Re: [fanotify] a8b98c808e: stress-ng.fanotify.ops_per_sec 32.2% improvement

[Matthew Bobrowski]

On Thu, Jun 03, 2021 at 10:43:24AM +0200, Jan Kara wrote:
> On Thu 03-06-21 09:57:15, Amir Goldstein wrote:
> > On Thu, Jun 3, 2021 at 4:36 AM kernel test robot <oliver.sang@xxxxxxxxx> wro
> > > Greeting,
> > >
> > > FYI, we noticed a 32.2% improvement of stress-ng.fanotify.ops_per_sec due to commit:
> > >
> > >
> > > commit: a8b98c808eab3ec8f1b5a64be967b0f4af4cae43 ("fanotify: fix permission model of unprivileged group")
> > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> > >
> > >
> > 
> > I guess now we know what caused the reported regression:
> > https://lore.kernel.org/lkml/20210511124632.GL24154@xxxxxxxxxxxxxx/
> > 
> > I didn't know that capable() is so significant.
> 
> Yeah, I wouldn't guess either. Interesting.

Indeed, interesting! :)

While on the topic of stress-ng, it reminds me to set this up on my server
so we can perform such regressions before merging fanotify changes into
master.

/M