diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 72 | ||||
| -rw-r--r-- | Documentation/blockdev/zram.txt | 25 | ||||
| -rw-r--r-- | Documentation/features/vm/pte_special/arch-support.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/00-INDEX | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/autofs-mount-control.txt (renamed from Documentation/filesystems/autofs4-mount-control.txt) | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/autofs.txt (renamed from Documentation/filesystems/autofs4.txt) | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/automount-support.txt | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/path-lookup.md | 2 |
8 files changed, 96 insertions, 30 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 74cdeaed9f7a..8a2c52d5c53b 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1001,14 +1001,44 @@ PAGE_SIZE multiple when read back. The total amount of memory currently being used by the cgroup and its descendants. + memory.min + A read-write single value file which exists on non-root + cgroups. The default is "0". + + Hard memory protection. If the memory usage of a cgroup + is within its effective min boundary, the cgroup's memory + won't be reclaimed under any conditions. If there is no + unprotected reclaimable memory available, OOM killer + is invoked. + + Effective min boundary is limited by memory.min values of + all ancestor cgroups. If there is memory.min overcommitment + (child cgroup or cgroups are requiring more protected memory + than parent will allow), then each child cgroup will get + the part of parent's protection proportional to its + actual memory usage below memory.min. + + Putting more memory than generally available under this + protection is discouraged and may lead to constant OOMs. + + If a memory cgroup is not populated with processes, + its memory.min is ignored. + memory.low A read-write single value file which exists on non-root cgroups. The default is "0". - Best-effort memory protection. If the memory usages of a - cgroup and all its ancestors are below their low boundaries, - the cgroup's memory won't be reclaimed unless memory can be - reclaimed from unprotected cgroups. + Best-effort memory protection. If the memory usage of a + cgroup is within its effective low boundary, the cgroup's + memory won't be reclaimed unless memory can be reclaimed + from unprotected cgroups. + + Effective low boundary is limited by memory.low values of + all ancestor cgroups. If there is memory.low overcommitment + (child cgroup or cgroups are requiring more protected memory + than parent will allow), then each child cgroup will get + the part of parent's protection proportional to its + actual memory usage below memory.low. Putting more memory than generally available under this protection is discouraged. @@ -1199,6 +1229,27 @@ PAGE_SIZE multiple when read back. Swap usage hard limit. If a cgroup's swap usage reaches this limit, anonymous memory of the cgroup will not be swapped out. + memory.swap.events + A read-only flat-keyed file which exists on non-root cgroups. + The following entries are defined. Unless specified + otherwise, a value change in this file generates a file + modified event. + + max + The number of times the cgroup's swap usage was about + to go over the max boundary and swap allocation + failed. + + fail + The number of times swap allocation failed either + because of running out of swap system-wide or max + limit. + + When reduced under the current usage, the existing swap + entries are reclaimed gradually and the swap usage may stay + higher than the limit for an extended period of time. This + reduces the impact on the workload and memory management. + Usage Guidelines ~~~~~~~~~~~~~~~~ @@ -1934,17 +1985,8 @@ system performance due to overreclaim, to the point where the feature becomes self-defeating. The memory.low boundary on the other hand is a top-down allocated -reserve. A cgroup enjoys reclaim protection when it and all its -ancestors are below their low boundaries, which makes delegation of -subtrees possible. Secondly, new cgroups have no reserve per default -and in the common case most cgroups are eligible for the preferred -reclaim pass. This allows the new low boundary to be efficiently -implemented with just a minor addition to the generic reclaim code, -without the need for out-of-band data structures and reclaim passes. -Because the generic reclaim code considers all cgroups except for the -ones running low in the preferred first reclaim pass, overreclaim of -individual groups is eliminated as well, resulting in much better -overall workload performance. +reserve. A cgroup enjoys reclaim protection when it's within its low, +which makes delegation of subtrees possible. The original high boundary, the hard limit, is defined as a strict limit that can not budge, even if the OOM killer has to be called. diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 257e65714c6a..875b2b56b87f 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -218,6 +218,7 @@ line of text and contains the following stats separated by whitespace: same_pages the number of same element filled pages written to this disk. No memory is allocated for such pages. pages_compacted the number of pages freed during compaction + huge_pages the number of incompressible pages 9) Deactivate: swapoff /dev/zram0 @@ -242,5 +243,29 @@ to backing storage rather than keeping it in memory. User should set up backing device via /sys/block/zramX/backing_dev before disksize setting. += memory tracking + +With CONFIG_ZRAM_MEMORY_TRACKING, user can know information of the +zram block. It could be useful to catch cold or incompressible +pages of the process with*pagemap. +If you enable the feature, you could see block state via +/sys/kernel/debug/zram/zram0/block_state". The output is as follows, + + 300 75.033841 .wh + 301 63.806904 s.. + 302 63.806919 ..h + +First column is zram's block index. +Second column is access time since the system was booted +Third column is state of the block. +(s: same page +w: written page to backing store +h: huge page) + +First line of above example says 300th block is accessed at 75.033841sec +and the block's state is huge so it is written back to the backing +storage. It's a debugging feature so anyone shouldn't rely on it to work +properly. + Nitin Gupta ngupta@vflare.org diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt index 6a608a6dcf71..a8378424bc98 100644 --- a/Documentation/features/vm/pte_special/arch-support.txt +++ b/Documentation/features/vm/pte_special/arch-support.txt @@ -1,6 +1,6 @@ # # Feature name: pte_special -# Kconfig: __HAVE_ARCH_PTE_SPECIAL +# Kconfig: ARCH_HAS_PTE_SPECIAL # description: arch supports the pte_special()/pte_mkspecial() VM APIs # ----------------------- diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index b7bd6c9009cc..a8bd4af7fbce 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX @@ -10,8 +10,8 @@ afs.txt - info and examples for the distributed AFS (Andrew File System) fs. affs.txt - info and mount options for the Amiga Fast File System. -autofs4-mount-control.txt - - info on device control operations for autofs4 module. +autofs-mount-control.txt + - info on device control operations for autofs module. automount-support.txt - information about filesystem automount support. befs.txt diff --git a/Documentation/filesystems/autofs4-mount-control.txt b/Documentation/filesystems/autofs-mount-control.txt index e5177cb31a04..45edad6933cc 100644 --- a/Documentation/filesystems/autofs4-mount-control.txt +++ b/Documentation/filesystems/autofs-mount-control.txt @@ -1,5 +1,5 @@ -Miscellaneous Device control operations for the autofs4 kernel module +Miscellaneous Device control operations for the autofs kernel module ==================================================================== The problem @@ -164,7 +164,7 @@ possibility for future development due to the requirements of the message bus architecture. -autofs4 Miscellaneous Device mount control interface +autofs Miscellaneous Device mount control interface ==================================================== The control interface is opening a device node, typically /dev/autofs. @@ -244,7 +244,7 @@ The device node ioctl operations implemented by this interface are: AUTOFS_DEV_IOCTL_VERSION ------------------------ -Get the major and minor version of the autofs4 device ioctl kernel module +Get the major and minor version of the autofs device ioctl kernel module implementation. It requires an initialized struct autofs_dev_ioctl as an input parameter and sets the version information in the passed in structure. It returns 0 on success or the error -EINVAL if a version mismatch is @@ -254,7 +254,7 @@ detected. AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD ------------------------------------------------------------------ -Get the major and minor version of the autofs4 protocol version understood +Get the major and minor version of the autofs protocol version understood by loaded module. This call requires an initialized struct autofs_dev_ioctl with the ioctlfd field set to a valid autofs mount point descriptor and sets the requested version number in version field of struct args_protover @@ -404,4 +404,3 @@ type is also given we are looking for a particular autofs mount and if a match isn't found a fail is returned. If the the located path is the root of a mount 1 is returned along with the super magic of the mount or 0 otherwise. - diff --git a/Documentation/filesystems/autofs4.txt b/Documentation/filesystems/autofs.txt index f10dd590f69f..373ad25852d3 100644 --- a/Documentation/filesystems/autofs4.txt +++ b/Documentation/filesystems/autofs.txt @@ -30,15 +30,15 @@ key advantages: Context ------- -The "autofs4" filesystem module is only one part of an autofs system. +The "autofs" filesystem module is only one part of an autofs system. There also needs to be a user-space program which looks up names and mounts filesystems. This will often be the "automount" program, -though other tools including "systemd" can make use of "autofs4". +though other tools including "systemd" can make use of "autofs". This document describes only the kernel module and the interactions required with any user-space program. Subsequent text refers to this as the "automount daemon" or simply "the daemon". -"autofs4" is a Linux kernel module with provides the "autofs" +"autofs" is a Linux kernel module with provides the "autofs" filesystem type. Several "autofs" filesystems can be mounted and they can each be managed separately, or all managed by the same daemon. @@ -215,7 +215,7 @@ of expiry. The VFS also supports "expiry" of mounts using the MNT_EXPIRE flag to the `umount` system call. Unmounting with MNT_EXPIRE will fail unless a previous attempt had been made, and the filesystem has been inactive -and untouched since that previous attempt. autofs4 does not depend on +and untouched since that previous attempt. autofs does not depend on this but has its own internal tracking of whether filesystems were recently used. This allows individual names in the autofs directory to expire separately. @@ -415,7 +415,7 @@ which can be used to communicate directly with the autofs filesystem. It requires CAP_SYS_ADMIN for access. The `ioctl`s that can be used on this device are described in a separate -document `autofs4-mount-control.txt`, and are summarized briefly here. +document `autofs-mount-control.txt`, and are summarized briefly here. Each ioctl is passed a pointer to an `autofs_dev_ioctl` structure: struct autofs_dev_ioctl { diff --git a/Documentation/filesystems/automount-support.txt b/Documentation/filesystems/automount-support.txt index 7eb762eb3136..b0afd3d55eaf 100644 --- a/Documentation/filesystems/automount-support.txt +++ b/Documentation/filesystems/automount-support.txt @@ -9,7 +9,7 @@ also be requested by userspace. IN-KERNEL AUTOMOUNTING ====================== -See section "Mount Traps" of Documentation/filesystems/autofs4.txt +See section "Mount Traps" of Documentation/filesystems/autofs.txt Then from userspace, you can just do something like: diff --git a/Documentation/filesystems/path-lookup.md b/Documentation/filesystems/path-lookup.md index 1933ef734e63..e2edd45c4bc0 100644 --- a/Documentation/filesystems/path-lookup.md +++ b/Documentation/filesystems/path-lookup.md @@ -460,7 +460,7 @@ this retry process in the next article. Automount points are locations in the filesystem where an attempt to lookup a name can trigger changes to how that lookup should be handled, in particular by mounting a filesystem there. These are -covered in greater detail in autofs4.txt in the Linux documentation +covered in greater detail in autofs.txt in the Linux documentation tree, but a few notes specifically related to path lookup are in order here. |