On Thu, Mar 03, 2016 at 03:40:49PM -0800, Stephane Eranian wrote: > On Thu, Mar 3, 2016 at 1:43 PM, Andi Kleen <[email protected]> wrote: > > > > > + /* > > > + * 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. > > I understand that. You mean I need to that has all the bits that were set to > call intel_pmu_ack_status(). > > But if you look at the code, and where I made the change, there is no more > intel_pmu_ack_status() BEFORE you read the status again via > intel_pmu_get_status(). > > So why would I need to keep another variable around?
I suspect Andi is having something along: lkml.kernel.org/r/[email protected] applied to his tree.
