Messages in this thread | | | Date | Fri, 9 May 2014 19:02:34 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 6/8] sched,idle: Avoid spurious wakeup IPIs |
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On Fri, May 09, 2014 at 03:57:45PM +0100, Catalin Marinas wrote: > On Fri, May 09, 2014 at 03:50:02PM +0100, Peter Zijlstra wrote: > > On Fri, May 09, 2014 at 03:40:34PM +0100, Catalin Marinas wrote: > > > > > I wonder why we still need TIF_POLLING_NRFLAG for arm64. It was on arm > > > until commit 16a8016372c42c7628eb (sanitize tsk_is_polling()). On arm64 > > > we use wfi for idle or a firmware call but in both cases the assumption > > > is that we need an interrupt for waking up. > > > > > > So I think we should remove this macro for arm64. > > > > Does ARM64 support idle=poll? If so, you could keep it for that, > > otherwise it does indeed appear to be pointless. > > We don't support idle=poll either. > > > As to 32bit ARM, are there SMP chips which do not have WFI? > > No. WFI is even used for the secondary booting protocol (we need to send > an IPI to get them going).
OK, so I'll queue a patch removing TIF_POLLING_NRFLAG for arm64.
Thanks! [unhandled content-type:application/pgp-signature] | |