kernel-fxtec-pro1x/include
Dave Chinner 6c60d2b574 fs/fs-writeback.c: add a new writeback list for sync
wait_sb_inodes() currently does a walk of all inodes in the filesystem
to find dirty one to wait on during sync.  This is highly inefficient
and wastes a lot of CPU when there are lots of clean cached inodes that
we don't need to wait on.

To avoid this "all inode" walk, we need to track inodes that are
currently under writeback that we need to wait for.  We do this by
adding inodes to a writeback list on the sb when the mapping is first
tagged as having pages under writeback.  wait_sb_inodes() can then walk
this list of "inodes under IO" and wait specifically just for the inodes
that the current sync(2) needs to wait for.

Define a couple helpers to add/remove an inode from the writeback list
and call them when the overall mapping is tagged for or cleared from
writeback.  Update wait_sb_inodes() to walk only the inodes under
writeback due to the sync.

With this change, filesystem sync times are significantly reduced for
fs' with largely populated inode caches and otherwise no other work to
do.  For example, on a 16xcpu 2GHz x86-64 server, 10TB XFS filesystem
with a ~10m entry inode cache, sync times are reduced from ~7.3s to less
than 0.1s when the filesystem is fully clean.

Link: http://lkml.kernel.org/r/1466594593-6757-2-git-send-email-bfoster@redhat.com
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Holger Hoffstätte <holger.hoffstaette@applied-asynchrony.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
..
acpi Revert "ACPI 2.0 / AML: Improve module level execution by moving the If/Else/While execution to per-table basis" 2016-07-11 16:21:08 +02:00
asm-generic Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 14:43:00 -07:00
clocksource
crypto
drm Merge branch 'drm-vmwgfx-fixes' of git://people.freedesktop.org/~syeh/repos_linux into drm-fixes 2016-07-15 13:51:55 +10:00
dt-bindings
keys
kvm
linux fs/fs-writeback.c: add a new writeback list for sync 2016-07-26 16:19:19 -07:00
math-emu
media
memory
misc
net net: switchdev: change ageing_time type to clock_t 2016-07-19 16:49:20 -07:00
pcmcia
ras
rdma
rxrpc
scsi
soc
sound
target
trace
uapi Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 13:20:41 -07:00
video
xen
Kbuild