aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/workqueue.c
diff options
context:
space:
mode:
authorArjan van de Ven <arjan@linux.intel.com>2010-08-21 13:07:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-21 13:19:37 -0700
commite36c886a0f9d624377977fa6cae309cfd7f362fa (patch)
treef75e7c3e50a48c671ed4dff33103f601a2204af9 /kernel/workqueue.c
parent69b26c7ad00fd5b6129400725e2ffb95134a0e1b (diff)
workqueue: Add basic tracepoints to track workqueue execution
With the introduction of the new unified work queue thread pools, we lost one feature: It's no longer possible to know which worker is causing the CPU to wake out of idle. The result is that PowerTOP now reports a lot of "kworker/a:b" instead of more readable results. This patch adds a pair of tracepoints to the new workqueue code, similar in style to the timer/hrtimer tracepoints. With this pair of tracepoints, the next PowerTOP can correctly report which work item caused the wakeup (and how long it took): Interrupt (43) i915 time 3.51ms wakeups 141 Work ieee80211_iface_work time 0.81ms wakeups 29 Work do_dbs_timer time 0.55ms wakeups 24 Process Xorg time 21.36ms wakeups 4 Timer sched_rt_period_timer time 0.01ms wakeups 1 Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2994a0e3a61..8bd600c020e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -35,6 +35,9 @@
#include <linux/lockdep.h>
#include <linux/idr.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/workqueue.h>
+
#include "workqueue_sched.h"
enum {
@@ -1790,7 +1793,13 @@ static void process_one_work(struct worker *worker, struct work_struct *work)
work_clear_pending(work);
lock_map_acquire(&cwq->wq->lockdep_map);
lock_map_acquire(&lockdep_map);
+ trace_workqueue_execute_start(work);
f(work);
+ /*
+ * While we must be careful to not use "work" after this, the trace
+ * point will only record its address.
+ */
+ trace_workqueue_execute_end(work);
lock_map_release(&lockdep_map);
lock_map_release(&cwq->wq->lockdep_map);