<filename> <section title> is replaced by the contents of the DOC: +section titled <section title> from <filename>. +Spaces are allowed in <section title>; do not quote the <section title>. Tim. */ <twaugh@redhat.com> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a2d8805c03d5..0b3f6711d2f1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -469,8 +469,8 @@ and is between 256 and 4096 characters. It is defined in the file clearcpuid=BITNUM [X86] Disable CPUID feature X for the kernel. See - include/asm-x86/cpufeature.h for the valid bit numbers. - Note the Linux specific bits are not necessarily + arch/x86/include/asm/cpufeature.h for the valid bit + numbers. Note the Linux specific bits are not necessarily stable over kernel options, but the vendor specific ones should be. Also note that user programs calling CPUID directly @@ -551,6 +551,11 @@ and is between 256 and 4096 characters. It is defined in the file not work reliably with all consoles, but is known to work with serial and VGA consoles. + coredump_filter= + [KNL] Change the default value for + /proc/<pid>/coredump_filter. + See also Documentation/filesystems/proc.txt. + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] @@ -1117,6 +1122,8 @@ and is between 256 and 4096 characters. It is defined in the file If there are multiple matching configurations changing the same attribute, the last one is used. + lmb=debug [KNL] Enable lmb debug messages. + load_ramdisk= [RAM] List of ramdisks to load from floppy See Documentation/blockdev/ramdisk.txt. @@ -1569,6 +1576,10 @@ and is between 256 and 4096 characters. It is defined in the file nr_uarts= [SERIAL] maximum number of UARTs to be registered. + ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. + See Documentation/debugging-via-ohci1394.txt for more + info. + olpc_ec_timeout= [OLPC] ms delay when issuing EC commands Rather than timing out after 20 ms if an EC command is not properly ACKed, override the length @@ -1793,10 +1804,10 @@ and is between 256 and 4096 characters. It is defined in the file autoconfiguration. Ranges are in pairs (memory base and size). - dynamic_printk - Enables pr_debug()/dev_dbg() calls if - CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. These can also - be switched on/off via <debugfs>/dynamic_printk/modules + dynamic_printk Enables pr_debug()/dev_dbg() calls if + CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. + These can also be switched on/off via + <debugfs>/dynamic_printk/modules print-fatal-signals= [KNL] debug: print fatal signals @@ -1884,7 +1895,7 @@ and is between 256 and 4096 characters. It is defined in the file reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode Format: <reboot_mode>[,<reboot_mode2>[,...]] - See arch/*/kernel/reboot.c or arch/*/kernel/process.c + See arch/*/kernel/reboot.c or arch/*/kernel/process.c relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. @@ -2432,8 +2443,8 @@ and is between 256 and 4096 characters. It is defined in the file Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] - norandmaps Don't use address space randomization - Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space + norandmaps Don't use address space randomization. Equivalent to + echo 0 > /proc/sys/kernel/randomize_va_space ______________________________________________________________________ diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index a79633d702bf..48b3de90eb1e 100644 --- a/Documentation/kprobes.txt +++ b/Documentation/kprobes.txt @@ -497,7 +497,10 @@ The first column provides the kernel address where the probe is inserted. The second column identifies the type of probe (k - kprobe, r - kretprobe and j - jprobe), while the third column specifies the symbol+offset of the probe. If the probed function belongs to a module, the module name -is also specified. +is also specified. Following columns show probe status. If the probe is on +a virtual address that is no longer valid (module init sections, module +virtual addresses that correspond to modules that've been unloaded), +such probes are marked with [GONE]. /debug/kprobes/enabled: Turn kprobes ON/OFF diff --git a/Documentation/magic-number.txt b/Documentation/magic-number.txt index 95070028d15e..505f19607542 100644 --- a/Documentation/magic-number.txt +++ b/Documentation/magic-number.txt @@ -125,14 +125,14 @@ TRIDENT_CARD_MAGIC 0x5072696E trident_card sound/oss/trident.c ROUTER_MAGIC 0x524d4157 wan_device include/linux/wanrouter.h SCC_MAGIC 0x52696368 gs_port drivers/char/scc.h SAVEKMSG_MAGIC1 0x53415645 savekmsg arch/*/amiga/config.c -GDA_MAGIC 0x58464552 gda include/asm-mips64/sn/gda.h +GDA_MAGIC 0x58464552 gda arch/mips/include/asm/sn/gda.h RED_MAGIC1 0x5a2cf071 (any) mm/slab.c STL_PORTMAGIC 0x5a7182c9 stlport include/linux/stallion.h EEPROM_MAGIC_VALUE 0x5ab478d2 lanai_dev drivers/atm/lanai.c HDLCDRV_MAGIC 0x5ac6e778 hdlcdrv_state include/linux/hdlcdrv.h EPCA_MAGIC 0x5c6df104 channel include/linux/epca.h PCXX_MAGIC 0x5c6df104 channel drivers/char/pcxx.h -KV_MAGIC 0x5f4b565f kernel_vars_s include/asm-mips64/sn/klkernvars.h +KV_MAGIC 0x5f4b565f kernel_vars_s arch/mips/include/asm/sn/klkernvars.h I810_STATE_MAGIC 0x63657373 i810_state sound/oss/i810_audio.c TRIDENT_STATE_MAGIC 0x63657373 trient_state sound/oss/trident.c M3_CARD_MAGIC 0x646e6f50 m3_card sound/oss/maestro3.c @@ -158,7 +158,7 @@ CCB_MAGIC 0xf2691ad2 ccb drivers/scsi/ncr53c8xx.c QUEUE_MAGIC_FREE 0xf7e1c9a3 queue_entry drivers/scsi/arm/queue.c QUEUE_MAGIC_USED 0xf7e1cc33 queue_entry drivers/scsi/arm/queue.c HTB_CMAGIC 0xFEFAFEF1 htb_class net/sched/sch_htb.c -NMI_MAGIC 0x48414d4d455201 nmi_s include/asm-mips64/sn/nmi.h +NMI_MAGIC 0x48414d4d455201 nmi_s arch/mips/include/asm/sn/nmi.h Note that there are also defined special per-driver magic numbers in sound memory management. See include/sound/sndmagic.h for complete list of them. Many diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 168117bd6ee8..4c2ecf537a4a 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -124,7 +124,7 @@ config options. This option can be kernel module too. -------------------------------- -3 sysfs files for memory hotplug +4 sysfs files for memory hotplug -------------------------------- All sections have their device information under /sys/devices/system/memory as @@ -138,11 +138,12 @@ For example, assume 1GiB section size. A device for a memory starting at (0x100000000 / 1Gib = 4) This device covers address range [0x100000000 ... 0x140000000) -Under each section, you can see 3 files. +Under each section, you can see 4 files. /sys/devices/system/memory/memoryXXX/phys_index /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state +/sys/devices/system/memory/memoryXXX/removable 'phys_index' : read-only and contains section id, same as XXX. 'state' : read-write @@ -150,10 +151,20 @@ Under each section, you can see 3 files. at write: user can specify "online", "offline" command 'phys_device': read-only: designed to show the name of physical memory device. This is not well implemented now. +'removable' : read-only: contains an integer value indicating + whether the memory section is removable or not + removable. A value of 1 indicates that the memory + section is removable and a value of 0 indicates that + it is not removable. NOTE: These directories/files appear after physical memory hotplug phase. +If CONFIG_NUMA is enabled the +/sys/devices/system/memory/memoryXXX memory section +directories can also be accessed via symbolic links located in +the /sys/devices/system/node/node* directories. For example: +/sys/devices/system/node/node0/memory9 -> ../../memory/memory9 -------------------------------- 4. Physical memory hot-add phase @@ -365,7 +376,6 @@ node if necessary. - allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like sysctl or new control file. - showing memory section and physical device relationship. - - showing memory section and node relationship (maybe good for NUMA) - showing memory section is under ZONE_MOVABLE or not - test and make it better memory offlining. - support HugeTLB page migration and offlining. diff --git a/Documentation/mips/AU1xxx_IDE.README b/Documentation/mips/AU1xxx_IDE.README index 25a6ed1aaa5b..f54962aea84d 100644 --- a/Documentation/mips/AU1xxx_IDE.README +++ b/Documentation/mips/AU1xxx_IDE.README @@ -44,7 +44,7 @@ FILES, CONFIGS AND COMPATABILITY Two files are introduced: - a) 'include/asm-mips/mach-au1x00/au1xxx_ide.h' + a) 'arch/mips/include/asm/mach-au1x00/au1xxx_ide.h' containes : struct _auide_hwif timing parameters for PIO mode 0/1/2/3/4 timing parameters for MWDMA 0/1/2 diff --git a/Documentation/powerpc/cpu_features.txt b/Documentation/powerpc/cpu_features.txt index 472739880e87..ffa4183fdb8b 100644 --- a/Documentation/powerpc/cpu_features.txt +++ b/Documentation/powerpc/cpu_features.txt @@ -31,7 +31,7 @@ anyways). After detecting the processor type, the kernel patches out sections of code that shouldn't be used by writing nop's over it. Using cpufeatures requires -just 2 macros (found in include/asm-ppc/cputable.h), as seen in head.S +just 2 macros (found in arch/powerpc/include/asm/cputable.h), as seen in head.S transfer_to_handler: #ifdef CONFIG_ALTIVEC diff --git a/Documentation/s390/Debugging390.txt b/Documentation/s390/Debugging390.txt index d30a281c570f..10711d9f0788 100644 --- a/Documentation/s390/Debugging390.txt +++ b/Documentation/s390/Debugging390.txt @@ -1402,7 +1402,7 @@ Syscalls are implemented on Linux for S390 by the Supervisor call instruction (S possibilities of these as the instruction is made up of a 0xA opcode & the second byte being the syscall number. They are traced using the simple command. TR SVC <Optional value or range> -the syscalls are defined in linux/include/asm-s390/unistd.h +the syscalls are defined in linux/arch/s390/include/asm/unistd.h e.g. to trace all file opens just do TR SVC 5 ( as this is the syscall number of open ) diff --git a/Documentation/s390/cds.txt b/Documentation/s390/cds.txt index c4b7b2bd369a..480a78ef5a1e 100644 --- a/Documentation/s390/cds.txt +++ b/Documentation/s390/cds.txt @@ -98,7 +98,7 @@ platform. Some of the interface routines are specific to Linux/390 and some of them can be found on other Linux platforms implementations too. Miscellaneous function prototypes, data declarations, and macro definitions can be found in the architecture specific C header file -linux/include/asm-s390/irq.h. +linux/arch/s390/include/asm/irq.h. Overview of CDS interface concepts diff --git a/Documentation/s390/s390dbf.txt b/Documentation/s390/s390dbf.txt index e05420973698..2d10053dd97e 100644 --- a/Documentation/s390/s390dbf.txt +++ b/Documentation/s390/s390dbf.txt @@ -2,7 +2,7 @@ S390 Debug Feature ================== files: arch/s390/kernel/debug.c - include/asm-s390/debug.h + arch/s390/include/asm/debug.h Description: ------------ diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index d79eeda7a699..cd05994a49e6 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -41,7 +41,8 @@ Currently, these files are in /proc/sys/vm: ============================================================== -dirty_ratio, dirty_background_ratio, dirty_expire_centisecs, +dirty_bytes, dirty_ratio, dirty_background_bytes, +dirty_background_ratio, dirty_expire_centisecs, dirty_writeback_centisecs, highmem_is_dirtyable, vfs_cache_pressure, laptop_mode, block_dump, swap_token_timeout, drop-caches, hugepages_treat_as_movable: diff --git a/Documentation/vm/unevictable-lru.txt b/Documentation/vm/unevictable-lru.txt index 125eed560e5a..0706a7282a8c 100644 --- a/Documentation/vm/unevictable-lru.txt +++ b/Documentation/vm/unevictable-lru.txt @@ -137,13 +137,6 @@ shrink_page_list() where they will be detected when vmscan walks the reverse map in try_to_unmap(). If try_to_unmap() returns SWAP_MLOCK, shrink_page_list() will cull the page at that point. -Note that for anonymous pages, shrink_page_list() attempts to add the page to -the swap cache before it tries to unmap the page. To avoid this unnecessary -consumption of swap space, shrink_page_list() calls try_to_munlock() to check -whether any VM_LOCKED vmas map the page without attempting to unmap the page. -If try_to_munlock() returns SWAP_MLOCK, shrink_page_list() will cull the page -without consuming swap space. try_to_munlock() will be described below. - To "cull" an unevictable page, vmscan simply puts the page back on the lru list using putback_lru_page()--the inverse operation to isolate_lru_page()-- after dropping the page lock. Because the condition which makes the page @@ -190,8 +183,8 @@ several places: in the VM_LOCKED flag being set for the vma. 3) in the fault path, if mlocked pages are "culled" in the fault path, and when a VM_LOCKED stack segment is expanded. -4) as mentioned above, in vmscan:shrink_page_list() with attempting to - reclaim a page in a VM_LOCKED vma--via try_to_unmap() or try_to_munlock(). +4) as mentioned above, in vmscan:shrink_page_list() when attempting to + reclaim a page in a VM_LOCKED vma via try_to_unmap(). Mlocked pages become unlocked and rescued from the unevictable list when: @@ -260,9 +253,9 @@ mlock_fixup() filters several classes of "special" vmas: 2) vmas mapping hugetlbfs page are already effectively pinned into memory. We don't need nor want to mlock() these pages. However, to preserve the - prior behavior of mlock()--before the unevictable/mlock changes--mlock_fixup() - will call make_pages_present() in the hugetlbfs vma range to allocate the - huge pages and populate the ptes. + prior behavior of mlock()--before the unevictable/mlock changes-- + mlock_fixup() will call make_pages_present() in the hugetlbfs vma range + to allocate the huge pages and populate the ptes. 3) vmas with VM_DONTEXPAND|VM_RESERVED are generally user space mappings of kernel pages, such as the vdso page, relay channel pages, etc. These pages @@ -322,7 +315,7 @@ __mlock_vma_pages_range()--the same function used to mlock a vma range-- passing a flag to indicate that munlock() is being performed. Because the vma access protections could have been changed to PROT_NONE after -faulting in and mlocking some pages, get_user_pages() was unreliable for visiting +faulting in and mlocking pages, get_user_pages() was unreliable for visiting these pages for munlocking. Because we don't want to leave pages mlocked(), get_user_pages() was enhanced to accept a flag to ignore the permissions when fetching the pages--all of which should be resident as a result of previous @@ -416,8 +409,8 @@ Mlocked Pages: munmap()/exit()/exec() System Call Handling When unmapping an mlocked region of memory, whether by an explicit call to munmap() or via an internal unmap from exit() or exec() processing, we must munlock the pages if we're removing the last VM_LOCKED vma that maps the pages. -Before the unevictable/mlock changes, mlocking did not mark the pages in any way, -so unmapping them required no processing. +Before the unevictable/mlock changes, mlocking did not mark the pages in any +way, so unmapping them required no processing. To munlock a range of memory under the unevictable/mlock infrastructure, the munmap() hander and task address space tear down function call @@ -517,12 +510,10 @@ couldn't be mlocked. Mlocked pages: try_to_munlock() Reverse Map Scan TODO/FIXME: a better name might be page_mlocked()--analogous to the -page_referenced() reverse map walker--especially if we continue to call this -from shrink_page_list(). See related TODO/FIXME below. +page_referenced() reverse map walker. -When munlock_vma_page()--see "Mlocked Pages: munlock()/munlockall() System -Call Handling" above--tries to munlock a page, or when shrink_page_list() -encounters an anonymous page that is not yet in the swap cache, they need to +When munlock_vma_page()--see "Mlocked Pages: munlock()/munlockall() +System Call Handling" above--tries to munlock a page, it needs to determine whether or not the page is mapped by any VM_LOCKED vma, without actually attempting to unmap all ptes from the page. For this purpose, the unevictable/mlock infrastructure introduced a variant of try_to_unmap() called @@ -535,10 +526,7 @@ for VM_LOCKED vmas. When such a vma is found for anonymous pages and file pages mapped in linear VMAs, as in the try_to_unmap() case, the functions attempt to acquire the associated mmap semphore, mlock the page via mlock_vma_page() and return SWAP_MLOCK. This effectively undoes the -pre-clearing of the page's PG_mlocked done by munlock_vma_page() and informs -shrink_page_list() that the anonymous page should be culled rather than added -to the swap cache in preparation for a try_to_unmap() that will almost -certainly fail. +pre-clearing of the page's PG_mlocked done by munlock_vma_page. If try_to_unmap() is unable to acquire a VM_LOCKED vma's associated mmap semaphore, it will return SWAP_AGAIN. This will allow shrink_page_list() @@ -557,10 +545,7 @@ However, the scan can terminate when it encounters a VM_LOCKED vma and can successfully acquire the vma's mmap semphore for read and mlock the page. Although try_to_munlock() can be called many [very many!] times when munlock()ing a large region or tearing down a large address space that has been -mlocked via mlockall(), overall this is a fairly rare event. In addition, -although shrink_page_list() calls try_to_munlock() for every anonymous page that -it handles that is not yet in the swap cache, on average anonymous pages will -have very short reverse map lists. +mlocked via mlockall(), overall this is a fairly rare event. Mlocked Page: Page Reclaim in shrink_*_list() @@ -588,8 +573,8 @@ Some examples of these unevictable pages on the LRU lists are: munlock_vma_page() was forced to let the page back on to the normal LRU list for vmscan to handle. -shrink_inactive_list() also culls any unevictable pages that it finds -on the inactive lists, again diverting them to the appropriate zone's unevictable +shrink_inactive_list() also culls any unevictable pages that it finds on +the inactive lists, again diverting them to the appropriate zone's unevictable lru list. shrink_inactive_list() should only see SHM_LOCKed pages that became SHM_LOCKed after shrink_active_list() had moved them to the inactive list, or pages mapped into VM_LOCKED vmas that munlock_vma_page() couldn't isolate from @@ -597,19 +582,7 @@ the lru to recheck via try_to_munlock(). shrink_inactive_list() won't notice the latter, but will pass on to shrink_page_list(). shrink_page_list() again culls obviously unevictable pages that it could -encounter for similar reason to shrink_inactive_list(). As already discussed, -shrink_page_list() proactively looks for anonymous pages that should have -PG_mlocked set but don't--these would not be detected by page_evictable()--to -avoid adding them to the swap cache unnecessarily. File pages mapped into +encounter for similar reason to shrink_inactive_list(). Pages mapped into VM_LOCKED vmas but without PG_mlocked set will make it all the way to -try_to_unmap(). shrink_page_list() will divert them to the unevictable list when -try_to_unmap() returns SWAP_MLOCK, as discussed above. - -TODO/FIXME: If we can enhance the swap cache to reliably remove entries -with page_count(page) > 2, as long as all ptes are mapped to the page and -not the swap entry, we can probably remove the call to try_to_munlock() in -shrink_page_list() and just remove the page from the swap cache when -try_to_unmap() returns SWAP_MLOCK. Currently, remove_exclusive_swap_page() -doesn't seem to allow that. - - +try_to_unmap(). shrink_page_list() will divert them to the unevictable list +when try_to_unmap() returns SWAP_MLOCK, as discussed above. diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt index 169ad423a3d1..4f913857b8a2 100644 --- a/Documentation/x86/zero-page.txt +++ b/Documentation/x86/zero-page.txt @@ -3,7 +3,7 @@ protocol of kernel. These should be filled by bootloader or 16-bit real-mode setup code of the kernel. References/settings to it mainly are in: - include/asm-x86/bootparam.h + arch/x86/include/asm/bootparam.h Offset Proto Name Meaning |
