kernel_optimize_test/fs/notify
Amir Goldstein ad3ea16746 fanotify: limit number of event merge attempts
commit b8cd0ee8cda68a888a317991c1e918a8cba1a568 upstream.

Event merges are expensive when event queue size is large, so limit the
linear search to 128 merge tests.

[Stable backport notes] The following statement from upstream commit is
irrelevant for backport:
-
-In combination with 128 size hash table, there is a potential to merge
-with up to 16K events in the hashed queue.
-
[Stable backport notes] The problem is as old as fanotify and described
in the linked cover letter "Performance improvement for fanotify merge".
This backported patch fixes the performance issue at the cost of merging
fewer potential events.  Fixing the performance issue is more important
than preserving the "event merge" behavior, which was not predictable in
any way that applications could rely on.

Link: https://lore.kernel.org/r/20210304104826.3993892-6-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/linux-fsdevel/20210202162010.305971-1-amir73il@gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20210915163334.GD6166@quack2.suse.cz/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18 13:40:38 +02:00
..
dnotify fsnotify: generalize handle_inode_event() 2020-12-30 11:54:18 +01:00
fanotify fanotify: limit number of event merge attempts 2021-09-18 13:40:38 +02:00
inotify inotify: convert to handle_inode_event() interface 2020-12-30 11:54:18 +01:00
fdinfo.c fsnotify: Remove proc_fs.h include 2020-05-13 17:16:14 +02:00
fdinfo.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fsnotify.c fsnotify: fix events reported to watching parent and child 2020-12-30 11:54:18 +01:00
fsnotify.h fsnotify: move declaration of fsnotify_mark_connector_cachep to fsnotify.h 2019-10-17 10:31:12 +02:00
group.c fsnotify: add mutex destroy 2020-05-13 17:14:20 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mark.c fsnotify: Add missing annotation for fsnotify_finish_user_wait() and for fsnotify_prepare_user_wait() 2020-04-15 11:44:43 +02:00
notification.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18 2019-05-21 11:28:46 +02:00