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Commit 477f00f9 authored by Kan Liang's avatar Kan Liang Committed by Ingo Molnar
Browse files

perf/x86/intel/ds: Extract code of event update in short period 



The drain_pebs() could be called twice in a short period for auto-reload
event in pmu::read(). The intel_pmu_save_and_restart_reload() should be
called to update the event->count.

This case should also be handled on Icelake. Extract the code for
later reuse.

Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-5-kan.liang@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 48f38aa4

arch/x86/events/intel/ds.c

+20 −13
Original line number Diff line number Diff line
@@ -1491,6 +1491,25 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) 
	__intel_pmu_pebs_event(event, iregs, at, top, 0, n);

}



static void intel_pmu_pebs_event_update_no_drain(struct cpu_hw_events *cpuc, int size)

{

	struct perf_event *event;

	int bit;



	/*

	 * The drain_pebs() could be called twice in a short period

	 * for auto-reload event in pmu::read(). There are no

	 * overflows have happened in between.

	 * It needs to call intel_pmu_save_and_restart_reload() to

	 * update the event->count for this case.

	 */

	for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled, size) {

		event = cpuc->events[bit];

		if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)

			intel_pmu_save_and_restart_reload(event, 0);

	}

}



static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)

{

	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
@@ -1518,19 +1537,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) 
	}



	if (unlikely(base >= top)) {

		/*

		 * The drain_pebs() could be called twice in a short period

		 * for auto-reload event in pmu::read(). There are no

		 * overflows have happened in between.

		 * It needs to call intel_pmu_save_and_restart_reload() to

		 * update the event->count for this case.

		 */

		for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled,

				 size) {

			event = cpuc->events[bit];

			if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)

				intel_pmu_save_and_restart_reload(event, 0);

		}

		intel_pmu_pebs_event_update_no_drain(cpuc, size);

		return;

	}