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| author | Breno Leitao <leitao@debian.org> | 2026-03-05 08:15:40 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-03-05 07:30:11 -1000 |
| commit | 8823eaef45da7f156a1396f40d53b985c511edef (patch) | |
| tree | f9d22f2233198135e136030300be0a8eb3d8b581 /Documentation/console/git@git.tavy.me:linux.git | |
| parent | e8e14ac7cfe437b896838e7f7d07c573965b4e4e (diff) | |
workqueue: Show all busy workers in stall diagnostics
show_cpu_pool_hog() only prints workers whose task is currently running
on the CPU (task_is_running()). This misses workers that are busy
processing a work item but are sleeping or blocked — for example, a
worker that clears PF_WQ_WORKER and enters wait_event_idle(). Such a
worker still occupies a pool slot and prevents progress, yet produces
an empty backtrace section in the watchdog output.
This is happening on real arm64 systems, where
toggle_allocation_gate() IPIs every single CPU in the machine (which
lacks NMI), causing workqueue stalls that show empty backtraces because
toggle_allocation_gate() is sleeping in wait_event_idle().
Remove the task_is_running() filter so every in-flight worker in the
pool's busy_hash is dumped. The busy_hash is protected by pool->lock,
which is already held.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'Documentation/console/git@git.tavy.me:linux.git')
0 files changed, 0 insertions, 0 deletions
