Hi Amir!
On Wed 23-02-22 17:14:36, Amir Goldstein wrote:
> The two patches are functionally unrelated, but they both incorporate
> information from the ignored mask into the object's interest mask.
>
> The 1st patch is a fix for a minor functional bug.
> LTP test fanotify10 has a workaround for this bug, see comment:
> /* XXX: temporary hack may be removed in the future */
> The test is to remove the hack and see that fanotify10 passes.
>
> The 2nd patch is a performance optimization that you suggested.
> Last time I posted it, you asked for performance numbers [1], so I ran
> some micro benchmarks (see results below [3]).
>
> Note that the other patch from that first posting ("optimize merging of
> marks with no ignored masks") did not demonstrate any visible
> improvements with the benchmarks that I ran so I left it out.
>
> The micro benchmark is a simple program [2] that writes 1 byte at a time
> in a loop. I ran it on tmpfs once without any mark and once with a mark
> with a mask for DELETE_SELF event.
>
> On upstream kernel, runtime with a mark is always ~25% longer.
> With the optimization patch applied, runtime with a mark is most of the
> time (but not always) very close to the runtime without a mark.
>
> [1] https://lore.kernel.org/linux-fsdevel/20201203145220.GH11854@xxxxxxxxxxxxxx/
> [2] https://github.com/amir73il/fsnotify-utils/blob/master/src/test/ioloop.c
> [3] Performance test results:
Thanks! Both patches look good to me, I have added them to my tree (just
included shortened performance results into the changelog of the second
patch).
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
