Messages in this thread |  | | Date | Sat, 25 Feb 2012 17:32:53 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] Extend mwait idle to optimize away CAL and RES interrupts to an idle CPU -v1 |
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On Fri, Feb 24, 2012 at 01:41:50PM +0800, Yong Zhang wrote: > On Thu, Feb 23, 2012 at 11:34:11AM -0800, Venki Pallipadi wrote: > > On Thu, Feb 23, 2012 at 1:30 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > > Why not scheduler_ipi()? > > > > Was trying to avoid irq_enter/exit. As the work here is done in idle > > thread context, I though we could avoid enter/exit. > > It seems we could not. > At least RCU need it, see commit c5d753a55, otherwise we will get > warning like 'RCU used illegally from extended quiescent state!'
If the use is tracing, then Steven Rostedt's patchset plus use of his _rcuidle() tracing variants handles this:
https://lkml.org/lkml/2012/2/7/231
If this is instead algorithmic use of RCU, a set of patches I have queued up for 3.4 will be required.
Thanx, Paul
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