mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Michael Clark <michael@metaparadigm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org
Subject: Re: user-space concurrent pipe buffer scheduler interactions
Date: Thu, 4 Apr 2024 10:02:10 +1300	[thread overview]
Message-ID: <422feb1a-4b4e-45b6-838a-78e394dec9cc@metaparadigm.com> (raw)
In-Reply-To: <1a116a43-fd2e-4f03-8a17-75816fc62717@metaparadigm.com>

On 4/4/24 09:39, Michael Clark wrote:
> So maybe it is possible to look at how many LOCK instructions were 
> retired in the last scheduler quantum ideally with retired-success, 
> retired-failed for interlocked-compare-and-swap. Maybe it is just a 
> performance counter and doesn't require perf tracing switched on?

just occurred to me that you could stash the address and width of the 
last failed interlocked-compare-and-swap to deduce wait-on-address or 
even ask the processor in some circumstances to generate a precise 
interrupt so that you could reschedule it. an idle thought. like if it 
is going to fail we might as well jump straight to the scheduler.

      parent reply	other threads:[~2024-04-03 21:09 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-02 20:53 Michael Clark
2024-04-03 16:56 ` Linus Torvalds
2024-04-03 20:39   ` Michael Clark
2024-04-03 20:57     ` Linus Torvalds
2024-04-04  2:59       ` Michael Clark
2024-04-03 21:02     ` Michael Clark [this message]

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=422feb1a-4b4e-45b6-838a-78e394dec9cc@metaparadigm.com \
    --to=michael@metaparadigm.com \
    --cc=axboe@kernel.dk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=torvalds@linux-foundation.org \
    /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

all inboxes | Powered by JetHome®