Date: Tue, 17 Jul 2007 21:56:29 -0700 From: Garrett Cooper <youshi10@u.washington.edu> To: Attilio Rao <attilio@freebsd.org> Cc: current@freebsd.org Subject: Re: ULE/SCHED_SMP diff for 7.0, buildkernel & thanks. Message-ID: <469D9D7D.3040600@u.washington.edu> In-Reply-To: <Pine.LNX.4.43.0707171241580.17139@hymn01.u.washington.edu> References: <Pine.LNX.4.43.0707171241580.17139@hymn01.u.washington.edu>
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youshi10@u.washington.edu wrote: > On Tue, 17 Jul 2007, Attilio Rao wrote: > >> 2007/7/17, Abdullah Ibn Hamad Al-Marri <almarrie@gmail.com>: >>> On 7/17/07, Jeff Roberson <jroberson@chesapeake.net> wrote: >>> > 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 >>> >>> Did you compare it to latest Linux fixes? is FreeBSD + ULE + MySQL >>> still faster than linux? >> >> Just look at the link Jeff posted, it seems very well explaining :). >> >> Attilio >> >> >> -- >> Peace can only be achieved by understanding - A. Einstein > > Unfortunately those results are still based on 2.6.20, not 2.6.22 (2 > minor patch revision difference). > > I assume that that's for a vanilla Linux kernel? > > -Garrett Scratch my earlier comment about it works just fine. I seem to have broken my VM again, but it took 5+something iterations this round to get it to break. Now I have to restart Windows because of the random instabilities :). -Garrett
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