On Wed, 2013-12-11 at 13:43 +0100, Peter Zijlstra wrote: > On Wed, Dec 11, 2013 at 01:29:15PM +0100, Mike Galbraith wrote: > > On Wed, 2013-12-11 at 12:52 +0100, Peter Zijlstra wrote: > > > On Wed, Dec 11, 2013 at 12:38:39PM +0100, Borislav Petkov wrote: > > > > Right, if it turns out that this is really the case and that this > > > > erratum hasn't been fixed for models later than 29 - we'd need the > > > > additional model numbers to set X86_FEATURE_CLFLUSH_MONITOR correctly. > > > > > > You also need: https://lkml.org/lkml/2013/11/19/143 > > > > > > Because obviously not all mwait idle loops check that cpu bit. > > > > I had tried that patch, to see if it would magically make the thing > > start working, nope. I had also tried... > > > + if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) > > + clflush((void *)¤t_thread_info()->flags); > > Yeah, you need a bit extra to enable that feature bit for your CPU as > bpetkov said.
Works for me, one more for the stable bucket. So as soon as Len resurrects mwait_idle for Q6600 (and other core2 when booted max_cstates=1 so tsc clocksource is used instead of pos hpet), all the (known) idle regressions should be history. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
