linux-stable/Documentation/filesystems
Stefan Roesch 8b47933544 proc/ksm: add ksm stats to /proc/pid/smaps
With madvise and prctl KSM can be enabled for different VMA's.  Once it is
enabled we can query how effective KSM is overall.  However we cannot
easily query if an individual VMA benefits from KSM.

This commit adds a KSM section to the /prod/<pid>/smaps file.  It reports
how many of the pages are KSM pages.  Note that KSM-placed zeropages are
not included, only actual KSM pages.

Here is a typical output:

7f420a000000-7f421a000000 rw-p 00000000 00:00 0
Size:             262144 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Rss:               51212 kB
Pss:                8276 kB
Shared_Clean:        172 kB
Shared_Dirty:      42996 kB
Private_Clean:       196 kB
Private_Dirty:      7848 kB
Referenced:        15388 kB
Anonymous:         51212 kB
KSM:               41376 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:         0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:             202016 kB
SwapPss:            3882 kB
Locked:                0 kB
THPeligible:    0
ProtectionKey:         0
ksm_state:          0
ksm_skip_base:      0
ksm_skip_count:     0
VmFlags: rd wr mr mw me nr mg anon

This information also helps with the following workflow:
- First enable KSM for all the VMA's of a process with prctl.
- Then analyze with the above smaps report which VMA's benefit the most
- Change the application (if possible) to add the corresponding madvise
calls for the VMA's that benefit the most

[shr@devkernel.io: v5]
  Link: https://lkml.kernel.org/r/20230823170107.1457915-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20230822180539.1424843-1-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-02 15:17:33 -07:00
..
caching Remove duplicate words inside documentation 2022-09-27 13:21:43 -06:00
ext4 ext4: update doc about journal superblock description 2023-06-26 19:35:13 -04:00
nfs exportfs: add explicit flag to request non-decodeable file handles 2023-05-22 18:08:37 +02:00
smb smb3: move Documentation/filesystems/cifs to Documentation/filesystems/smb 2023-05-24 16:29:21 -05:00
spufs Documentation: spufs: correct a duplicate word typo 2022-09-27 13:21:44 -06:00
9p.rst fs/9p: Rework cache modes and add new options to Documentation 2023-04-09 21:41:21 +00:00
adfs.rst docs: filesystems: convert adfs.txt to ReST 2020-03-02 13:58:44 -07:00
affs.rst affs: fix basic permission bits to actually work 2020-08-31 12:20:31 +02:00
afs.rst AFS: Documentation: fix a few typos in afs.rst 2021-01-21 14:06:00 -07:00
api-summary.rst block: move fs/block_dev.c to block/bdev.c 2021-09-07 08:39:40 -06:00
autofs-mount-control.rst autofs: use flexible array in ioctl structure 2023-05-30 16:42:00 -07:00
autofs.rst autofs: use flexible array in ioctl structure 2023-05-30 16:42:00 -07:00
automount-support.rst docs: filesystems: convert automount-support.txt to ReST 2020-05-05 09:22:21 -06:00
befs.rst docs: filesystems: convert befs.txt to ReST 2020-03-02 14:01:25 -07:00
bfs.rst docs: filesystems: convert bfs.txt to ReST 2020-03-02 14:01:26 -07:00
btrfs.rst Documentation: update btrfs list of features and link to readthedocs.io 2022-06-21 14:47:19 +02:00
ceph.rst ceph: remove Sage's git tree from documentation 2022-10-04 19:18:08 +02:00
coda.rst Documentation: coda: annotate duplicated words 2020-07-13 10:02:32 -06:00
configfs.rst configfs: remove mentions of committable items 2022-12-02 11:11:27 +01:00
cramfs.rst docs: filesystems: convert cramfs.txt to ReST 2020-03-02 14:02:07 -07:00
dax.rst Documentation/filesystem/dax: update DAX description on erofs 2022-03-16 09:38:38 +08:00
debugfs.rst debugfs: small Documentation cleaning 2022-11-09 13:58:55 -07:00
devpts.rst docs: filesystems: convert devpts.txt to ReST 2020-05-05 09:22:21 -06:00
directory-locking.rst fs: Lock moved directories 2023-06-02 15:00:18 +02:00
dlmfs.rst docs: update ocfs2-devel mailing list address 2023-07-08 09:29:29 -07:00
dnotify.rst docs: filesystems: convert dnotify.txt to ReST 2020-05-05 09:22:22 -06:00
ecryptfs.rst docs: prevent warnings due to autosectionlabel 2020-03-20 17:01:29 -06:00
efivarfs.rst docs: filesystems: add info about efivars content 2020-05-25 18:59:59 -06:00
erofs.rst erofs: set block size to the on-disk block size 2023-04-17 01:15:45 +08:00
ext2.rst ext2: remove nobh support 2022-08-02 12:34:04 -04:00
ext3.rst docs: filesystems: convert ext3.txt to ReST 2020-03-02 14:03:16 -07:00
f2fs.rst f2fs: support errors=remount-ro|continue|panic mountoption 2023-05-08 11:18:04 -07:00
fiemap.rst A lot of bug fixes and cleanups for ext4, including: 2020-06-05 16:19:28 -07:00
files.rst file: Rename fcheck lookup_fd_rcu 2020-12-10 12:40:07 -06:00
fscrypt.rst fscrypt: support decrypting data from large folios 2023-01-28 15:10:12 -08:00
fsverity.rst fsverity: improve documentation for builtin signature support 2023-06-20 22:47:55 -07:00
fuse-io.rst docs: filesystems: convert fuse-io.txt to ReST 2020-05-05 09:22:22 -06:00
fuse.rst fuse: Add module param for CAP_SYS_ADMIN access bypassing allow_other 2022-07-21 16:06:19 +02:00
gfs2-glocks.rst docs: filesystems: convert gfs2-glocks.txt to ReST 2020-06-02 19:45:05 +02:00
gfs2-uevents.rst docs: filesystems: convert gfs2-uevents.txt to ReST 2020-03-02 14:03:35 -07:00
gfs2.rst Documentation: Update filesystems/gfs2.rst 2020-12-01 00:25:20 +01:00
hfs.rst Replace HTTP links with HTTPS ones: Documentation/filesystems 2020-06-26 11:14:12 -06:00
hfsplus.rst docs: filesystems: convert hfsplus.txt to ReST 2020-03-02 14:03:47 -07:00
hpfs.rst Replace HTTP links with HTTPS ones: Documentation/filesystems 2020-06-26 11:14:12 -06:00
idmappings.rst Documentation: update idmappings.rst 2023-03-14 14:16:57 +01:00
index.rst smb3: move Documentation/filesystems/cifs to Documentation/filesystems/smb 2023-05-24 16:29:21 -05:00
inotify.rst docs: filesystems: convert inotify.txt to ReST 2020-03-02 14:03:55 -07:00
isofs.rst docs: filesystems: convert isofs.txt to ReST 2020-03-02 14:04:06 -07:00
journalling.rst jbd2: drop jbd2_fc_init documentation 2020-11-06 23:01:03 -05:00
locking.rst mm: allow ->huge_fault() to be called without the mmap_lock held 2023-08-24 16:20:29 -07:00
locks.rst docs: fs: locks.rst: update comment about mandatory file locking 2021-10-19 06:48:21 -04:00
mount_api.rst fs_context: drop the unused lsm_flags member 2023-03-16 14:38:28 +01:00
netfs_library.rst netfs: do not unlock and put the folio twice 2022-07-14 10:10:12 +02:00
nilfs2.rst docs: filesystems: convert nilfs2.txt to ReST 2020-03-02 14:04:06 -07:00
ntfs3.rst fs/ntfs3: Remove noacsrules 2023-03-27 16:59:17 +04:00
ntfs.rst docs: filesystems: convert ntfs.txt to ReST 2020-03-02 14:04:06 -07:00
ocfs2-online-filecheck.rst docs: filesystems: convert ocfs2-online-filecheck.txt to ReST 2020-03-02 14:04:06 -07:00
ocfs2.rst docs: update ocfs2-devel mailing list address 2023-07-08 09:29:29 -07:00
omfs.rst Replace HTTP links with HTTPS ones: OMFS 2020-07-13 11:24:43 -06:00
orangefs.rst docs: orangefs: fix pvfs2tab literal block 2020-04-28 12:35:47 -06:00
overlayfs.rst ovl: store enum redirect_mode in config instead of a string 2023-06-19 14:02:01 +03:00
path-lookup.rst Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
path-lookup.txt Replace HTTP links with HTTPS ones: documentation 2020-06-08 09:30:19 -06:00
porting.rst mm: allow ->huge_fault() to be called without the mmap_lock held 2023-08-24 16:20:29 -07:00
proc.rst proc/ksm: add ksm stats to /proc/pid/smaps 2023-09-02 15:17:33 -07:00
qnx6.rst Documentation: filesystems: correct possessive "its" 2022-09-27 13:21:44 -06:00
quota.rst quota: Fixup http links in quota doc 2020-07-09 08:14:01 +02:00
ramfs-rootfs-initramfs.rst Documentation/filesystems: ramfs-rootfs-initramfs: use :Author: 2023-05-16 12:55:35 -06:00
relay.rst docs: filesystems: convert relay.txt to ReST 2020-03-02 14:04:41 -07:00
romfs.rst docs: filesystems: convert romfs.txt to ReST 2020-03-02 14:04:41 -07:00
seq_file.rst seq_file: document how per-entry resources are managed. 2021-02-26 09:41:05 -08:00
sharedsubtree.rst Documentation/filesystems: sharedsubtree: add section headings 2023-05-16 12:50:05 -06:00
splice.rst docs: Bring some order to filesystem documentation 2019-03-06 09:46:10 -07:00
squashfs.rst docs: filesystems: convert squashfs.txt to ReST 2020-03-02 14:04:41 -07:00
sysfs.rst driver core: bus: mark the struct bus_type for sysfs callbacks as constant 2023-03-23 13:20:40 +01:00
sysv-fs.rst docs: filesystems: convert sysv-fs.txt to ReST 2020-03-02 14:04:41 -07:00
tmpfs.rst tmpfs: fix Documentation of noswap and huge mount options 2023-07-27 13:07:03 -07:00
ubifs-authentication.rst docs: ubifs-authentication: Add a top-level heading 2020-09-09 11:53:33 -06:00
ubifs.rst Documentation: ubifs: Fix compression idiom 2022-10-10 13:01:10 -06:00
udf.rst udf: Replace HTTP links with HTTPS ones 2020-07-14 14:37:39 +02:00
vfat.rst docs: filesystems: Fix a mundane typo 2021-03-25 11:51:23 -06:00
vfs.rst sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
virtiofs.rst virtiofs: Add mount option and atime behavior to the doc 2020-04-20 17:01:34 +02:00
xfs-delayed-logging-design.rst Documentation: filesystems: correct possessive "its" 2022-09-27 13:21:44 -06:00
xfs-online-fsck-design.rst xfs: document future directions of online fsck 2023-04-11 18:59:52 -07:00
xfs-self-describing-metadata.rst xfs: document the filesystem metadata checking strategy 2023-04-11 18:59:47 -07:00
zonefs.rst documentation: zonefs: Document sysfs attributes 2022-04-26 14:53:06 +09:00