Commit 3786310a authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

perf sched: Add max delay time snapshot 



When we have a maximum latency reported for a task, we need a
convenient way to find the matching location to the raw traces
or to perf sched map that shows where the task has been
eventually scheduled in. This gives a pointer to retrieve the
events that occured during this max latency.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260391208-6808-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 5660ce34

tools/perf/builtin-sched.c

+10 −6
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ struct work_atoms { 
	struct thread		*thread;

	struct rb_node		node;

	u64			max_lat;

	u64			max_lat_at;

	u64			total_lat;

	u64			nb_atoms;

	u64			total_runtime;
@@ -1013,8 +1014,10 @@ add_sched_in_event(struct work_atoms *atoms, u64 timestamp) 


	delta = atom->sched_in_time - atom->wake_up_time;

	atoms->total_lat += delta;

	if (delta > atoms->max_lat)

	if (delta > atoms->max_lat) {

		atoms->max_lat = delta;

		atoms->max_lat_at = timestamp;

	}

	atoms->nb_atoms++;

}
@@ -1210,10 +1213,11 @@ static void output_lat_thread(struct work_atoms *work_list) 


	avg = work_list->total_lat / work_list->nb_atoms;



	printf("|%11.3f ms |%9llu | avg:%9.3f ms | max:%9.3f ms |\n",

	printf("|%11.3f ms |%9llu | avg:%9.3f ms | max:%9.3f ms | max at: %9.6f s\n",

	      (double)work_list->total_runtime / 1e6,

		 work_list->nb_atoms, (double)avg / 1e6,

		 (double)work_list->max_lat / 1e6);

		 (double)work_list->max_lat / 1e6,

		 (double)work_list->max_lat_at / 1e9);

}



static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
@@ -1704,9 +1708,9 @@ static void __cmd_lat(void) 
	read_events();

	sort_lat();



	printf("\n -----------------------------------------------------------------------------------------\n");

	printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms |\n");

	printf(" -----------------------------------------------------------------------------------------\n");

	printf("\n ---------------------------------------------------------------------------------------------------------------\n");

	printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms | Maximum delay at     |\n");

	printf(" ---------------------------------------------------------------------------------------------------------------\n");



	next = rb_first(&sorted_atom_root);

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