From: Linus Torvalds <torvalds@linux-foundation.org>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: kernel test robot <oliver.sang@intel.com>,
oe-lkp@lists.linux.dev, lkp@intel.com,
Linux Memory Management List <linux-mm@kvack.org>,
Christian Brauner <brauner@kernel.org>,
linux-kernel@vger.kernel.org, ying.huang@intel.com,
feng.tang@intel.com, fengwei.yin@intel.com
Subject: Re: [linux-next:master] [lockref] d042dae6ad: unixbench.throughput -33.7% regression
Date: Thu, 27 Jun 2024 09:57:13 -0700 [thread overview]
Message-ID: <CAHk-=wjkn=yL6vy5s7ZFgBfDybD3Gjg9C72zXchy-JF0Tp+a+A@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wg7PXo_QbBo8gv27OpbMgAwLh9H46kJRxAmp0FL0QD7HA@mail.gmail.com>
On Thu, 27 Jun 2024 at 09:32, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> getdent subtest:
> +4.1 lockref_put_return
> +5.7 lockref_get_not_dead
> +68.0 native_queued_spin_lock_slowpath
For this getdents load, the main call chains that terminate in the
queued spinlock case seem to be
.lockref_get_not_dead.__legitimize_path.try_to_unlazy_next.lookup_fast
.lockref_get_not_dead.__legitimize_path.try_to_unlazy.lookup_fast
.lockref_get_not_dead.__legitimize_path.try_to_unlazy.link_path_walk
.dput.terminate_walk.path_openat.do_filp_open
which is interesting because I would have expected the readdir() code
itself to show up.
But the proc_pident_readdir profiles have all gone down, presumably
because there's just much fewer of them. That part shows no spinlock
in the profile at all.
WTH is that benchmark doing? The only readdir that shows up is for
what looks like some /proc filesystem thing.
Linus
next prev parent reply other threads:[~2024-06-27 16:57 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-27 2:41 kernel test robot
2024-06-27 6:25 ` Mateusz Guzik
2024-06-27 7:00 ` Mateusz Guzik
2024-06-27 16:32 ` Linus Torvalds
2024-06-27 16:55 ` Mateusz Guzik
2024-06-27 16:57 ` Linus Torvalds [this message]
2024-06-27 17:20 ` Mateusz Guzik
2024-06-27 17:23 ` Linus Torvalds
2024-07-02 7:19 ` Mateusz Guzik
2024-07-02 12:10 ` Mateusz Guzik
2024-07-02 16:47 ` Linus Torvalds
2024-07-02 17:02 ` Mateusz Guzik
2024-07-02 17:28 ` Linus Torvalds
2024-07-02 17:46 ` Mateusz Guzik
2024-07-02 17:58 ` Mateusz Guzik
2024-07-02 18:41 ` Linus Torvalds
2024-07-02 20:33 ` Mateusz Guzik
2024-07-02 20:42 ` Linus Torvalds
2024-07-02 21:15 ` Mateusz Guzik
2024-07-02 22:14 ` Linus Torvalds
2024-07-03 13:53 ` Mateusz Guzik
2024-07-03 14:08 ` Christian Brauner
2024-07-03 14:11 ` Mateusz Guzik
2024-07-03 16:47 ` Linus Torvalds
2024-07-03 8:34 ` Christian Brauner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAHk-=wjkn=yL6vy5s7ZFgBfDybD3Gjg9C72zXchy-JF0Tp+a+A@mail.gmail.com' \
--to=torvalds@linux-foundation.org \
--cc=brauner@kernel.org \
--cc=feng.tang@intel.com \
--cc=fengwei.yin@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lkp@intel.com \
--cc=mjguzik@gmail.com \
--cc=oe-lkp@lists.linux.dev \
--cc=oliver.sang@intel.com \
--cc=ying.huang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox