From: Pavel Begunkov Date: Sun, 5 Dec 2021 14:37:59 +0000 (+0000) Subject: io_uring: tweak iopoll CQE_SKIP event counting X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=83a13a4181b0e874d1f196e11b953c3c9f009f68;p=linux.git io_uring: tweak iopoll CQE_SKIP event counting When iopolling the userspace specifies the minimum number of "events" it expects. Previously, we had one CQE per request, so the definition of an "event" was unequivocal, but that's not more the case anymore with REQ_F_CQE_SKIP. Currently it counts the number of completed requests, replace it with the number of posted CQEs. This allows users of the "one CQE per link" scheme to wait for all N links in a single syscall, which is not possible without the patch and requires extra context switches. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/d5a965c4d2249827392037bbd0186f87fea49c55.1638714983.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index 64add8260abba..ea7a0daa0b3bd 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2538,10 +2538,10 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) /* order with io_complete_rw_iopoll(), e.g. ->result updates */ if (!smp_load_acquire(&req->iopoll_completed)) break; + if (unlikely(req->flags & REQ_F_CQE_SKIP)) + continue; - if (!(req->flags & REQ_F_CQE_SKIP)) - __io_fill_cqe(ctx, req->user_data, req->result, - io_put_kbuf(req)); + __io_fill_cqe(ctx, req->user_data, req->result, io_put_kbuf(req)); nr_events++; }