> The reason why using LBR call stack mode is restricted to user level > only is because of > a bug in the LBR call stack hardware which forces the kernel to drop > LBR_FREEZE_PMI.
It works with PEBS events, just not with non PEBS (the patch currently does not implement this distinction and I'm not sure it's worth it) > In other words ,the LBR does not stop on counter overflow, thus it > will be wiped out by > execution of kernel code leading to the PMU interrupt handler. It stops, but it takes some time to stop so the call-return stack can get out of sync. -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/
