Messages in this thread | | | Subject | Re: [PATCH] epoll: prevent missed events on EPOLL_CTL_MOD | From | Eric Dumazet <> | Date | Wed, 02 Jan 2013 14:08:31 -0800 |
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On Wed, 2013-01-02 at 19:32 +0000, Eric Wong wrote:
> That modification in ep_send_events_proc() is protected by ep->mtx > (as is ep_modify()), though. Maybe there are other places, but I > don't see it.
Yes, and using a mutex for protecting this field while its read from interrupt context (so without mutex synch help) is why there were races.
Some users rely on barriers included in spin_lock/spin_unlock, others in explicit barriers, or before your patch pure luck.
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