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To: Alexey Dokuchaev <danfe@FreeBSD.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Thu, 07 Dec 2006 14:43:57 GMT."
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Date: Thu, 07 Dec 2006 22:39:59 +0000
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Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/kern kern_synch.c 
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In message <20061207144356.GB14587@FreeBSD.org>, Alexey Dokuchaev writes:
>On Thu, Nov 30, 2006 at 08:27:38AM +0000, Poul-Henning Kamp wrote:
>> phk         2006-11-30 08:27:38 UTC
>> 
>>   FreeBSD src repository
>> 
>>   Modified files:
>>     sys/kern             kern_synch.c 
>>   Log:
>>   Only grab the sched_lock if we actually need to modify the thread priority.
>>   
>>   During a buildworld only 2/3 of the calls to msleep actually changed
>>   the priority.
>
>Did you, by chance, have any benchmarks on this?

I didn't have time to do precise benchmarks and it wasn't statistically
significant in imprecise ones.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.