Messages in this thread | | | From | Nikhil Rao <> | Date | Tue, 28 Sep 2010 14:15:42 -0700 | Subject | Re: [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential |
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On Tue, Sep 28, 2010 at 6:57 AM, Mike Galbraith <efault@gmx.de> wrote: > On Mon, 2010-09-27 at 17:29 -0700, Nikhil Rao wrote: >> Hi all, >> >> I have attached a series of patches that improve load balancing when there is a >> large weight differential between tasks. These patches are based off the >> feedback Peter Zijlstra gave in an earlier post (see http://thread.gmane.org/gmane.linux.kernel/1015966). >> They can be applied to v2.6.36-rc5 or -tip without conflicts. >> >> Tested with the following setup. >> - Test machine is a 16 cpu box (quad-socket, quad-core). >> - Baseline is v2.6.36-rc5 kernel >> >> We spawn 16 SCHED_IDLE soaker threads and one SCHED_NORMAL task. On the >> baseline kernel, the machine has ~18% idle time. With these patches applied on >> top of baseline, idle time drops to 0%. > > Hm. I can get it stuck with one core idle on ym little quad. > > top - 15:53:22 up 11 min, 17 users, load average: 5.05, 4.40, 2.51 > Tasks: 270 total, 7 running, 263 sleeping, 0 stopped, 0 zombie > Cpu(s): 75.3%us, 0.0%sy, 0.0%ni, 24.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND > 7455 root 5 -15 7996 340 256 R 100 0.0 0:59.93 1 pert > 7421 root 20 0 7996 340 256 R 50 0.0 4:20.01 3 pert > 7422 root 20 0 7996 340 256 R 50 0.0 3:45.81 2 pert > 7423 root 20 0 7996 340 256 R 50 0.0 4:09.45 2 pert > 7424 root 20 0 7996 344 256 R 50 0.0 4:12.75 3 pert > >
Mike,
Thanks for running this. I've not been able to reproduce what you are seeing on the few test machines that I have (different combinations of MC, CPU and NODE domains). Can you please give me more info about your setup?
-Thanks, Nikhil -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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