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From: Robert Love <rml@tech9.net>
To: Andrew Morton <akpm@zip.com.au>
Cc: Linus Torvalds <torvalds@transmeta.com>,
	viro@math.psu.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] 2.5: push BKL out of llseek
Date: 29 Jan 2002 21:20:10 -0500	[thread overview]
Message-ID: <1012357211.817.67.camel@phantasy> (raw)
In-Reply-To: <3C574BD1.E5343312@zip.com.au>
In-Reply-To: <Pine.LNX.4.33.0201291602510.1747-100000@penguin.transmeta.com>, <Pine.LNX.4.33.0201291602510.1747-100000@penguin.transmeta.com> <1012351309.813.56.camel@phantasy>  <3C574BD1.E5343312@zip.com.au>

On Tue, 2002-01-29 at 20:26, Andrew Morton wrote:

> Just a little word of caution here.  Remember the
> apache-flock-synchronisation fiasco, where removal
> of the BKL halved Apache throughput on 8-way x86.
> 
> This was because the BKL removal turned serialisation
> on a quick codepath from a spinlock into a schedule().

I feared this too, but eventually I decided it was worth it and
benchmarks backed that up.  If nothing else this is yet-another-excuse
for locks that can spin-then-sleep.

I posted dbench results, which show a positive gain even on 2-way for
multiple client loads.

	Robert Love


  parent reply	other threads:[~2002-01-30  2:14 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-01-30  0:00 [PATCH] 2.5: push BKL out of llseek Robert Love
2002-01-30  0:09 ` Linus Torvalds
2002-01-30  0:41   ` Robert Love
2002-01-30  0:52     ` Linus Torvalds
2002-01-30  2:24       ` Robert Love
2002-01-30  1:26     ` Andrew Morton
2002-01-30  2:16       ` Linus Torvalds
2002-01-30  2:20       ` Robert Love [this message]
2002-01-30  2:20         ` Andrew Morton
2002-01-30  2:21         ` Dave Jones
2002-01-30  2:37           ` Robert Love
2002-01-30  2:50         ` Nigel Gamble
2002-01-30  3:19           ` Andrew Morton
2002-01-30  9:34             ` Nigel Gamble
2002-01-30 10:36         ` Russell King
2002-01-30  4:54   ` Alexander Viro
2002-01-30  8:00     ` Trond Myklebust
2002-01-30 13:39       ` Robert Love
2002-01-30  4:50 ` Anton Blanchard
2002-01-30  5:03 ` Robert Love
  -- strict thread matches above, loose matches on Subject: below --
2002-01-30 21:14 Martin Wirth
2002-01-31 15:39 Martin Wirth
2002-01-31 21:06 ` Nigel Gamble
2002-02-01 19:29 John Hawkes

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