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Commit b8efb561 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched debug: BKL usage statistics 



add per task and per rq BKL usage statistics.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent de8d585a

include/linux/sched.h

+4 −0
Original line number Diff line number Diff line
@@ -621,6 +621,10 @@ struct sched_info { 
	/* timestamps */

	unsigned long long last_arrival,/* when we last ran on a cpu */

			   last_queued;	/* when we were last queued to run */

#ifdef CONFIG_SCHEDSTATS

	/* BKL stats */

	unsigned long bkl_cnt;

#endif

};

#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */

kernel/sched.c

+9 −0
Original line number Diff line number Diff line
@@ -356,6 +356,9 @@ struct rq { 
	/* try_to_wake_up() stats */

	unsigned long ttwu_cnt;

	unsigned long ttwu_local;



	/* BKL stats */

	unsigned long bkl_cnt;

#endif

	struct lock_class_key rq_lock_key;

};
@@ -3414,6 +3417,12 @@ static inline void schedule_debug(struct task_struct *prev) 
	profile_hit(SCHED_PROFILING, __builtin_return_address(0));



	schedstat_inc(this_rq(), sched_cnt);

#ifdef CONFIG_SCHEDSTATS

	if (unlikely(prev->lock_depth >= 0)) {

		schedstat_inc(this_rq(), bkl_cnt);

		schedstat_inc(prev, sched_info.bkl_cnt);

	}

#endif

}



/*

kernel/sched_debug.c

+4 −0
Original line number Diff line number Diff line
@@ -136,6 +136,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) 
			SPLIT_NS(spread0));

	SEQ_printf(m, "  .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);

	SEQ_printf(m, "  .%-30s: %ld\n", "load", cfs_rq->load.weight);

	SEQ_printf(m, "  .%-30s: %ld\n", "bkl_cnt",

			rq->bkl_cnt);

}



static void print_cpu(struct seq_file *m, int cpu)
@@ -323,6 +325,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) 
	PN(se.exec_max);

	PN(se.slice_max);

	PN(se.wait_max);

	P(sched_info.bkl_cnt);

#endif

	SEQ_printf(m, "%-25s:%20Ld\n",

		   "nr_switches", (long long)(p->nvcsw + p->nivcsw));
@@ -350,6 +353,7 @@ void proc_sched_set_task(struct task_struct *p) 
	p->se.exec_max			= 0;

	p->se.slice_max			= 0;

	p->se.wait_max			= 0;

	p->sched_info.bkl_cnt		= 0;

#endif

	p->se.sum_exec_runtime		= 0;

	p->se.prev_sum_exec_runtime	= 0;