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Commit 339f7c90 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf_counter: PERF_RECORD_TIME 



By popular request, provide means to log a timestamp along with the
counter overflow event.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094518.024173282@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ebb3c4c4

include/linux/perf_counter.h

+2 −0
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ enum perf_counter_record_format { 
	PERF_RECORD_TID		= 1U << 1,

	PERF_RECORD_GROUP	= 1U << 2,

	PERF_RECORD_CALLCHAIN	= 1U << 3,

	PERF_RECORD_TIME	= 1U << 4,

};



/*
@@ -221,6 +222,7 @@ enum perf_event_type { 
	__PERF_EVENT_TID		= PERF_RECORD_TID,

	__PERF_EVENT_GROUP		= PERF_RECORD_GROUP,

	__PERF_EVENT_CALLCHAIN		= PERF_RECORD_CALLCHAIN,

	__PERF_EVENT_TIME		= PERF_RECORD_TIME,

};



#ifdef __KERNEL__

kernel/perf_counter.c

+14 −0
Original line number Diff line number Diff line
@@ -1826,6 +1826,7 @@ static void perf_counter_output(struct perf_counter *counter, 
	} group_entry;

	struct perf_callchain_entry *callchain = NULL;

	int callchain_size = 0;

	u64 time;



	header.type = PERF_EVENT_COUNTER_OVERFLOW;

	header.size = sizeof(header);
@@ -1862,6 +1863,16 @@ static void perf_counter_output(struct perf_counter *counter, 
		}

	}



	if (record_type & PERF_RECORD_TIME) {

		/*

		 * Maybe do better on x86 and provide cpu_clock_nmi()

		 */

		time = sched_clock();



		header.type |= __PERF_EVENT_TIME;

		header.size += sizeof(u64);

	}



	ret = perf_output_begin(&handle, counter, header.size, nmi);

	if (ret)

		return;
@@ -1895,6 +1906,9 @@ static void perf_counter_output(struct perf_counter *counter, 
	if (callchain)

		perf_output_copy(&handle, callchain, callchain_size);



	if (record_type & PERF_RECORD_TIME)

		perf_output_put(&handle, time);



	perf_output_end(&handle);

}