Messages in this thread | | | Date | Tue, 28 Jan 2014 21:54:06 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH v2 4/5] mutex: Disable preemtion between modifying lock->owner and locking/unlocking mutex |
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On Tue, Jan 28, 2014 at 11:13:15AM -0800, Jason Low wrote: > This RFC patch disables preemption between modifying lock->owner and > locking/unlocking the mutex lock. This prevents situations where the owner > can preempt between those 2 operations, which causes optimistic spinners to > be unable to check if lock->owner is not on CPU. As mentioned in the > thread for this v1 patchset, disabling preemption is a cheap operation.
In that same thread it was also said that this wasn't really an issue at all. So what is the justification?
The patch is rather hideous.
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