Hi, On 31 October 2016 at 02:47, Sagi Grimberg <s...@grimberg.me> wrote:
> How is this simpler? It is simpler in the sense that it is a light weight primitive and that only one thread waits on the event here. In our case since 'umr_context.done' is an "on stack" variable, and has only one thread waiting on that event, no race conditions occur. So, we do not need completions here which are usually used to provide a race-free but easy-to-use solution involving multiple threads waiting on an event. >> enum ib_wc_status { >> + IB_WC_STATUS_NONE = -1, >> IB_WC_SUCCESS, >> IB_WC_LOC_LEN_ERR, >> IB_WC_LOC_QP_OP_ERR, >> > > Huh? Where did this bogus status came from? IMHO, this is polluting > the verbs interface for no good reason at all, sorry. context->status is initialized to -1 in the following code, so I just thought of replacing it with a name. static inline void mlx5_ib_init_umr_context(struct mlx5_ib_umr_context *context) { context->cqe.done = mlx5_ib_umr_done; - context->status = -1; - init_completion(&context->done); + context->status = IB_WC_STATUS_NONE; + init_waitqueue_head(&context->wq); } Thanks, Binoy