Messages in this thread | | | From | "Yu, Fenghua" <> | Subject | RE: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi | Date | Tue, 5 Jun 2012 16:18:35 +0000 |
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> From: Peter Zijlstra [mailto:peterz@infradead.org] > Sent: Tuesday, June 05, 2012 9:09 AM > To: Yu, Fenghua > Cc: Rusty Russell; Thomas Gleixner; Ingo Molnar; H Peter Anvin; Siddha, > Suresh B; Luck, Tony; Mallick, Asit K; Arjan Dan De Ven; linux-kernel; > x86; linux-pm; Srivatsa S. Bhat > Subject: RE: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait > or nmi > > On Tue, 2012-06-05 at 16:02 +0000, Yu, Fenghua wrote: > > > > Users can consolidate processes on a few online CPU's and offline the > > rest when workload is light. > > No they can't, hotplug is a root only op.
That's right. A root admin does this. Actually some Linux people are adjusting online/offline CPU's based on workload to save power in their business. There are some advantages for online/offline CPU's than idling CPU's.
> > > This consolidation can save more power and have better performance > > than idling CPU's because hot cache in online CPU's and offline CPU's > > can be allocated in same package. > > Yeah, or you fix the load-balancer to do this.
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