From: Andi Kleen <ak@suse.de>
To: john stultz <johnstul@us.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>, linux-arch@vger.kernel.org
Subject: Re: Request for feedback on Generic Timeofday Subsystem (B20)
Date: Thu, 9 Mar 2006 19:18:00 +0100 [thread overview]
Message-ID: <200603091918.01155.ak@suse.de> (raw)
In-Reply-To: <1141953314.20123.110.camel@cog.beaverton.ibm.com>
On Friday 10 March 2006 02:15, john stultz wrote:
> On an x86-64 AMD server using nopmtimer/clocksource=tsc:
> mainline vs TOD
> gettimeofday(): 74.2%
> clock_gettime(CLOCK_MONOTONIC): 77.4%
> clock_gettime(CLOCK_REALTIME): 71.6%
>
> Hmmmm. I'm heading out of town for the weekend in a few moments, and I'd
> really like to re-verify those numbers, but yea, that's a 25%
> improvement. Might be too good to be true, but that should get Andi's
> attention :)
What is clocksource=tsc? It doesn't exist on 64bit kernels. And what are the absolute
numbers?
And clock_gettime uses a completely different path from gettimeofday so if they
have the same percentage your results look somewhat suspicious.
-Andi
next prev parent reply other threads:[~2006-03-10 1:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-06 20:15 Request for feedback on Generic Timeofday Subsystem (B20) Luck, Tony
2006-03-07 1:35 ` john stultz
2006-03-07 19:06 ` Luck, Tony
2006-03-07 19:37 ` john stultz
2006-03-07 22:40 ` Luck, Tony
2006-03-07 23:01 ` john stultz
2006-03-08 21:33 ` Luck, Tony
2006-03-10 1:15 ` john stultz
2006-03-09 18:18 ` Andi Kleen [this message]
2006-03-18 0:35 ` john stultz
-- strict thread matches above, loose matches on Subject: below --
2006-03-06 18:01 john stultz
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