Messages in this thread | | | Date | Tue, 17 Oct 2023 23:53:12 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH] workqueue: Provide one lock class key per work_on_cpu() callsite |
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On Sun, Sep 24, 2023 at 05:07:02PM +0200, Frederic Weisbecker wrote: > All callers of work_on_cpu() share the same lock class key for all the > functions queued. As a result the workqueue related locking scenario for > a function A may be spuriously accounted as an inversion against the > locking scenario of function B such as in the following model: > > long A(void *arg) > { > mutex_lock(&mutex); > mutex_unlock(&mutex); > } > > long B(void *arg) > { > } > > void launchA(void) > { > work_on_cpu(0, A, NULL); > } > > void launchB(void) > { > mutex_lock(&mutex); > work_on_cpu(1, B, NULL); > mutex_unlock(&mutex); > } > > launchA and launchB running concurrently have no chance to deadlock. > However the above can be reported by lockdep as a possible locking > inversion because the works containing A() and B() are treated as > belonging to the same locking class.
Sorry about the delay. I missed this one. Applied to wq/for-6.7.
Thanks.
-- tejun
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