On Fri, Mar 14, 2014 at 09:13:38AM +0100, Peter Zijlstra wrote: > On Thu, Mar 13, 2014 at 02:22:12PM -0700, Andi Kleen wrote: > > From: Andi Kleen <a...@linux.intel.com> > > > > The SDM forbids setting various event qualifiers with PEBS > > events. The magic cycles:pp event uses it, but it has caused > > problems in the past. We continue allowing it for cycles:pp, > > but forbid it for all other events to follow the SDM. > > Last time this came up I asked for what kind of problems it caused.
The original PEBS lockup on Sandy Bridge was caused by these bits. The person who architected the hardware strongly advised to not use them with PEBS events. Besides we do what the SDM tells us to do. Do you disagree with that? -Andi -- a...@linux.intel.com -- Speaking for myself only -- 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/