io_uring: set -EINTR directly when a signal wakes up in io_cqring_wait (e9ffa5c2) · Commits · 戴 / test

We didn't use -ERESTARTSYS to tell the application layer to restart the system call, but instead return -EINTR. we can set -EINTR directly when wakeup by the signal, which can help us save an assignment operation and comparison operation. Reviewed-by:

Bob Liu <bob.liu@oracle.com> Signed-off-by:

Jackie Liu <liuyun01@kylinos.cn> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -2976,7 +2976,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
		.to_wait = min_events,
		};
		struct io_rings *rings = ctx->rings;
		int ret;
		int ret = 0;

		if (io_cqring_events(rings) >= min_events)
		return 0;
		@@ -2994,7 +2994,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
		return ret;
		}

		ret = 0;
		iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
		trace_io_uring_cqring_wait(ctx, min_events);
		do {
		@@ -3004,15 +3003,13 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
		break;
		schedule();
		if (signal_pending(current)) {
		ret = -ERESTARTSYS;
		ret = -EINTR;
		break;
		}
		} while (1);
		finish_wait(&ctx->wait, &iowq.wq);

		restore_saved_sigmask_unless(ret == -ERESTARTSYS);
		if (ret == -ERESTARTSYS)
		ret = -EINTR;
		restore_saved_sigmask_unless(ret == -EINTR);

		return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
		}

Admin message