Messages in this thread | | | Date | Thu, 3 Mar 2016 13:43:12 -0800 | From | Andi Kleen <> | Subject | Re: [PATCH 2/3] perf/x86/pebs: add workaround for broken OVFL status on HSW |
| |
> + /* > + * There are cases where, even though, the PEBS ovfl bit is set in > + * GLOBAL_OVF_STATUS, the PEBS events may also have their overflow bits > + * set for their counters. We must clear them here because they have > + * been processed as exact samples in the drain_pebs() routine. They > + * must not be processed again in the for_each_bit_set() loop for > + * regular samples below. > + */ > + status &= ~cpuc->pebs_enabled; > + status &= x86_pmu.intel_ctrl | GLOBAL_STATUS_TRACE_TOPAPMI;
If you just clear the bits here they will not be acked and stay around forever in GLOBAL_STATUS, which causes other problems.
You need a separate ack_status variable that contains all bits and is always acked.
-Andi -- ak@linux.intel.com -- Speaking for myself only
| |