From 52dd86406dfa322c8d42b3a4328858abdc6f1d85 Mon Sep 17 00:00:00 2001 From: Dylan Yudaken Date: Fri, 25 Mar 2022 02:37:55 -0700 Subject: io_uring: enable EPOLLEXCLUSIVE for accept poll When polling sockets for accept, use EPOLLEXCLUSIVE. This is helpful when multiple accept SQEs are submitted. For O_NONBLOCK sockets multiple queued SQEs would previously have all completed at once, but most with -EAGAIN as the result. Now only one wakes up and completes. For sockets without O_NONBLOCK there is no user facing change, but internally the extra requests would previously be queued onto a worker thread as they would wake up with no connection waiting, and be punted. Now they do not wake up unnecessarily. Co-developed-by: Jens Axboe Signed-off-by: Dylan Yudaken Link: https://lore.kernel.org/r/20220325093755.4123343-1-dylany@fb.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/io_uring.c b/fs/io_uring.c index bb40c80fd9ca..e72f58e2d06d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -967,6 +967,7 @@ struct io_op_def { /* set if opcode supports polled "wait" */ unsigned pollin : 1; unsigned pollout : 1; + unsigned poll_exclusive : 1; /* op supports buffer selection */ unsigned buffer_select : 1; /* do prep async if is going to be punted */ @@ -1061,6 +1062,7 @@ static const struct io_op_def io_op_defs[] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, + .poll_exclusive = 1, }, [IORING_OP_ASYNC_CANCEL] = { .audit_skip = 1, @@ -6280,7 +6282,8 @@ static int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags) } else { mask |= POLLOUT | POLLWRNORM; } - + if (def->poll_exclusive) + mask |= EPOLLEXCLUSIVE; if (!(issue_flags & IO_URING_F_UNLOCKED) && !list_empty(&ctx->apoll_cache)) { apoll = list_first_entry(&ctx->apoll_cache, struct async_poll, -- cgit v1.2.3