Messages in this thread | | | Date | Wed, 7 Sep 2005 22:47:56 +0530 | From | Srivatsa Vaddagiri <> | Subject | Re: [PATCH 1/3] dynticks - implement no idle hz for x86 |
| |
On Wed, Sep 07, 2005 at 09:42:24AM -0700, Nish Aravamudan wrote: > Hrm, got dropped from the Cc... :) Yes, the dynamic-tick generic > infrastructure being proposed, with the idle CPU mask and the > set_all_cpus_idle() tick_source hook, would allow exactly this in > arch-specific code.
I think Bill is referring to the "resume" interface i.e an unset_all_cpus_idle() interface, which is missing (set/unset probably are not good prefixes maybe?). I feel we can add one.
> Is there a generic location where the all-idle state is entered?
Should be from the place where the last cpu is set in the bitmap and bitmap is found equal to cpu_online_map.
> Currently, I think we can do it via the generic reprogram() routine > checking the mask and then calling set_all_cpus_idle(), if > appropriate, after reprogramming the last idle CPU.
So are you saying that setting of the CPU in the bitmap will be done inside reprogram_timer routine? If we consider that reprogram_timer can directly point to a routine in a interrupt source file (like apic.c/timer_pit.c) I dont think that it is the right place to set bits in the nohz_cpu_mask. It can be done by the callee of reprogram_timer itself.
--
Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017 - 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/
| |