From: "H. Peter Anvin" <hpa@zytor.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Jakub Jelinek <jakub@redhat.com>,
Ulrich Drepper <drepper@redhat.com>,
Roland McGrath <roland@redhat.com>,
"Randy.Dunlap" <rdunlap@xenotime.net>,
akpm@osdl.org, linux-kernel@vger.kernel.org,
libc-alpha@sourceware.org
Subject: Re: [PATCH] Use uname not sysctl to get the kernel revision
Date: Wed, 12 Jul 2006 15:02:57 -0700 [thread overview]
Message-ID: <44B57191.5000802@zytor.com> (raw)
In-Reply-To: <1152741665.3217.85.camel@laptopd505.fenrus.org>
Arjan van de Ven wrote:
>> It is a short busy wait before falling asleep. I assume you mean
>> busy wait is a loss even on SMP?
>
> eh yeah I forgot to think for a second. But yes even for SMP busy wait
> is pretty bad power wise nowadays.. at least if you wait more than a few
> hundred cycles. (and if you wait less... then it's almost unlikely that
> it'll be useful as well)
>
It depends greatly; if a lock is likely to get released by the user
after a few memory accesses, spinning is likely to be a win.
-hpa
next prev parent reply other threads:[~2006-07-12 22:03 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-10 22:39 [PATCH] sysctl: Document that sys_sysctl will be removed Eric W. Biederman
2006-07-10 22:50 ` Randy.Dunlap
2006-07-11 4:10 ` Eric W. Biederman
2006-07-11 7:07 ` Arjan van de Ven
2006-07-12 16:25 ` [PATCH] Use uname not sysctl to get the kernel revision Eric W. Biederman
2006-07-12 16:50 ` Ulrich Drepper
2006-07-12 17:42 ` Eric W. Biederman
2006-07-12 23:24 ` Theodore Tso
2006-07-12 23:31 ` Andi Kleen
2006-07-13 0:12 ` Theodore Tso
2006-07-13 2:33 ` Eric W. Biederman
2006-07-13 12:15 ` Andi Kleen
2006-07-12 23:44 ` Steve Munroe
2006-07-14 18:49 ` Benjamin Herrenschmidt
2006-07-14 19:09 ` Andi Kleen
2006-07-13 0:19 ` Eric W. Biederman
2006-07-12 18:44 ` Roland McGrath
2006-07-12 19:33 ` Ulrich Drepper
2006-07-12 19:53 ` Jakub Jelinek
2006-07-12 20:09 ` H. Peter Anvin
2006-07-12 21:23 ` Eric W. Biederman
2006-07-12 21:29 ` Arjan van de Ven
2006-07-12 21:56 ` Eric W. Biederman
2006-07-12 22:01 ` Arjan van de Ven
2006-07-12 22:02 ` H. Peter Anvin [this message]
2006-07-12 22:26 ` Eric W. Biederman
2006-07-12 22:31 ` H. Peter Anvin
2006-07-12 23:07 ` Alan Cox
2006-07-12 23:19 ` H. Peter Anvin
2006-07-13 11:15 ` Alan Cox
2006-07-14 18:45 ` Benjamin Herrenschmidt
2006-07-14 19:11 ` H. Peter Anvin
2006-07-12 21:29 ` H. Peter Anvin
2006-07-12 21:33 ` Michael Tokarev
2006-07-13 5:17 ` Ulrich Drepper
2006-07-13 6:27 ` Ian Wienand
2006-07-13 14:39 ` Eric W. Biederman
2006-07-13 15:05 ` Arjan van de Ven
-- strict thread matches above, loose matches on Subject: below --
2006-07-13 5:00 Albert Cahalan
2006-07-13 5:42 ` H. Peter Anvin
2006-07-13 6:09 ` Albert Cahalan
2006-07-13 6:13 ` Albert Cahalan
2006-07-13 6:38 ` Eric W. Biederman
2006-07-13 16:15 ` Albert Cahalan
2006-07-13 16:53 ` Eric W. Biederman
2006-07-13 17:06 ` Albert Cahalan
2006-07-13 15:20 ` Eric W. Biederman
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