From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Klara Modin <klarasmodin@gmail.com>, Mel Gorman <mgorman@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Suren Baghdasaryan <surenb@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH] sched/task_struct: Move alloc_tag to the end of the struct.
Date: Fri, 21 Jun 2024 21:22:52 +0200 [thread overview]
Message-ID: <20240621192252.-whn_Ae8@linutronix.de> (raw)
In-Reply-To: <elqyw2tofbojh6rfkfyrjaz6dpwpq4vfd3ni5r3cgkwdumginc@ctizxnu4jkff>
On 2024-06-21 15:13:19 [-0400], Kent Overstreet wrote:
> > > > random code… Puh. So if the end is too cold, what about around the mm
> > > > pointer?
> > >
> > > Not there, that's not actually that hot. It needs to be by
> > > task_struct->flags; that's used in the same paths.
> >
> > But there is no space without the additional 52 bytes. Was this by any
> > chance on purpose?
>
> No, that wasn't, and it doesn't have to be the exact same cacheline, but
> we do want it near current->flags; we store PF_MEMALLOC flags there that
> are converted to gfp flags and used exactly where we're using
> current->alloc_tag.
Hmm. `stack' and `usage' are the only two member that you would have to
move (away) in order the stash the conditional variable there. The
`ptrace' one uses the same flags as `flags' so it wouldn't make sense to
move that one.
Sebastian
next prev parent reply other threads:[~2024-06-21 19:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-21 10:27 [PATCH] sched/task_struct: Move alloc_tag to the end of the struct Sebastian Andrzej Siewior
2024-06-21 14:20 ` Kent Overstreet
2024-06-21 18:29 ` Sebastian Andrzej Siewior
2024-06-21 18:49 ` Kent Overstreet
2024-06-21 19:07 ` Sebastian Andrzej Siewior
2024-06-21 19:13 ` Kent Overstreet
2024-06-21 19:22 ` Sebastian Andrzej Siewior [this message]
2024-06-28 9:49 ` Sebastian Andrzej Siewior
2024-06-28 19:20 ` Andrew Morton
2024-06-28 19:35 ` Kent Overstreet
2024-06-28 19:55 ` Sebastian Andrzej Siewior
2024-06-28 20:20 ` Kent Overstreet
2024-06-30 21:11 ` Sebastian Andrzej Siewior
2024-06-30 21:23 ` Kent Overstreet
2024-07-01 8:05 ` Sebastian Andrzej Siewior
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=20240621192252.-whn_Ae8@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=akpm@linux-foundation.org \
--cc=bristot@redhat.com \
--cc=bsegall@google.com \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=kent.overstreet@linux.dev \
--cc=klarasmodin@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=surenb@google.com \
--cc=tglx@linutronix.de \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.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;
as well as URLs for NNTP newsgroup(s).