On Sun, May 05, 2019 at 12:15:49PM +0300, Amir Goldstein wrote:
__fsnotify_parent() has an optimization in place to avoid unneeded
take_dentry_name_snapshot(). When fsnotify_nameremove() was changed
not to call __fsnotify_parent(), we left out the optimization.
Kernel test robot reported a 5% performance regression in concurrent
unlink() workload.
Reported-by: kernel test robot <rong.a.chen(a)intel.com>
Link:
https://lore.kernel.org/lkml/20190505062153.GG29809@shao2-debian/
Link:
https://lore.kernel.org/linux-fsdevel/20190104090357.GD22409@quack2.suse.cz/
Fixes: 5f02a8776384 ("fsnotify: annotate directory entry modification events")
Signed-off-by: Amir Goldstein <amir73il(a)gmail.com>
---
Jan,
The linked 5.1-rc1 performance regression report came with bad timing.
Not sure if Linus is planning an rc8. If not, you will probably not
see this before the 5.1 release and we shall have to queue it for 5.2
and backport to stable 5.1.
I crafted the patch so it applies cleanly both to master and Al's
for-next branch (there are some fsnotify changes in work.dcache).
Charming... What about rename() and matching regressions there?