On Wed, Sep 15, 2021 at 09:20:08PM +0300, Amir Goldstein wrote: > 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@xxxxxxxxx > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > Signed-off-by: Jan Kara <jack@xxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Link: https://lore.kernel.org/linux-fsdevel/20210202162010.305971-1-amir73il@xxxxxxxxx/ > Link: https://lore.kernel.org/linux-fsdevel/20210915163334.GD6166@xxxxxxxxxxxxxx/ > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > fs/notify/fanotify/fanotify.c | 6 ++++++ > 1 file changed, 6 insertions(+) Now queued up, thanks. greg k-h
