On Thu, Jan 11, 2018 at 04:02:33PM +0000, Bart Van Assche wrote: > On Thu, 2018-01-11 at 08:22 +0200, Leon Romanovsky wrote: > > The proposed patch definitely decreases the chance of races, but it is not fixing them. > > There is a chance to have change in qp state immediately after your "if ..." check. > > Hello Leon, > > Please have a look at rxe_qp_error() and you will see that the patch I posted > is a proper fix. In the scenario you described rxe_qp_error() will trigger a > run of rxe_completer(). Bart, What am I missing? CPU1 CPU2 if (unlikely.... <--- /* move the qp to the error state */ void rxe_qp_error(struct rxe_qp *qp) { qp->req.state = QP_STATE_ERROR; qp->resp.state = QP_STATE_ERROR; qp->attr.qp_state = IB_QPS_ERR; ---> rxe_run_task(&qp->req.task, must_sched); It is more or less the same as without "if (unlikely..." Thanks > > Bart.
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