public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Lee Revell <rlrevell@joe-job.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>
Subject: Re: 2.6.16-rc1: 28ms latency when process with lots of swapped memory exits
Date: Tue, 14 Mar 2006 14:05:45 -0500	[thread overview]
Message-ID: <1142363146.13256.145.camel@mindpipe> (raw)
In-Reply-To: <Pine.LNX.4.61.0603141812400.5882@goblin.wat.veritas.com>

On Tue, 2006-03-14 at 18:40 +0000, Hugh Dickins wrote:
> On Tue, 14 Mar 2006, Lee Revell wrote:
> 
> > I've been testign for weeks with 2.6.16-rc1 + the latency trace patch
> > and the longest latencies measured were 10-15ms due to the well known
> > rt_run_flush issue.  Today I got one twice as long, when a Firefox
> > process with a bunch of acroreads in tabs, from a new code path.
> > 
> > It seems to trigger when a process with a large amount of memory swapped
> > out exits.
> > 
> > Can this be solved with a cond_resched?
> 
> Not that easily, I think.
> 
> Are you testing with CONFIG_PREEMPT=y, as I'd expect?  I thought
> cond_resched() adds nothing to that case (and we keep on intending
> but forgetting to make it compile away to nothing in that case).
> Or am I confused?
> 

Thanks for the explanation - I am the one confused (PREEMPT is on so
cond_resched would be pointless).

Lee


  reply	other threads:[~2006-03-14 19:05 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-14 16:15 2.6.16-rc1: 28ms latency when process with lots of swapped memory exits Lee Revell
2006-03-14 18:40 ` Hugh Dickins
2006-03-14 19:05   ` Lee Revell [this message]
2006-03-14 21:01   ` Ingo Molnar
2006-03-14 22:38     ` Lee Revell
2006-03-15  7:52       ` Hugh Dickins
2006-03-15 11:19         ` Nick Piggin
2006-03-14 21:22 ` Ingo Molnar
2006-03-14 22:12   ` Lee Revell

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=1142363146.13256.145.camel@mindpipe \
    --to=rlrevell@joe-job.com \
    --cc=hugh@veritas.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    /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