Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH] sched: Get rid of unnecessary checks from select_idle_sibling | Date | Thu, 10 Jan 2013 14:49:01 +0900 |
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Hi Preeti,
On Wed, 09 Jan 2013 13:51:00 +0530, Preeti U. Murthy wrote: > On 01/09/2013 12:20 PM, Namhyung Kim wrote: >> From: Namhyung Kim <namhyung.kim@lge.com> >> >> AFAICS @target cpu of select_idle_sibling() is always either prev_cpu >> or this_cpu. So no need to check it again and the conditionals can be >> consolidated. [snip] > If NUMA_TTWU_BIAS or NUMA_TTWU_TO is true(it is false by
I can't find those bits in the code. I've checked v3.8-rc2, next-20130110, tip/master and tip/numa/core but there's nothing like above. Which tree are you saying?
> default),cpu/prev_cpu can be changed to be a random node_cpu(the node > that 'this_cpu' is on). In which case even if the node cpu is idle,it > would not be a viable target,looks like.Maybe that is why > select_idle_sibling() makes the check if the target is prev_cpu/this cpu.
Looking into tip/numa/core, I can see that there's a code added for CONFIG_NUMA_BALANCING. But still, it seems nothing changed on a path from select_task_rq_fair() to select_idle_sibling() - i.e. if the select_idle_sibling called, the target would be either prev_cpu or this cpu. Am I missing something?
Thanks, Namhyung
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