Messages in this thread |  | | | Subject | Re: specjbb2005 and aim7 regression with 2.6.32-rc kernels | | From | "Zhang, Yanmin" <> | | Date | Mon, 09 Nov 2009 14:19:57 +0800 |
On Fri, 2009-11-06 at 09:04 +0100, Ingo Molnar wrote: > * Zhang, Yanmin <yanmin_zhang@linux.intel.com> wrote: > > > Comparing with 2.6.31, specjbb2005 and aim7 have some regressions with > > 2.6.32-rc kernels on core2 machines. > > > > 1) On 4*4 core tigerton: specjbb2005 has about 5% regression. > > 2) On 2*4 stoakley: aim7 has about 5% regression. > > > > On Nehalem, specjbb2005 has about 2%~8% improvement instead of > > regression. > > > > aim7 has much dependency on schedule patameters, such like > > sched_latency_ns, sched_min_granularity_ns, and > > sched_wakeup_granularity_ns. 2.6.32-rc kernel decreases these > > parameter values. I restore them and retest aim7 on stoakley. aim7 > > regression becomes about 2% and specjbb2005 regression also becomes > > 2%. But on Nehalem, the improvement shrinks. > > Which precise 2.6.32-rc commit have you tested? > > Since v2.6.32-rc6 Linus's tree has this one too: > > f685cea: sched: Strengthen buddies and mitigate buddy induced latencies > > Which should improve things a bit. For 2.6.33 we have queued up these > two in -tip: > > a1f84a3: sched: Check for an idle shared cache in select_task_rq_fair() > 1b9508f: sched: Rate-limit newidle > > If any of them fixes a performance regression we could still merge them > into 2.6.32 as well. 1b9508f definitely fixes netperf UDP loopback regression.
Yanmin
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