From: "John Hawkes" <hawkes@sgi.com>
To: "Andrew Morton" <akpm@zip.com.au>, <dipankar@in.ibm.com>
Cc: <davem@redhat.com>, <marcelo@connectiva.com.br>,
<riel@connectiva.com.br>, "Andrea Arcangeli" <andrea@suse.de>,
<torvalds@transmeta.com>, <linux-kernel@vger.kernel.org>,
<hawkes@engr.sgi.com>
Subject: Re: Locking comment on shrink_caches()
Date: Wed, 26 Sep 2001 09:52:12 -0700 [thread overview]
Message-ID: <00ad01c146ab$9d4b6340$6501a8c0@pchawkes> (raw)
In-Reply-To: <20010926103424.A8893@in.ibm.com> <3BB16834.4393EEA3@zip.com.au>
From: "Andrew Morton" <akpm@zip.com.au>
> > John Hawkes from SGI had published some AIM7 numbers that showed
> > pagecache_lock to be a bottleneck above 4 processors. At 32
processors,
> > half the CPU cycles were spent on waiting for pagecache_lock. The
> > thread is at -
> >
> > http://marc.theaimsgroup.com/?l=lse-tech&m=98459051027582&w=2
> >
>
> That's NUMA hardware. The per-hashqueue locking change made
> a big improvement on that hardware. But when it was used on
> Intel hardware it made no measurable difference at all.
More specifically, that was on SGI Origin2000 32p mips64 ccNUMA
hardware. The pagecache_lock bottleneck is substantially less on SGI
Itanium ccNUMA hardware running those AIM7 workloads. I'm seeing
moderately significant contention on the Big Kernel Lock, mostly from
sys_lseek() and ext2_get_block().
John Hawkes
hawkes@sgi.com
next prev parent reply other threads:[~2001-09-26 16:51 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-26 5:04 Dipankar Sarma
2001-09-26 5:31 ` Andrew Morton
2001-09-26 7:08 ` Dipankar Sarma
2001-09-26 16:52 ` John Hawkes [this message]
2001-09-26 6:57 ` David S. Miller
[not found] <fa.cbgmt3v.192gc8r@ifi.uio.no>
[not found] ` <fa.cd0mtbv.1aigc0v@ifi.uio.no>
[not found] ` <i1m66a5o1zc.fsf@verden.pvv.ntnu.no>
2001-09-27 1:34 ` Vojtech Pavlik
-- strict thread matches above, loose matches on Subject: below --
2001-09-25 17:49 Marcelo Tosatti
2001-09-25 19:57 ` David S. Miller
2001-09-25 18:40 ` Marcelo Tosatti
2001-09-25 20:40 ` Josh MacDonald
2001-09-25 19:25 ` Marcelo Tosatti
2001-09-25 20:15 ` David S. Miller
2001-09-25 19:02 ` Marcelo Tosatti
2001-09-25 20:24 ` Rik van Riel
2001-09-25 22:26 ` David S. Miller
2001-09-26 17:42 ` Ingo Molnar
2001-09-25 20:28 ` David S. Miller
2001-09-25 21:05 ` Andrew Morton
2001-09-25 21:48 ` David S. Miller
2001-09-25 20:29 ` David S. Miller
2001-09-25 21:00 ` Benjamin LaHaise
2001-09-25 22:03 ` Andrea Arcangeli
2001-09-25 21:55 ` David S. Miller
2001-09-25 22:16 ` Benjamin LaHaise
2001-09-25 22:28 ` David S. Miller
2001-09-26 16:40 ` Alan Cox
2001-09-26 17:25 ` Linus Torvalds
2001-09-26 17:40 ` Alan Cox
2001-09-26 17:44 ` Linus Torvalds
2001-09-26 18:01 ` Benjamin LaHaise
2001-09-26 18:01 ` Dave Jones
2001-09-26 20:20 ` Vojtech Pavlik
2001-09-26 20:24 ` Vojtech Pavlik
2001-09-26 17:45 ` Dave Jones
2001-09-26 17:50 ` Alan Cox
2001-09-26 17:59 ` Dave Jones
2001-09-26 18:07 ` Alan Cox
2001-09-26 18:09 ` Padraig Brady
2001-09-26 18:22 ` Dave Jones
2001-09-26 18:24 ` Linus Torvalds
2001-09-26 18:40 ` Dave Jones
2001-09-26 19:12 ` Linus Torvalds
2001-09-26 19:04 ` George Greer
2001-09-26 18:59 ` George Greer
2001-09-26 17:43 ` Richard Gooch
2001-09-26 18:24 ` Benjamin LaHaise
2001-09-26 18:48 ` Richard Gooch
2001-09-26 18:58 ` Davide Libenzi
2001-09-26 23:26 ` David S. Miller
2001-09-27 12:10 ` Alan Cox
2001-09-27 15:38 ` Linus Torvalds
2001-09-27 17:44 ` Ingo Molnar
2001-09-27 19:41 ` David S. Miller
2001-09-27 22:59 ` Alan Cox
2001-09-25 22:01 ` Andrea Arcangeli
2001-09-25 22:03 ` David S. Miller
2001-09-25 22:59 ` Andrea Arcangeli
2001-09-25 21:57 ` Andrea Arcangeli
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