From: Con Kolivas <kernel@kolivas.org>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: linux-kernel@vger.kernel.org, "Chen,
Kenneth W" <kenneth.w.chen@intel.com>,
"'Chris Mason'" <mason@suse.com>, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH RFC] smt nice introduces significant lock contention
Date: Fri, 2 Jun 2006 20:19:28 +1000 [thread overview]
Message-ID: <200606022019.29023.kernel@kolivas.org> (raw)
In-Reply-To: <447FF6B8.1000700@yahoo.com.au>
On Friday 02 June 2006 18:28, Nick Piggin wrote:
> Con Kolivas wrote:
> > On Friday 02 June 2006 17:53, Nick Piggin wrote:
> >>This is a small micro-optimisation / cleanup we can do after
> >>smtnice gets converted to use trylocks. Might result in a little
> >>less cacheline footprint in some cases.
> >
> > It's only dependent_sleeper that is being converted in these patches. The
> > wake_sleeping_dependent component still locks all runqueues and needs to
>
> Oh I missed that.
>
> > succeed in order to ensure a task doesn't keep sleeping indefinitely.
> > That
>
> Let's make it use trylocks as well. wake_priority_sleeper should ensure
> things don't sleep forever I think? We should be optimising for the most
> common case, and in many workloads, the runqueue does go idle frequently.
wake_priority_sleeper is only called per tick which can be 10ms at 100HZ. I
don't think that's fast enough. It could even be possible for a lower
priority task to always just miss the wakeup if it's (very) unlucky.
--
-ck
next prev parent reply other threads:[~2006-06-02 10:19 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-01 22:55 [PATCH RFC] smt nice introduces significant lock contention Chris Mason
2006-06-01 23:57 ` Chen, Kenneth W
2006-06-02 1:59 ` Con Kolivas
2006-06-02 2:28 ` Con Kolivas
2006-06-02 3:55 ` Con Kolivas
2006-06-02 4:18 ` Nick Piggin
2006-06-02 6:08 ` Con Kolivas
2006-06-02 7:53 ` Nick Piggin
2006-06-02 8:17 ` Con Kolivas
2006-06-02 8:28 ` Nick Piggin
2006-06-02 8:34 ` Chen, Kenneth W
2006-06-02 8:56 ` Nick Piggin
2006-06-02 9:17 ` Chen, Kenneth W
2006-06-02 9:25 ` Con Kolivas
2006-06-02 9:31 ` Chen, Kenneth W
2006-06-02 9:34 ` Con Kolivas
2006-06-02 9:53 ` Chen, Kenneth W
2006-06-02 10:12 ` Con Kolivas
2006-06-02 20:53 ` Chen, Kenneth W
2006-06-02 22:15 ` Con Kolivas
2006-06-02 22:19 ` Chen, Kenneth W
2006-06-02 22:31 ` Con Kolivas
2006-06-02 22:58 ` Chen, Kenneth W
2006-06-03 0:02 ` Con Kolivas
2006-06-03 0:08 ` Chen, Kenneth W
2006-06-03 0:27 ` Con Kolivas
2006-06-02 9:36 ` Chen, Kenneth W
2006-06-02 10:30 ` Con Kolivas
2006-06-02 13:16 ` Con Kolivas
2006-06-02 21:54 ` Chen, Kenneth W
2006-06-02 22:04 ` Con Kolivas
2006-06-02 22:14 ` Chen, Kenneth W
2006-06-02 10:19 ` Con Kolivas [this message]
2006-06-02 20:59 ` Chen, Kenneth W
2006-06-02 8:38 ` Chen, Kenneth W
2006-06-02 8:24 ` Chen, Kenneth W
2006-06-02 8:31 ` Chen, Kenneth W
2006-06-02 8:50 ` Chen, Kenneth W
2006-06-02 2:35 ` Chen, Kenneth W
2006-06-02 3:04 ` Con Kolivas
2006-06-02 3:23 ` Con Kolivas
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