On Wed, Oct 21, 2015 at 06:55:42PM +0200, Andi Kleen wrote: > On Wed, Oct 21, 2015 at 06:52:52PM +0200, Peter Zijlstra wrote: > > On Wed, Oct 21, 2015 at 08:26:08AM -0700, Andi Kleen wrote: > > > So it turns out that UOPS_RETIRED.ALL+pebs only works by accident > > > on Skylake. It's not in the specification. > > > > Accident or not, it works and you've tested it. Might as well keep it. > > Specs can be updated. > > No, it's better not to use it.
This is really rather unfortunate; what is the failure mode? > > Also, even with the SNB 'hickup' they still haven't got the memo that > > cycles is important for PEBS ? > > INST_RETIRED.PREC_DIST is a far better cycles than UOPS_RETIRED.ALL > (see my earlier example) If you only want the one counter, yes. And since you made me look at the SDM; it looks like our skl pebs table isn't anything like the table there. Also, do the events BR_INST_RETIRED have a composable umask? That is, .event=0xc4, .umask=41 is valid and would be 'conditional far branches'. The same would be true for the HSW/BDW table I suppose, the memops retired stuff looks composable but we currently do not allow that. -- 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/
