From 87a115fb715bf1f6765e122babbcba566ada286e Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 24 Sep 2021 21:59:42 +0100 Subject: [PATCH] io_uring: force_nonspin We don't really need to pass the number of requests to complete into io_do_iopoll(), a flag whether to enforce non-spin mode is enough. Should be straightforward, maybe except io_iopoll_check(). We pass !min there, because we do never enter with the number of already reaped requests is larger than the specified @min, apart from the first iteration, where nr_events is 0 and so the final check should be identical. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/782b39d1d8ec584eae15bca0a1feb6f0571fe5b8.1632516769.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index bda302b..d605954 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2453,7 +2453,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, } static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, - long min) + bool force_nonspin) { struct io_kiocb *req, *tmp; unsigned int poll_flags = BLK_POLL_NOSLEEP; @@ -2462,9 +2462,9 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, /* * Only spin for completions if we don't have multiple devices hanging - * off our complete list, and we're under the requested amount. + * off our complete list. */ - if (ctx->poll_multi_queue || *nr_events >= min) + if (ctx->poll_multi_queue || force_nonspin) poll_flags |= BLK_POLL_ONESHOT; list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { @@ -2516,7 +2516,7 @@ static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) while (!list_empty(&ctx->iopoll_list)) { unsigned int nr_events = 0; - io_do_iopoll(ctx, &nr_events, 0); + io_do_iopoll(ctx, &nr_events, true); /* let it sleep and repeat later if can't complete a request */ if (nr_events == 0) @@ -2578,7 +2578,7 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) list_empty(&ctx->iopoll_list)) break; } - ret = io_do_iopoll(ctx, &nr_events, min); + ret = io_do_iopoll(ctx, &nr_events, !min); } while (!ret && nr_events < min && !need_resched()); out: mutex_unlock(&ctx->uring_lock); @@ -7347,7 +7347,7 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) mutex_lock(&ctx->uring_lock); if (!list_empty(&ctx->iopoll_list)) - io_do_iopoll(ctx, &nr_events, 0); + io_do_iopoll(ctx, &nr_events, true); /* * Don't submit if refs are dying, good for io_uring_register(), -- 2.7.4