Messages in this thread | | | Date | Thu, 21 Jul 2016 12:23:56 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH v4] ipc/msg: Implement lockless pipelined wakeups |
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* Davidlohr Bueso | 2016-07-20 17:16:12 [-0700]:
>Just as with expunge_all and the E2BIG case, could you remove that explicit >barrier (B) and just rely on wake_q_add?
Just did. So we have just a smp_rmb() on the reader side and the comment talks about smb_wmb() and at the spot where we should have the smb_wmb we have a comment why we don't have one :) For my understanding: we need that smp_rmb() to ensure that everything past that cmpxchg() is visible on all other CPUs so we don't have the wakeup before we r_msg reads != -EAGAIN, right?
>Thanks, >Davidlohr
Sebastian
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