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From: Ted Ts'o <tytso@mit.edu>
To: Andi Kleen <andi@firstfloor.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Vivek Haldar <haldar@google.com>,
	Andreas Dilger <adilger@dilger.ca>,
	linux-ext4@vger.kernel.org
Subject: Re: [RFC, PATCH] Avoid hot statistics cache line in ext4 extent cache
Date: Fri, 13 Apr 2012 14:48:23 -0400	[thread overview]
Message-ID: <20120413184823.GA5898@thunk.org> (raw)
In-Reply-To: <20120413184158.GZ17822@one.firstfloor.org>

On Fri, Apr 13, 2012 at 08:41:58PM +0200, Andi Kleen wrote:
> > The reason why I ask this is we're seeing anything like this with Eric
> > Whitney's 48 CPU scalability testing; we're not CPU bottlenecked, and
> > I don't even see evidence of a larger than usual CPU utilization
> > compared to other file systems.
> 
> I bet Eric didn't test with this statistic counter.

Huh?  You can't turn it off, and he's been doing regular scalability
tests at least once per kernel release.

Can you say a bit more about exactly how you are doing this test and
what are the "other issues" where this is becoming a bottleneck?  If
possible I'd like to ask Eric if he can add it to his regular
scalability tests.

Thanks,

						 - Ted

  reply	other threads:[~2012-04-13 18:48 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-23 22:17 [RFC, PATCH] Avoid hot statistics cache line in ext4 extent cache Andi Kleen
2012-03-24  1:10 ` Andreas Dilger
2012-03-24  3:13   ` Andi Kleen
2012-03-26 22:26     ` Vivek Haldar
2012-03-26 23:00       ` Andi Kleen
2012-03-26 23:57         ` Ted Ts'o
2012-04-11 16:59           ` Andi Kleen
2012-04-13 17:42             ` Linus Torvalds
2012-04-13 17:53               ` Tim Chen
2012-04-13 18:08                 ` Linus Torvalds
2012-04-13 18:31                   ` Tim Chen
2012-04-13 18:33                     ` Linus Torvalds
2012-04-13 18:37                     ` Ted Ts'o
2012-04-13 18:41                       ` Andi Kleen
2012-04-13 18:48                         ` Ted Ts'o [this message]
2012-04-13 19:01                           ` Eric Whitney
2012-04-13 19:26                       ` Tim Chen
2012-04-13 19:33                         ` Ted Ts'o
2012-04-13 17:57               ` Andi Kleen
2012-04-13 18:06               ` Ted Ts'o
2012-04-13 18:22                 ` Andi Kleen

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