On 12/7/22 15:51, Jens Axboe wrote:
On 12/7/22 8:31 AM, Jens Axboe wrote:
On 12/6/22 8:53?PM, Pavel Begunkov wrote:
@@ -43,6 +61,15 @@ static int io_msg_ring_data(struct io_kiocb *req)
if (msg->src_fd || msg->dst_fd || msg->flags)
return -EINVAL;
+ if (target_ctx->task_complete && current != target_ctx->submitter_task) {
+ init_task_work(&msg->tw, io_msg_tw_complete);
+ if (task_work_add(target_ctx->submitter_task, &msg->tw,
+ TWA_SIGNAL))
+ return -EOWNERDEAD;
+
+ return IOU_ISSUE_SKIP_COMPLETE;
+ }
+
We should probably be able to get by with TWA_SIGNAL_NO_IPI here, no?
Considering we didn't even wake before, I'd say that's a solid yes.
I'm not so sure. It'll work, but a naive approach would also lack
IORING_SETUP_TASKRUN_FLAG and so mess with latencies when it's not
desirable.
option 1)
method = TWA_SIGNAL;
if (flags & IORING_SETUP_TASKRUN_FLAG)
method = NO_IPI;
option 2)
task_work_add(NO_IPI);
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
Might be better to have one of those.
--
Pavel Begunkov
