sched/debug: Fix /proc/sched_debug regression (9c572591) · Commits · 戴 / test

Commit: ("sched/debug: Make schedstats a runtime tunable that is disabled by default") ... introduced a bug when CONFIG_SCHEDSTATS is enabled and the runtime tunable is disabled (which is the default). The wait-time, sum-exec, and sum-sleep fields are missing from the /proc/sched_debug file in the runnable_tasks section. Fix it with a new schedstat_val() macro which returns the field value when schedstats is enabled and zero otherwise. The macro works with both SCHEDSTATS and !SCHEDSTATS. I put the macro in stats.h since it might end up being useful in other places. Signed-off-by:

Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:

Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: ("sched/debug: Make schedstats a runtime tunable that is disabled by default") Link: http://lkml.kernel.org/r/bcda7c2790cf2ccbe586a28c02dd7b6fe7749a2b.1464994423.git.jpoimboe@redhat.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/sched/debug.c

+4 −11

Original line number	Diff line number	Diff line
		@@ -427,19 +427,12 @@ print_task(struct seq_file m, struct rq rq, struct task_struct *p)
		SPLIT_NS(p->se.vruntime),
		(long long)(p->nvcsw + p->nivcsw),
		p->prio);
		#ifdef CONFIG_SCHEDSTATS
		if (schedstat_enabled()) {
		SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
		SPLIT_NS(p->se.statistics.wait_sum),
		SPLIT_NS(p->se.sum_exec_runtime),
		SPLIT_NS(p->se.statistics.sum_sleep_runtime));
		}
		#else

		SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
		0LL, 0L,
		SPLIT_NS(schedstat_val(p, se.statistics.wait_sum)),
		SPLIT_NS(p->se.sum_exec_runtime),
		0LL, 0L);
		#endif
		SPLIT_NS(schedstat_val(p, se.statistics.sum_sleep_runtime)));

		#ifdef CONFIG_NUMA_BALANCING
		SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
		#endif

kernel/sched/stats.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,8 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
		# define schedstat_inc(rq, field) do { if (schedstat_enabled()) { (rq)->field++; } } while (0)
		# define schedstat_add(rq, field, amt) do { if (schedstat_enabled()) { (rq)->field += (amt); } } while (0)
		# define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
		# define schedstat_val(rq, field) ((schedstat_enabled()) ? (rq)->field : 0)

		#else /* !CONFIG_SCHEDSTATS */
		static inline void
		rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
		@@ -47,6 +49,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
		# define schedstat_inc(rq, field) do { } while (0)
		# define schedstat_add(rq, field, amt) do { } while (0)
		# define schedstat_set(var, val) do { } while (0)
		# define schedstat_val(rq, field) 0
		#endif

		#ifdef CONFIG_SCHED_INFO

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