Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-14 07:02:23 +00:00
Code Issues Packages Projects Releases Wiki Activity
6a15a37097
linux/fs
History
Vlastimil Babka 6a15a37097 mm, proc: reduce cost of /proc/pid/smaps for shmem mappings 
The previous patch has improved swap accounting for shmem mapping, which
however made /proc/pid/smaps more expensive for shmem mappings, as we
consult the radix tree for each pte_none entry, so the overal complexity
is O(n*log(n)).

We can reduce this significantly for mappings that cannot contain COWed
pages, because then we can either use the statistics tha shmem object
itself tracks (if the mapping contains the whole object, or the swap
usage of the whole object is zero), or use the radix tree iterator,
which is much more effective than repeated find_get_entry() calls.

This patch therefore introduces a function shmem_swap_usage(vma) and
makes /proc/pid/smaps use it when possible.  Only for writable private
mappings of shmem objects (i.e.  tmpfs files) with the shmem object
itself (partially) swapped outwe have to resort to the find_get_entry()
approach.

Hopefully such mappings are relatively uncommon.

To demonstrate the diference, I have measured this on a process that
creates a 2GB mapping and dirties single pages with a stride of 2MB, and
time how long does it take to cat /proc/pid/smaps of this process 100
times.

Private writable mapping of a /dev/shm/file (the most complex case):

real    0m3.831s
user    0m0.180s
sys     0m3.212s

Shared mapping of an almost full mapping of a partially swapped /dev/shm/file
(which needs to employ the radix tree iterator).

real    0m1.351s
user    0m0.096s
sys     0m0.768s

Same, but with /dev/shm/file not swapped (so no radix tree walk needed)

real    0m0.935s
user    0m0.128s
sys     0m0.344s

Private anonymous mapping:

real    0m0.949s
user    0m0.116s
sys     0m0.348s

The cost is now much closer to the private anonymous mapping case, unless
the shmem mapping is private and writable.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
..
9p kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
adfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
affs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
afs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
autofs4 switch ->get_link() to delayed_call, kill ->put_link() 2015-12-30 13:01:03 -05:00
befs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
bfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
btrfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
cachefiles convert a bunch of open-coded instances of memdup_user_nul() 2016-01-04 10:26:58 -05:00
ceph kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
cifs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
coda kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
configfs Configfs changes for the 4.5 merge window: 2016-01-12 18:15:34 -08:00
cramfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
debugfs debugfs: fix refcount imbalance in start_creating 2015-11-11 02:04:44 -05:00
devpts
dlm convert a bunch of open-coded instances of memdup_user_nul() 2016-01-04 10:26:58 -05:00
ecryptfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
efivarfs
efs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
exofs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
exportfs
ext2 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
ext4 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
f2fs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
fat kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
freevxfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
fscache FS-Cache: Handle a write to the page immediately beyond the EOF marker 2015-11-11 02:11:02 -05:00
fuse kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
gfs2 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
hfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
hfsplus kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
hostfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
hpfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
hugetlbfs mm/mempolicy.c: convert the shared_policy lock to a rwlock 2016-01-14 16:00:49 -08:00
isofs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
jbd2 fs: use block_device name vsprintf helper 2016-01-06 13:03:18 -05:00
jffs2 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
jfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
kernfs Revert "kernfs: do not account ino_ida allocations to memcg" 2016-01-14 16:00:49 -08:00
lockd Mainly smaller bugfixes and cleanup. We're still finding some bugs from 2015-11-11 20:11:28 -08:00
logfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
minix kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
ncpfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
nfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
nfs_common
nfsd Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
nilfs2 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
nls
notify fsnotify: destroy marks with call_srcu instead of dedicated thread 2016-01-14 16:00:49 -08:00
ntfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
ocfs2 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
omfs
openpromfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
overlayfs switch ->get_link() to delayed_call, kill ->put_link() 2015-12-30 13:01:03 -05:00
proc mm, proc: reduce cost of /proc/pid/smaps for shmem mappings 2016-01-14 16:00:49 -08:00
pstore pstore: fix code comment to match code 2015-11-02 13:41:52 -08:00
qnx4 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
qnx6 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
quota
ramfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
reiserfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
romfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
squashfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
sysfs platform/chrome: Branch for v4.4 2015-11-13 21:53:18 -08:00
sysv kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
tracefs tracefs: Fix refcount imbalance in start_creating() 2015-11-04 22:13:45 -05:00
ubifs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
udf kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
ufs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
xfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
aio.c
anon_inodes.c
attr.c
bad_inode.c fs/bad_inode.c: is_bad_inode can be boolean 2015-12-06 21:17:14 -05:00
binfmt_aout.c
binfmt_elf_fdpic.c libnvdimm for 4.4: 2015-11-10 12:07:22 -08:00
binfmt_elf.c Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-11-11 09:45:24 -08:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
buffer.c fs: use block_device name vsprintf helper 2016-01-06 13:03:18 -05:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
compat.c saner calling conventions for copy_mount_options() 2016-01-04 10:28:32 -05:00
coredump.c coredump: Use 64bit time for unix time of coredump 2015-12-06 21:17:17 -05:00
dax.c dax: disable pmd mappings 2015-11-16 23:54:45 -08:00
dcache.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
dcookies.c
direct-io.c fix the regression from "direct-io: Fix negative return from dio read beyond eof" 2015-12-08 15:02:42 -05:00
drop_caches.c
eventfd.c
eventpoll.c
exec.c don't carry MAY_OPEN in op->acc_mode 2016-01-04 10:28:40 -05:00
fcntl.c fcntl: allow to set O_DIRECT flag on pipe 2016-01-09 02:55:37 -05:00
fhandle.c
file_table.c
file.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
filesystems.c
fs_pin.c
fs_struct.c
fs-writeback.c fs: fix writeback.c kernel-doc warnings 2015-11-11 02:18:27 -05:00
inode.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
internal.h Merge branch 'for-linus' into work.misc 2016-01-08 21:20:11 -05:00
ioctl.c Merge branch 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 16:30:34 -08:00
Kconfig File locking related changes for v4.5 (pile #1) 2016-01-12 15:46:17 -08:00
Kconfig.binfmt
libfs.c switch ->get_link() to delayed_call, kill ->put_link() 2015-12-30 13:01:03 -05:00
locks.c Merge branch 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 16:30:34 -08:00
Makefile
mbcache.c
mount.h
mpage.c mm, fs: introduce mapping_gfp_constraint() 2015-11-06 17:50:42 -08:00
namei.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
namespace.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
no-block.c
nsfs.c
open.c don't carry MAY_OPEN in op->acc_mode 2016-01-04 10:28:40 -05:00
pipe.c fs/pipe.c: return error code rather than 0 in pipe_write() 2015-11-11 02:18:26 -05:00
pnode.c
pnode.h
posix_acl.c xattr handlers: Simplify list operation 2015-12-13 19:46:12 -05:00
proc_namespace.c vfs: show_vfsstat: remove redundant initialization and check of error code 2015-12-06 21:17:16 -05:00
read_write.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
readdir.c
select.c poll: plug an unused argument to do_poll 2016-01-06 08:26:52 -05:00
seq_file.c fs, seqfile: always allow oom killer 2015-11-06 17:50:42 -08:00
signalfd.c
splice.c fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE 2016-01-09 02:55:35 -05:00
stack.c
stat.c fs/stat.c: remove unnecessary new_valid_dev() check 2015-11-09 15:11:24 -08:00
statfs.c
super.c fs: use block_device name vsprintf helper 2016-01-06 13:03:18 -05:00
sync.c fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE writeback 2015-11-06 17:50:42 -08:00
timerfd.c
userfaultfd.c
utimes.c
xattr.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00