From owner-freebsd-current@FreeBSD.ORG Tue Jul 17 18:46:01 2007 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 138BB16A401 for ; Tue, 17 Jul 2007 18:46:01 +0000 (UTC) (envelope-from jroberson@chesapeake.net) Received: from webaccess-cl.virtdom.com (webaccess-cl.virtdom.com [216.240.101.25]) by mx1.freebsd.org (Postfix) with ESMTP id B8BE213C49D for ; Tue, 17 Jul 2007 18:46:00 +0000 (UTC) (envelope-from jroberson@chesapeake.net) Received: from [192.168.1.101] (c-71-231-138-78.hsd1.or.comcast.net [71.231.138.78]) (authenticated bits=0) by webaccess-cl.virtdom.com (8.13.6/8.13.6) with ESMTP id l6HIjwqQ020294 (version=TLSv1/SSLv3 cipher=DHE-DSS-AES256-SHA bits=256 verify=NO); Tue, 17 Jul 2007 14:45:59 -0400 (EDT) (envelope-from jroberson@chesapeake.net) Date: Tue, 17 Jul 2007 11:49:05 -0700 (PDT) From: Jeff Roberson X-X-Sender: jroberson@10.0.0.1 To: Claus Guttesen In-Reply-To: Message-ID: <20070717114147.J92541@10.0.0.1> References: <20070716233030.D92541@10.0.0.1> <469CACEC.1000103@freebsd.org> <576dcbc20707170624kb671fe4ia5ddac21af93eccd@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: lveax , current@freebsd.org Subject: Re: ULE/SCHED_SMP diff for 7.0, buildkernel & thanks. X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Jul 2007 18:46:01 -0000 With regards to buildkernel times; I do not want to sacrafice performance on other benchmarks to improve buildkernel. The problem is that 4BSD is as agressive as possible at scheduling work on idle cores. This behavior that helps one buildworld hurts on other, in my opinion, more important benchmarks. For example: http://people.freebsd.org/~jeff/sysbench.png ULE is 33% faster than SCHED_4BSD at this mysql test. This is a direct result of prefering to idle to make more efficient scheduling decisions. ULE is also faster at various networking benchmarks for similar reasons. I also believe that while the real time may be slower on buildworld the system and user time will be smaller by a degree greater than the delta in real time. This means that while you're building packages you have a little more cpu time leftover to handle other tasks. Furthermore, as the number of cores goes up things start to tip in favor of ULE although this is somewhat because it's harder for even 4BSD to keep them busy due to disk bandwidth. Thanks everyone for testing. Can someone confirm that they have tested with x86 rather than amd64? I will probably commit later today. Thanks, Jeff On Tue, 17 Jul 2007, Claus Guttesen wrote: >> > sched_ule: >> > >> > -j 3 buildkernel: 13:23 >> > -j 4 buildkernel: 12:38 >> > -j 5 buildkernel: 12:41 >> > -j 6 buildkernel: 12:47 >> > >> > sched_4bsd: >> > -j 3 buildkernel: 11:43 >> > -j 4 buildkernel: 12:02 >> > >> > So sched_ule seems to handle more processes slightly better than 4bsd >> > albeit it does it slower. ule's sweet spot is -j 4 and 4bsd is -j 3. >> > >> >> 4bsd vs ULE >> >> -j 3 buildkernel: 11:43 vs -j 3 buildkernel: 13:23 >> >> -j 4 buildkernel: 12:02 vs -j 4 buildkernel: 12:38 >> >> >> ULE is always slower? > > In my case yes. > > -- > regards > Claus > > When lenity and cruelty play for a kingdom, > the gentlest gamester is the soonest winner. > > Shakespeare > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >