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| author | Tejun Heo <tj@kernel.org> | 2023-05-18 06:02:08 +0300 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-05-18 06:02:08 +0300 |
| commit | 725e8ec59c56c65fb92e343c10a8842cd0d4f194 (patch) | |
| tree | b357ac51c47bdc4c24f87090a0d2191a84419b81 /Documentation/core-api | |
| parent | 854f5cc5b7355ceebf2bdfed97ea8f3c5d47a0c3 (diff) | |
| download | linux-725e8ec59c56c65fb92e343c10a8842cd0d4f194.tar.xz | |
workqueue: Add pwq->stats[] and a monitoring script
Currently, the only way to peer into workqueue operations is through
tracing. While possible, it isn't easy or convenient to monitor
per-workqueue behaviors over time this way. Let's add pwq->stats[] that
track relevant events and a drgn monitoring script -
tools/workqueue/wq_monitor.py.
It's arguable whether this needs to be configurable. However, it currently
only has several counters and the runtime overhead shouldn't be noticeable
given that they're on pwq's which are per-cpu on per-cpu workqueues and
per-numa-node on unbound ones. Let's keep it simple for the time being.
v2: Patch reordered to earlier with fewer fields. Field will be added back
gradually. Help message improved.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Diffstat (limited to 'Documentation/core-api')
| -rw-r--r-- | Documentation/core-api/workqueue.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/core-api/workqueue.rst b/Documentation/core-api/workqueue.rst index 8ec4d6270b24..7e5c39310bbf 100644 --- a/Documentation/core-api/workqueue.rst +++ b/Documentation/core-api/workqueue.rst @@ -348,6 +348,37 @@ Guidelines level of locality in wq operations and work item execution. +Monitoring +========== + +Use tools/workqueue/wq_monitor.py to monitor workqueue operations: :: + + $ tools/workqueue/wq_monitor.py events + total infl CMwake mayday rescued + events 18545 0 5 - - + events_highpri 8 0 0 - - + events_long 3 0 0 - - + events_unbound 38306 0 - - - + events_freezable 0 0 0 - - + events_power_efficient 29598 0 0 - - + events_freezable_power_ 10 0 0 - - + sock_diag_events 0 0 0 - - + + total infl CMwake mayday rescued + events 18548 0 5 - - + events_highpri 8 0 0 - - + events_long 3 0 0 - - + events_unbound 38322 0 - - - + events_freezable 0 0 0 - - + events_power_efficient 29603 0 0 - - + events_freezable_power_ 10 0 0 - - + sock_diag_events 0 0 0 - - + + ... + +See the command's help message for more info. + + Debugging ========= @@ -387,6 +418,7 @@ the stack trace of the offending worker thread. :: The work item's function should be trivially visible in the stack trace. + Non-reentrance Conditions ========================= |