workqueue: Report work funcs that trigger automatic CPU_INTENSIVE mechanism
Workqueue now automatically marks per-cpu work items that hog CPU for too
long as CPU_INTENSIVE, which excludes them from concurrency management and
prevents stalling other concurrency-managed work items. If a work function
keeps running over the thershold, it likely needs to be switched to use an
unbound workqueue.
This patch adds a debug mechanism which tracks the work functions which
trigger the automatic CPU_INTENSIVE mechanism and report them using
pr_warn() with exponential backoff.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
2 files changed
