From: Andi Kleen Date: Fri, 6 Sep 2013 03:37:38 +0000 (-0700) Subject: perf/x86/intel: Avoid checkpointed counters causing excessive TSX aborts X-Git-Tag: omap-for-v3.13/fixes-for-merge-window-take2~41^2~47 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2dbf0116aa8c7bfa900352d3f7b2609748fcc1c5;p=pandora-kernel.git perf/x86/intel: Avoid checkpointed counters causing excessive TSX aborts With checkpointed counters there can be a situation where the counter is overflowing, aborts the transaction, is set back to a non overflowing checkpoint, causes interupt. The interrupt doesn't see the overflow because it has been checkpointed. This is then a spurious PMI, typically with a ugly NMI message. It can also lead to excessive aborts. Avoid this problem by: - Using the full counter width for counting counters (earlier patch) - Forbid sampling for checkpointed counters. It's not too useful anyways, checkpointing is mainly for counting. The check is approximate (to still handle KVM), but should catch the majority of cases. - On a PMI always set back checkpointed counters to zero. Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1378438661-24765-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed