Messages in this thread | | | Subject | Re: Idle loadavg of ~1, maybe MD related | From | Benjamin Herrenschmidt <> | Date | Sat, 05 Jan 2008 21:18:52 +1100 |
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On Sat, 2008-01-05 at 02:04 -0800, Robin H. Johnson wrote: > On Sat, Jan 05, 2008 at 01:30:37AM -0800, Andrew Morton wrote: > > >From that I'd suspect that kwindfarm is being a bad citizen. > > If a process is consistently stuck in D state, run > Windfarm.
It's an unfortunate artifact that kernel threads that do non-interruptible sleep are counted as load...
In the case of windfarm, it does a lot (a _LOT_) of accesses to various i2c busses and the SMU (the system management unit which controls the fans). All those are done in the form of short requests during which the process is doing a wait_for_completion() or similar.
I don't see a better way to do that, I think we could have good use of something that stops counting those in the load average...
Ben.
> > echo w > /proc/sysrq-trigger > > then record the resulting dmesg output so we can see where it got stuck. > > Traceback: > [552710.416174] SysRq : Show Blocked State > [552710.417876] task PC stack pid father > [552710.417888] kwindfarm D 0000000000000000 0 829 2 > [552710.417892] Call Trace: > [552710.417895] [c00000036c9835f0] [c000000000528b90] 0xc000000000528b90 (unreliable) > [552710.417908] [c00000036c9837c0] [c00000000000f4a8] .__switch_to+0xd8/0x110 > [552710.417985] [c00000036c983850] [c0000000003bb2a0] .schedule+0x62c/0x6c8 > [552710.417992] [c00000036c983940] [c0000000003bb8c4] .schedule_timeout+0x3c/0xe8 > [552710.417997] [c00000036c983a10] [c0000000003bb51c] .wait_for_common+0x100/0x1bc > [552710.418002] [c00000036c983ae0] [c000000000285300] .smu_fan_set+0x17c/0x1e4 > [552710.418009] [c00000036c983c30] [c000000000284078] .pm112_wf_notify+0xc50/0x12d0 > [552710.418015] [c00000036c983d20] [c0000000003bfb84] .notifier_call_chain+0x5c/0xcc > [552710.418021] [c00000036c983dc0] [c00000000006f4b4] .__blocking_notifier_call_chain+0x70/0xb0 > [552710.418027] [c00000036c983e70] [c000000000282d9c] .wf_thread_func+0x78/0x11c > [552710.418032] [c00000036c983f00] [c000000000069b00] .kthread+0x78/0xc4 > [552710.418039] [c00000036c983f90] [c000000000023d0c] .kernel_thread+0x4c/0x68 > [552710.418064] Sched Debug Version: v0.07, 2.6.24-rc6-prod-g6f0f5304 #10 > [552710.418067] now at 552723945.170635 msecs > [552710.418070] .sysctl_sched_latency : 60.000000 > [552710.418073] .sysctl_sched_min_granularity : 12.000000 > [552710.418076] .sysctl_sched_wakeup_granularity : 30.000000 > [552710.418079] .sysctl_sched_batch_wakeup_granularity : 30.000000 > [552710.418082] .sysctl_sched_child_runs_first : 0.000001 > [552710.418085] .sysctl_sched_features : 7 > > Full output at > http://dev.gentoo.org/~robbat2/20080105_windfarm_sysrq_w.txt >
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