From: "Martin J. Bligh" <mbligh@aracnet.com>
To: bert hubert <ahu@ds9a.nl>
Cc: Peter Chubb <peter@chubb.wattle.id.au>,
jw schultz <jw@pegasys.ws>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: ps performance sucks (was Re: dcache_rcu [performance results])
Date: Tue, 05 Nov 2002 16:57:47 -0800 [thread overview]
Message-ID: <27920000.1036544267@flay> (raw)
In-Reply-To: <20021105231649.GA14511@outpost.ds9a.nl>
>> The locking of walking the tasklist seems non-trivial, but we may well
>> end up with something like that. By the time you finish, it looks more
>> like a /dev device thing than /proc (which I'm fine with), and looks
>
> Can people just oprofile this instead of guessing? Opening a file is not
> very expensive anymore, so if ps is noticeably slow, it must be something
> else.
>
> 'To measure is to know'
Errm... we have profiled it. Look at the subject line ... this started
off as a dcache_rcu discussion. The dcache lookup ain't cheap, for
starters, but that's not really the problem ... it's O(number of tasks),
which sucks.
M.
next prev parent reply other threads:[~2002-11-05 23:58 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <993103655@toto.iv>
2002-11-05 22:49 ` ps performance sucks (was Re: dcache_rcu [performance results]) Peter Chubb
2002-11-06 0:06 ` Martin J. Bligh
2002-11-05 23:16 ` bert hubert
2002-11-06 0:57 ` Martin J. Bligh [this message]
2002-11-06 0:10 ` bert hubert
2002-11-06 1:23 ` Martin J. Bligh
2002-11-06 0:34 ` Alexander Viro
2002-11-07 12:06 ` Rusty Russell
2002-11-08 3:57 ` William Lee Irwin III
2002-11-08 4:17 ` Robert Love
2002-11-08 4:27 ` Daniel Jacobowitz
2002-11-08 4:29 ` William Lee Irwin III
2002-10-30 10:49 [PATCH 2.5.44] dcache_rcu Maneesh Soni
2002-10-31 10:53 ` dcache_rcu [performance results] Dipankar Sarma
2002-11-02 1:36 ` Andrew Morton
2002-11-02 9:13 ` Dipankar Sarma
2002-11-04 17:29 ` Martin J. Bligh
2002-11-05 0:00 ` jw schultz
2002-11-05 1:14 ` ps performance sucks (was Re: dcache_rcu [performance results]) Martin J. Bligh
2002-11-05 3:57 ` Werner Almesberger
2002-11-05 4:42 ` Erik Andersen
2002-11-05 5:44 ` Martin J. Bligh
2002-11-05 5:59 ` Alexander Viro
2002-11-05 6:05 ` Martin J. Bligh
2002-11-05 6:15 ` Robert Love
2002-11-05 6:13 ` Erik Andersen
2002-11-05 6:14 ` Werner Almesberger
2002-11-05 4:26 ` jw schultz
2002-11-05 5:51 ` Martin J. Bligh
2002-11-05 19:57 ` Kai Henningsen
2002-11-05 21:33 ` Erik Andersen
2002-11-05 22:09 ` Karim Yaghmour
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