From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cloud48395.mywhc.ca (cloud48395.mywhc.ca [173.209.37.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EAC1192B8A for ; Mon, 12 Aug 2024 22:38:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.209.37.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723502339; cv=none; b=ezWfBidR7gHOrrA4WlnPaSk5c/JivCDAuZfsBnifC0Zg8LaKtmr9cKQrraiQxptCoEe0ZC8tTbLl6pG4KGFc9ZenFhuuuVxCEpuV+TWOy1d7JUG1+ORD6VQfRi+nPXecBOd+RQf2i+CoTk8D4x2oZ6Rl9G6DD3OnxecWQ2z3e5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723502339; c=relaxed/simple; bh=ALCSyRtqC6uRSLbvognVyjKmLOPtBQ9hOTRhX83w4Eg=; h=From:Message-ID:To:Date:Subject; b=nP0H3xr0ChCiuaCa1fD00vrx1aNHyOAtSCye+SbtDj4/uSOW55ASBKKU3iNghBVikVqO5zfWbjUAiexb+pcC9hNzUoSpP5ie4QdVyU+Uo/E6Jd+Ad08q4IVoaJ0K7icH07U9cm+PoYwVKXNyeDGA91Djao1tUDxySTjR1xVYgo8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=trillion01.com; spf=pass smtp.mailfrom=trillion01.com; arc=none smtp.client-ip=173.209.37.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=trillion01.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=trillion01.com Received: from [45.44.224.220] (port=55702 helo=localhost) by cloud48395.mywhc.ca with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1sddgl-00022X-2S; Mon, 12 Aug 2024 18:38:55 -0400 From: Olivier Langlois Message-ID: <19905713556ad4195d1bf8c8c1e38fc2683b592b.1723502167.git.olivier@trillion01.com> To: Jens Axboe ,Pavel Begunkov ,io-uring@vger.kernel.org Date: Tue, 30 Jul 2024 17:10:21 -0400 Subject: [PATCH v3] io_uring: do the sqpoll napi busy poll outside the submission block X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cloud48395.mywhc.ca X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - trillion01.com X-Get-Message-Sender-Via: cloud48395.mywhc.ca: authenticated_id: olivier@trillion01.com X-Authenticated-Sender: cloud48395.mywhc.ca: olivier@trillion01.com X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: there are many small reasons justifying this change. 1. busy poll must be performed even on rings that have no iopoll and no new sqe. It is quite possible that a ring configured for inbound traffic with multishot be several hours without receiving new request submissions 2. NAPI busy poll does not perform any credential validation 3. If the thread is awaken by task work, processing the task work is prioritary over NAPI busy loop. This is why a second loop has been created after the io_sq_tw() call instead of doing the busy loop in __io_sq_thread() outside its credential acquisition block. Signed-off-by: Olivier Langlois --- io_uring/sqpoll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c index cc4a25136030..b74db3988b7f 100644 --- a/io_uring/sqpoll.c +++ b/io_uring/sqpoll.c @@ -195,9 +195,6 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) ret = io_submit_sqes(ctx, to_submit); mutex_unlock(&ctx->uring_lock); - if (io_napi(ctx)) - ret += io_napi_sqpoll_busy_poll(ctx); - if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait)) wake_up(&ctx->sqo_sq_wait); if (creds) @@ -322,6 +319,10 @@ static int io_sq_thread(void *data) if (io_sq_tw(&retry_list, IORING_TW_CAP_ENTRIES_VALUE)) sqt_spin = true; + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + if (io_napi(ctx)) + io_napi_sqpoll_busy_poll(ctx); + if (sqt_spin || !time_after(jiffies, timeout)) { if (sqt_spin) { io_sq_update_worktime(sqd, &start); -- 2.46.0