sched: add tracepoints related to NUMA task migration
This patch adds three tracepoints
o trace_sched_move_numa when a task is moved to a node
o trace_sched_swap_numa when a task is swapped with another task
o trace_sched_stick_numa when a numa-related migration fails
The tracepoints allow the NUMA scheduler activity to be monitored and the
following high-level metrics can be calculated
o NUMA migrated stuck nr trace_sched_stick_numa
o NUMA migrated idle nr trace_sched_move_numa
o NUMA migrated swapped nr trace_sched_swap_numa
o NUMA local swapped trace_sched_swap_numa src_nid == dst_nid (should never happen)
o NUMA remote swapped trace_sched_swap_numa src_nid != dst_nid (should == NUMA migrated swapped)
o NUMA group swapped trace_sched_swap_numa src_ngid == dst_ngid
Maybe a small number of these are acceptable
but a high number would be a major surprise.
It would be even worse if bounces are frequent.
o NUMA avg task migs. Average number of migrations for tasks
o NUMA stddev task mig Self-explanatory
o NUMA max task migs. Maximum number of migrations for a single task
In general the intent of the tracepoints is to help diagnose problems
where automatic NUMA balancing appears to be doing an excessive amount
of useless work.
[akpm@linux-foundation.org: remove semicolon-after-if, repair coding-style]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 04c3084..67e1bbf 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -443,6 +443,93 @@
);
#endif /* CONFIG_DETECT_HUNG_TASK */
+DECLARE_EVENT_CLASS(sched_move_task_template,
+
+ TP_PROTO(struct task_struct *tsk, int src_cpu, int dst_cpu),
+
+ TP_ARGS(tsk, src_cpu, dst_cpu),
+
+ TP_STRUCT__entry(
+ __field( pid_t, pid )
+ __field( pid_t, tgid )
+ __field( pid_t, ngid )
+ __field( int, src_cpu )
+ __field( int, src_nid )
+ __field( int, dst_cpu )
+ __field( int, dst_nid )
+ ),
+
+ TP_fast_assign(
+ __entry->pid = task_pid_nr(tsk);
+ __entry->tgid = task_tgid_nr(tsk);
+ __entry->ngid = task_numa_group_id(tsk);
+ __entry->src_cpu = src_cpu;
+ __entry->src_nid = cpu_to_node(src_cpu);
+ __entry->dst_cpu = dst_cpu;
+ __entry->dst_nid = cpu_to_node(dst_cpu);
+ ),
+
+ TP_printk("pid=%d tgid=%d ngid=%d src_cpu=%d src_nid=%d dst_cpu=%d dst_nid=%d",
+ __entry->pid, __entry->tgid, __entry->ngid,
+ __entry->src_cpu, __entry->src_nid,
+ __entry->dst_cpu, __entry->dst_nid)
+);
+
+/*
+ * Tracks migration of tasks from one runqueue to another. Can be used to
+ * detect if automatic NUMA balancing is bouncing between nodes
+ */
+DEFINE_EVENT(sched_move_task_template, sched_move_numa,
+ TP_PROTO(struct task_struct *tsk, int src_cpu, int dst_cpu),
+
+ TP_ARGS(tsk, src_cpu, dst_cpu)
+);
+
+DEFINE_EVENT(sched_move_task_template, sched_stick_numa,
+ TP_PROTO(struct task_struct *tsk, int src_cpu, int dst_cpu),
+
+ TP_ARGS(tsk, src_cpu, dst_cpu)
+);
+
+TRACE_EVENT(sched_swap_numa,
+
+ TP_PROTO(struct task_struct *src_tsk, int src_cpu,
+ struct task_struct *dst_tsk, int dst_cpu),
+
+ TP_ARGS(src_tsk, src_cpu, dst_tsk, dst_cpu),
+
+ TP_STRUCT__entry(
+ __field( pid_t, src_pid )
+ __field( pid_t, src_tgid )
+ __field( pid_t, src_ngid )
+ __field( int, src_cpu )
+ __field( int, src_nid )
+ __field( pid_t, dst_pid )
+ __field( pid_t, dst_tgid )
+ __field( pid_t, dst_ngid )
+ __field( int, dst_cpu )
+ __field( int, dst_nid )
+ ),
+
+ TP_fast_assign(
+ __entry->src_pid = task_pid_nr(src_tsk);
+ __entry->src_tgid = task_tgid_nr(src_tsk);
+ __entry->src_ngid = task_numa_group_id(src_tsk);
+ __entry->src_cpu = src_cpu;
+ __entry->src_nid = cpu_to_node(src_cpu);
+ __entry->dst_pid = task_pid_nr(dst_tsk);
+ __entry->dst_tgid = task_tgid_nr(dst_tsk);
+ __entry->dst_ngid = task_numa_group_id(dst_tsk);
+ __entry->dst_cpu = dst_cpu;
+ __entry->dst_nid = cpu_to_node(dst_cpu);
+ ),
+
+ TP_printk("src_pid=%d src_tgid=%d src_ngid=%d src_cpu=%d src_nid=%d dst_pid=%d dst_tgid=%d dst_ngid=%d dst_cpu=%d dst_nid=%d",
+ __entry->src_pid, __entry->src_tgid, __entry->src_ngid,
+ __entry->src_cpu, __entry->src_nid,
+ __entry->dst_pid, __entry->dst_tgid, __entry->dst_ngid,
+ __entry->dst_cpu, __entry->dst_nid)
+);
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */