On Mon, Oct 22, 2012 at 12:33:36PM +0200, Peter Zijlstra wrote: > On Mon, 2012-10-22 at 14:11 +0800, Yan, Zheng wrote: > > + /* LBR callstack does not work well with FREEZE_LBRS_ON_PMI */ > > + if (!cpuc->lbr_sel || !(cpuc->lbr_sel->config & LBR_CALL_STACK)) > > + debugctl |= DEBUGCTLMSR_FREEZE_LBRS_ON_PMI; > > How useful it is without this? How many calls between PMI and us getting > to intel_pmu_lbr_read()?
We use it only for ring 3. For ring 0 we assume frame pointer or dwarf information. So the CPL filter acts as the freeze. -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/
