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From: Ingo Molnar <mingo@elte.hu>
To: P@draigBrady.com
Cc: netdev@oss.sgi.com, Andrea Arcangeli <andrea@suse.de>
Subject: Re: gettimeofday scalability
Date: Tue, 5 Oct 2004 21:18:58 +0200	[thread overview]
Message-ID: <20041005191858.GA14082@elte.hu> (raw)
In-Reply-To: <4162CD76.4070204@draigBrady.com>


* P@draigBrady.com <P@draigBrady.com> wrote:

> In particular I was wondering about reducing the overhead of
> calling do_gettimeofday.

> 2.6.8.1 uses seqlock, which contains the comment that it's not as
> cache friendly as brlock.

that comment is way too modest! Seqlocks are very cache-friendly in the
read path. There is no reason to use brlocks anymore for fixed-frequency
writers like the timer seqlock. (writers can starve seqlock readers but
in the timer case the writers occur only once every 1 msec.)

so please benchmark 2.6, it should scale linearly in this area.

	Ingo

      parent reply	other threads:[~2004-10-05 19:18 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-05 16:36 gettimeofday scalability P
2004-10-05 18:35 ` David S. Miller
2004-10-05 18:48 ` Stephen Hemminger
2004-10-05 18:55 ` Andrea Arcangeli
2004-10-05 19:16   ` P
2004-10-05 19:35     ` Andrea Arcangeli
2004-10-05 19:18 ` Ingo Molnar [this message]

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