Messages in this thread | | | Date | Tue, 29 Nov 2011 16:37:01 +0530 | From | Deepthi Dharwar <> | Subject | Re: Too many poll_idle cpu calls in kernel 3.2 rc-series |
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On 11/29/2011 02:14 AM, Andi Kleen wrote:
> On Mon, Nov 28, 2011 at 09:31:13PM +0100, Nicolas Kalkhof wrote: >> Andi, >> >> correct. The issue was introduced somewhere between 3.1 final and 3.2-rc1. I've tried to track down the bad commit but so far I haven't been successfull. The only workaround I found is to set the idle boot parameter to mwait and to disable CONFIG_INTEL_IDLE. Somehow the kernel seems to set idle to poll by default - no idea why :-(. I wonder if other mobile sandy bridge cpus are affected as well. > > There are only a few changesets affecting drivers/idle > > Can you try to git revert > > 46bcfad7a819bd17ac4e831b04405152d59784ab > 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2 > e978aa7d7d57d04eb5f88a7507c4fb98577def77 > > ? > > -Andi
Hi,
I am guessing that for workaround just setting the idle boot parameter to mwait should work. Have u tested this without disabling CONFIG_INTEL_IDLE ?
Also one thing to note from your logs is, cpu is not entering any of the other C states except for POLL. Can you also check if your are enabling only POLL for idle. I am able to enter deeper C-states on i5-2540M with Intel_Idle enabled.
Power top o/p: -------------
Core | CPU 0 CPU 1 POLL 0.0% | POLL 0.0% 0.0 ms 0.0% 0.0 ms C1-SNB 1.4% | C1-SNB 2.2% 0.7 ms 0.5% 0.9 ms C3-SNB 0.9% | C3-SNB 1.6% 1.2 ms 0.1% 1.2 ms C6-SNB 0.2% | C6-SNB 0.3% 1.6 ms 0.0% 0.9 ms C7-SNB 95.8% | C7-SNB 93.7% 3.7 ms 97.8% 15.1 ms
Regards, Deepthi
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