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From: "Dr. David Alan Gilbert" <linux@treblig.org>
To: Ulrich Drepper <drepper@redhat.com>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: getting processor numbers
Date: Tue, 3 Apr 2007 18:56:05 +0100	[thread overview]
Message-ID: <20070403175605.GB1166@gallifrey> (raw)
In-Reply-To: <461286D6.2040407@redhat.com>

* Ulrich Drepper (drepper@redhat.com) wrote:

> glibc for a long time provides functionality to retrieve the number
> through sysconf() and this is what fortunately most programs use.  The
> problem is that we are currently using /proc/cpuinfo since this is all
> there was available at that time.  Creating /proc/cpuinfo takes the
> kernel quite a long time, unfortunately (I think Jakub said it is mainly
> the interrupt information).

It's not only expensive to create, it's expensive and annoying to parse;
I don't think it is vaguely consistent accross different architectures
not to mention kernel versions.

Dave
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    | Running GNU/Linux on Alpha,68K| Happy  \ 
\ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/

  parent reply	other threads:[~2007-04-03 18:36 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-03 16:54 Ulrich Drepper
2007-04-03 17:30 ` linux-os (Dick Johnson)
2007-04-03 17:37   ` Ulrich Drepper
2007-04-03 17:56 ` Dr. David Alan Gilbert [this message]
2007-04-03 18:11 ` Andi Kleen
2007-04-03 17:17   ` Ulrich Drepper
2007-04-03 17:22     ` Alan Cox
2007-04-03 17:30       ` Andi Kleen
2007-04-03 20:24         ` Jeremy Fitzhardinge
2007-04-03 17:27     ` Andi Kleen
2007-04-03 17:30       ` Ulrich Drepper
2007-04-03 17:35         ` Andi Kleen
2007-04-03 17:45           ` Ulrich Drepper
2007-04-03 17:58             ` Andi Kleen
2007-04-03 18:05               ` Ulrich Drepper
2007-04-03 18:11                 ` Andi Kleen
2007-04-03 18:21                   ` Ulrich Drepper
2007-04-03 17:44         ` Siddha, Suresh B
2007-04-03 17:59           ` Ulrich Drepper
2007-04-03 19:40             ` Jakub Jelinek
2007-04-03 20:13             ` Ingo Oeser
2007-04-03 23:38               ` J.A. Magallón
2007-04-03 19:55           ` Ulrich Drepper
2007-04-03 20:13             ` Siddha, Suresh B
2007-04-03 20:19               ` Ulrich Drepper
2007-04-03 20:32                 ` Eric Dumazet
2007-04-03 20:20             ` Nathan Lynch
2007-04-03 19:15 ` Davide Libenzi
2007-04-03 19:32   ` Ulrich Drepper
2007-04-04  0:31     ` H. Peter Anvin
2007-04-04  0:35       ` Jeremy Fitzhardinge
2007-04-04  0:38         ` H. Peter Anvin
2007-04-04  5:09           ` Eric Dumazet
2007-04-04  5:16             ` H. Peter Anvin
2007-04-04  5:22               ` Jeremy Fitzhardinge
2007-04-04  5:40                 ` H. Peter Anvin
2007-04-04  5:46                   ` Eric Dumazet
2007-04-04  5:29               ` Eric Dumazet
2007-04-03 20:16 ` Andrew Morton
     [not found]   ` <4612BB89.8040102@redhat.com>
     [not found]     ` <20070403141348.9bcdb13e.akpm@linux-foundation.org>
2007-04-03 22:13       ` Ulrich Drepper
2007-04-03 22:48         ` Andrew Morton
2007-04-03 23:00           ` Ulrich Drepper
2007-04-03 23:23             ` Andrew Morton
2007-04-03 23:54               ` Ulrich Drepper
2007-04-04  2:55               ` Paul Jackson
2007-04-04  8:39               ` Oleg Nesterov
2007-04-04  9:39                 ` Ingo Molnar
2007-04-04  8:57                   ` Oleg Nesterov
2007-04-04 10:01                     ` Ingo Molnar
2007-04-04  2:58             ` Paul Jackson
2007-04-04  3:04             ` Paul Jackson
2007-04-04  2:52           ` Paul Jackson
2007-04-04  2:04   ` Paul Jackson
2007-04-04  6:47     ` Jakub Jelinek
2007-04-04  7:02       ` Paul Jackson
2007-04-04 14:51       ` Cliff Wickman

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