Date: Tue, 17 Jul 2007 13:53:16 -0500 From: Matt <datahead4@gmail.com> To: "Jeff Roberson" <jroberson@chesapeake.net> Cc: lveax <lveax.m@gmail.com>, current@freebsd.org, Claus Guttesen <kometen@gmail.com> Subject: Re: ULE/SCHED_SMP diff for 7.0, buildkernel & thanks. Message-ID: <cd6b4a5b0707171153u5cafe636o396922cfe38869a0@mail.gmail.com> In-Reply-To: <20070717114147.J92541@10.0.0.1> References: <20070716233030.D92541@10.0.0.1> <b41c75520707170318r2152b9f0l8d2ec7ea592fe450@mail.gmail.com> <469CACEC.1000103@freebsd.org> <b41c75520707170618o4106de94g57e60d2c93a68329@mail.gmail.com> <576dcbc20707170624kb671fe4ia5ddac21af93eccd@mail.gmail.com> <b41c75520707170636u116aa48fr99dfacc11945c922@mail.gmail.com> <20070717114147.J92541@10.0.0.1>
index | next in thread | previous in thread | raw e-mail
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 > > 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" > > > _______________________________________________ > 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" > Patch applied to my i386 CURRENT system with sources checked out today. Everything compiled cleanly and system has been running well since then.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?cd6b4a5b0707171153u5cafe636o396922cfe38869a0>