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From: Andi Kleen <andi@firstfloor.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Harvey Harrison <harvey.harrison@gmail.com>,
	Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	David Miller <davem@davemloft.net>
Subject: Re: [PATCH] bitops: simplify generic bit finding functions
Date: Mon, 28 Apr 2008 21:57:33 +0200	[thread overview]
Message-ID: <874p9liwgi.fsf@basil.nowhere.org> (raw)
In-Reply-To: <alpine.LFD.1.10.0804280953570.3119@woody.linux-foundation.org> (Linus Torvalds's message of "Mon, 28 Apr 2008 09:54:37 -0700 (PDT)")

Linus Torvalds <torvalds@linux-foundation.org> writes:
>
> Is there a real hot path anywhere that actually uses this and depends on 
> it?

A long time ago during profiling I found that in the scheduler back then
for_each_cpu() with find_next_bit() was somewhat hot. But I'm not sure it 
still would be in the new scheduler anyways and the test case a little
dumb anyways (overscheduling user space)

Still I think for_each_cpu() should be reasonably stream lined code.

-Andi

  parent reply	other threads:[~2008-04-28 19:58 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-27 20:19 [PATCH] bitops: simplify generic bit finding functions Harvey Harrison
2008-04-27 20:26 ` Linus Torvalds
2008-04-27 20:29   ` Harvey Harrison
2008-04-27 20:36     ` Al Viro
2008-04-27 20:38       ` Harvey Harrison
2008-04-27 20:38     ` Linus Torvalds
2008-04-27 21:02       ` Al Viro
2008-04-28 14:04   ` Thomas Gleixner
2008-04-28 15:10     ` Alexander van Heukelum
2008-04-28 15:58       ` Thomas Gleixner
2008-04-28 16:25     ` Linus Torvalds
2008-04-28 16:47       ` Thomas Gleixner
2008-04-28 16:54         ` Linus Torvalds
2008-04-28 19:26           ` Thomas Gleixner
2008-04-28 19:37             ` Linus Torvalds
2008-04-28 21:55               ` Ingo Molnar
2008-04-29 10:01               ` [PATCH] bitops: remove "optimizations" Thomas Gleixner
2008-04-29 10:03                 ` David Miller
2008-04-29 12:34                   ` David Miller
2008-04-29 14:20                     ` Ingo Molnar
2008-04-29 22:31                       ` David Miller
2008-04-29 16:51                     ` Thomas Gleixner
2008-04-29 22:58                       ` David Miller
2008-04-29 23:30                         ` David Miller
2008-04-28 19:57           ` Andi Kleen [this message]
2008-04-28 14:58   ` [PATCH] bitops: simplify generic bit finding functions Alexander van Heukelum
2008-04-28 14:32 ` Alexander van Heukelum

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