On Sat, 2013-12-07 at 06:20 +0100, Andi Kleen wrote: > On Sat, Dec 07, 2013 at 05:57:32AM +0100, Mike Galbraith wrote: > > On Fri, 2013-12-06 at 16:46 -0800, Andi Kleen wrote: > > > From: Andi Kleen <a...@linux.intel.com> > > > > > > This patch creates 4 new trace points: one at the beginning of idle, > > > one before entering mwait, one after exiting mwait, and one after > > > finishing the idle code. This is useful to trace down any > > > additional latencies caused by the ever-growing idle code. > > > > > > Idle latencies are a common source of performance problems, so it's > > > important to be able to measure them. > > > > You mean stuff like.. oh, say 60 cores doing zero work every 12ms > > munching ~20% cpu? > > Well that one is obvious. I mean more the subtle problems.
Yeah, not subtle. SGI could use C2 as power supply stress tester. -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/
