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Date:   Tue, 11 May 2021 14:46:32 +0200
From:   Jan Kara <jack@suse.cz>
To:     Amir Goldstein <amir73il@gmail.com>
Cc:     kernel test robot <oliver.sang@intel.com>, Jan Kara <jack@suse.cz>,
        LKML <linux-kernel@vger.kernel.org>, lkp@lists.01.org,
        kbuild test robot <lkp@intel.com>, ying.huang@intel.com,
        feng.tang@intel.com, zhengjun.xing@intel.com,
        Matthew Bobrowski <mbobrowski@mbobrowski.org>
Subject: Re: [fanotify] 7cea2a3c50: stress-ng.fanotify.ops_per_sec -23.4%
 regression
Message-ID: <20210511124632.GL24154@quack2.suse.cz>
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 <CAOQ4uxhoR8h0Mw=LJGSxMYWC1krjbwgzxbYNDjMmeo3sBAey1w@mail.gmail.com>
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On Tue 11-05-21 14:13:38, Amir Goldstein wrote:
> On Tue, May 11, 2021 at 9:51 AM kernel test robot <oliver.sang@intel.com> wrote:
> >
> >
> >
> > Greeting,
> >
> > FYI, we noticed a -23.4% regression of stress-ng.fanotify.ops_per_sec due to commit:
> >
> >
> > commit: 7cea2a3c505e87a9d6afc78be4a7f7be636a73a7 ("fanotify: support limited functionality for unprivileged users")
> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> >
> 
> I am not sure how this is possible.
> This commit only changes permissions to perform the operation.
> Is the test not being run as root?

Yeah, I've stared at it for some time and didn't come up with a sensible
explanation either. I guess we need to try to reproduce and see...

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR