Re: [PATCH v2] perf/core: Add support for PMUs that can be read from more than 1 CPU

2018-03-05 Thread Saravana Kannan
On 03/05/2018 04:17 AM, Mark Rutland wrote: On Fri, Mar 02, 2018 at 05:14:53PM -0800, Saravana Kannan wrote: Some PMUs events can be read from more than the one CPU. So allow the PMU driver to mark events as such. For these events, we don't need to reject reads or make smp calls to the event's C

Re: [PATCH v2] perf/core: Add support for PMUs that can be read from more than 1 CPU

2018-03-05 Thread Saravana Kannan
On 03/05/2018 04:21 AM, Mark Rutland wrote: On Mon, Mar 05, 2018 at 12:17:02PM +, Mark Rutland wrote: On Fri, Mar 02, 2018 at 05:14:53PM -0800, Saravana Kannan wrote: @@ -629,6 +629,7 @@ struct perf_event { int oncpu; int

Re: [PATCH v2] perf/core: Add support for PMUs that can be read from more than 1 CPU

2018-03-05 Thread Mark Rutland
On Mon, Mar 05, 2018 at 12:17:02PM +, Mark Rutland wrote: > On Fri, Mar 02, 2018 at 05:14:53PM -0800, Saravana Kannan wrote: > > @@ -629,6 +629,7 @@ struct perf_event { > > > > int oncpu; > > int cpu; > > + cpumask_t

Re: [PATCH v2] perf/core: Add support for PMUs that can be read from more than 1 CPU

2018-03-05 Thread Mark Rutland
On Fri, Mar 02, 2018 at 05:14:53PM -0800, Saravana Kannan wrote: > Some PMUs events can be read from more than the one CPU. So allow the > PMU driver to mark events as such. For these events, we don't need to > reject reads or make smp calls to the event's CPU (and cause > unnecessary overhead and

[PATCH v2] perf/core: Add support for PMUs that can be read from more than 1 CPU

2018-03-02 Thread Saravana Kannan
Some PMUs events can be read from more than the one CPU. So allow the PMU driver to mark events as such. For these events, we don't need to reject reads or make smp calls to the event's CPU (and cause unnecessary overhead and wake ups). When a PMU driver marks an event as such, care must be taken