From bfe1fcd2688f557a6b6a88f59ea7619228728bd7 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 23 Jan 2015 18:45:46 +0000 Subject: perf/x86/intel: Support task events with Intel CQM Add support for task events as well as system-wide events. This change has a big impact on the way that we gather LLC occupancy values in intel_cqm_event_read(). Currently, for system-wide (per-cpu) events we defer processing to userspace which knows how to discard all but one cpu result per package. Things aren't so simple for task events because we need to do the value aggregation ourselves. To do this, we defer updating the LLC occupancy value in event->count from intel_cqm_event_read() and do an SMP cross-call to read values for all packages in intel_cqm_event_count(). We need to ensure that we only do this for one task event per cache group, otherwise we'll report duplicate values. If we're a system-wide event we want to fallback to the default perf_event_count() implementation. Refactor this into a common function so that we don't duplicate the code. Also, introduce PERF_TYPE_INTEL_CQM, since we need a way to track an event's task (if the event isn't per-cpu) inside of the Intel CQM PMU driver. This task information is only availble in the upper layers of the perf infrastructure. Other perf backends stash the target task in event->hw.*target so we need to do something similar. The task is used to determine whether events should share a cache group and an RMID. Signed-off-by: Matt Fleming Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Kanaka Juvva Cc: Linus Torvalds Cc: Vikas Shivappa Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/1422038748-21397-8-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ca5504c48f4f..dac4c2831d82 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -129,6 +129,7 @@ struct hw_perf_event { struct list_head cqm_events_entry; struct list_head cqm_groups_entry; struct list_head cqm_group_entry; + struct task_struct *cqm_target; }; #ifdef CONFIG_HAVE_HW_BREAKPOINT struct { /* breakpoint */ -- cgit v1.2.3