From: Andi Kleen <ak@suse.de>
To: john stultz <johnstul@us.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] linux-2.5.59_getcycles_A0
Date: 07 Feb 2003 22:19:01 +0100 [thread overview]
Message-ID: <p73ptq3bxh6.fsf@oldwotan.suse.de> (raw)
In-Reply-To: john stultz's message of "7 Feb 2003 21:31:51 +0100"
john stultz <johnstul@us.ibm.com> writes:
> Joel, All,
>
> This patch moves the get_cycles() implementation into the timer_opts
> subsystem. This patch corrects issues between the hangcheck-timer code
> and systems running with timer_cyclone. As an extra bonus, it removes
> the CONFIG_X86_TSC #ifdef in get_cycles replacing it with
> timer->get_cycles().
>
> Comments flames and suggestions welcome.
Is this really a good idea? get_cycles is normally not used to get accurate
time, but just to get random numbers for /dev/random or quickly estimate
some code (scheduler used to use it for that). I think the TSC even when
unsynchronized is better for that than an external timer which potentially
lower resolution and long access time.
If you really added it I would at least change the random device to
use the old macro.
-Andi
next parent reply other threads:[~2003-02-07 21:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1044649542.18673.20.camel@w-jstultz2.beaverton.ibm.com.suse.lists.linux.kernel>
2003-02-07 21:19 ` Andi Kleen [this message]
2003-02-07 23:09 ` [RFC][PATCH] linux-2.5.59_getcycles_A0 john stultz
2003-02-08 0:18 ` Andi Kleen
2003-02-08 0:50 ` john stultz
2003-02-08 1:52 ` Andi Kleen
2003-02-08 1:57 ` Martin J. Bligh
2003-02-08 2:14 ` john stultz
2003-02-08 2:29 ` Andi Kleen
2003-02-08 2:42 ` john stultz
2003-02-08 3:41 ` Andi Kleen
2003-02-10 22:06 ` Bill Davidsen
2003-02-07 20:25 john stultz
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