Messages in this thread | | | Date | Tue, 11 Nov 2008 10:22:40 +0530 | From | Vaidyanathan Srinivasan <> | Subject | Re: [RFC PATCH v3 0/5] Tunable sched_mc_power_savings=n |
| |
* Peter Zijlstra <a.p.zijlstra@chello.nl> [2008-11-10 19:50:16]:
> > a quick response, I'll read them more carefully tomorrow:
Hi Peter,
Thanks for the quick review.
> > - why are the preferred cpu things pointers? afaict using just the cpu > number is both smaller and clearer to the reader.
I would need each cpu within a partitioned sched domain to point to the _same_ preferred wakeup cpu. The preferred CPU will be updated in one place in find_busiest_group() and used by wake_idle.
If I have a per cpu value, then updating it for each cpu in the partitioned sched domain will be slow.
The actual number of preferred_wakeup_cpu will be equal to the number of partitions. If there are no partitions in the sched domains, then then all per-cpu pointers will point to the same variable.
> - in patch 5/5 you do: > > + spin_unlock(&this_rq->lock); > + double_rq_lock(this_rq, busiest); > > we call that double_lock_balance()
Will fix this. Did not look for such a routine :)
> - comments go like: > > /* > * this is a multi- > * line comment > */
Will fix this too.
Thanks, Vaidy
| |