From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9579918DF7D for ; Tue, 30 Jul 2024 20:29:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722371368; cv=none; b=RVtCVnvYCUIz/YilUNgb6FK2isHvB6NOaY991+S8SovigXfP9zzEKicLpsy03oXiDCvx4ujUn3f8k5YGP+XwAuPm5ixC1X2POTNLHsnING9Ptn/BQ4kXrF2RDVPJH3s2y6IeNIHhY660y2lLEJR+gDWakzvCiw3bwlIrBzPBLrw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722371368; c=relaxed/simple; bh=zovKaqxO0iZW2msDKkeqZYOYPS1G0opJSaZ5TvPDHgo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ixq+Ew0jGOShHABHJ6KZAV1gZVN4VRq89selXC9UH+TDXlhAOquUwQYzgfenTs6VbPItkhhtgAqLVmxY2A/Cp/CGw0kXZxSSQaI3ZKSHxyZTiWRVWdBxLOYBssKpY7AJxOZz7FW8jeGk1GmzQ1E5QKR2KAMKQ+jq/is4aiE29wA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bwO2s8VF; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bwO2s8VF" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-427b1d4da32so1410845e9.0 for ; Tue, 30 Jul 2024 13:29:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1722371364; x=1722976164; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=WsQgCMWM9FHgRe4Z+rQk9mNDKnWifQacOoNk8pNYn8U=; b=bwO2s8VFbBAGGjWJ1w1Cg80v/HFVzzEwp+aWEzHPoQaMnQvfKjONSV1twT5jSu3yIJ ulMTDH67/XkZE+0kzmhrj274yj0fYZRZv4bf0IIC+BMn7flLdTiYIGkXj4hv8uFD9vqz DzNUjYKYXyxO2qip1kVNrgSaXMtbuPb82GhIUQAFVtawVaxIWSMFrI+fXHLSvT72LL8Y 70hKEws9iiH5TzVqe6Bg3y3D+rtKtsz67mO75HqsKzRNdVRJFLyRc+LitdsErnETz2R4 2dClx+42WBN7jD+FBH0e72zmkXv8lhBIZLLVqqrVwMV7sfodWFt3C9m+L+yXgXfRuCsp RZOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722371364; x=1722976164; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WsQgCMWM9FHgRe4Z+rQk9mNDKnWifQacOoNk8pNYn8U=; b=hNhs1jLTM/he6BaWEJlliIcr4x5dqTwH9q3JkGc3kGRp7mnEWAepaImuhntQZavjqb GrzPaVGMutie45x4GvrqpdInfAIijgFroD5VN75zHVJxeYFMgI4SaCfWdsfHJ8l2x9Rw L8X+ZdPP6dbkjJgwQInenX3/kcnyIe5djtinevITyrCO9BRPM77+D9uPi4zo2qJMhydb e4rIzsNZkqgalAxzjDlMlugk2Qb5J/KyLmz8LLmExn+e4sQ4yfOvCM1wrJrNl5tFW9Hp WEJyAF1vfyz3z5ddB8xEpJPuXxZ0Oqr2A80lxSjfSm2dSssobhhLk62I9PMbpvYX+KWV Ej5A== X-Gm-Message-State: AOJu0Yy9v0gapgxbHsQoZLAUZChkT/MiP49mU3/4r3wQx955p/Ioehl4 UySYjSpHks16lg9ntkvn4HSemAhdKxS/By+HcY4GPa08YYu3QQSlgfs+7A== X-Google-Smtp-Source: AGHT+IF2PcvlXs4+keKHEMyx0npqCgE8zPdZ3xZdTFhoDxRvctH4z2Yso3CvCX6JwA28OWMnxBb2Lw== X-Received: by 2002:a05:600c:a41:b0:428:9c0:2ad with SMTP id 5b1f17b1804b1-4282445d0c0mr19886095e9.18.1722371364248; Tue, 30 Jul 2024 13:29:24 -0700 (PDT) Received: from 127.0.0.1localhost ([85.255.235.94]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42808457c7fsm214488065e9.32.2024.07.30.13.29.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jul 2024 13:29:23 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, Lewis Baker Subject: [PATCH 2/3] io_uring/napi: delay napi timeout adjustment Date: Tue, 30 Jul 2024 21:29:43 +0100 Message-ID: <2766891d83b5d1ff231210ee3d09387398ef29cc.1722357468.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Instead adjusting busy polling time in io_cqring_wait(), rely on the deadline value and delay the check until io_napi_busy_loop_timeout() is called inside the napi busy polling loop. There is a side effect of comparing a cpu local clock with ktime_get(), however waiting timeouts are usually long enough not to care and napi.c is already careless about mixing time flavours, i.e. io_napi_blocking_busy_loop() gets a cpu local time before disabling preemption. Signed-off-by: Pavel Begunkov --- io_uring/io_uring.c | 1 - io_uring/napi.c | 30 ++++++------------------------ io_uring/napi.h | 16 ---------------- 3 files changed, 6 insertions(+), 41 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 3942db160f18..9ec07f76ad19 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2423,7 +2423,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, dt = timespec64_to_ktime(ts); iowq.timeout = ktime_add(dt, ktime_get()); - io_napi_adjust_timeout(ctx, &iowq, dt); } if (sig) { diff --git a/io_uring/napi.c b/io_uring/napi.c index a670f49e30ef..c5c1177e2fb4 100644 --- a/io_uring/napi.c +++ b/io_uring/napi.c @@ -109,12 +109,15 @@ static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale) } static inline bool io_napi_busy_loop_timeout(ktime_t start_time, - ktime_t bp) + struct io_wait_queue *iowq) { + ktime_t bp = iowq->napi_busy_poll_dt; + if (bp) { ktime_t end_time = ktime_add(start_time, bp); ktime_t now = net_to_ktime(busy_loop_current_time()); + end_time = min(end_time, iowq->timeout); return ktime_after(now, end_time); } @@ -130,8 +133,7 @@ static bool io_napi_busy_loop_should_end(void *data, return true; if (io_should_wake(iowq) || io_has_work(iowq->ctx)) return true; - if (io_napi_busy_loop_timeout(net_to_ktime(start_time), - iowq->napi_busy_poll_dt)) + if (io_napi_busy_loop_timeout(net_to_ktime(start_time), iowq)) return true; return false; @@ -271,27 +273,6 @@ int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg) return 0; } -/* - * __io_napi_adjust_timeout() - adjust busy loop timeout - * @ctx: pointer to io-uring context structure - * @iowq: pointer to io wait queue - * @ts: pointer to timespec or NULL - * - * Adjust the busy loop timeout according to timespec and busy poll timeout. - * If the specified NAPI timeout is bigger than the wait timeout, then adjust - * the NAPI timeout accordingly. - */ -void __io_napi_adjust_timeout(struct io_ring_ctx *ctx, struct io_wait_queue *iowq, - ktime_t to_wait) -{ - ktime_t poll_dt = READ_ONCE(ctx->napi_busy_poll_dt); - - if (to_wait) - poll_dt = min(poll_dt, to_wait); - - iowq->napi_busy_poll_dt = poll_dt; -} - /* * __io_napi_busy_loop() - execute busy poll loop * @ctx: pointer to io-uring context structure @@ -304,6 +285,7 @@ void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) if ((ctx->flags & IORING_SETUP_SQPOLL) || !ctx->napi_enabled) return; + iowq->napi_busy_poll_dt = READ_ONCE(ctx->napi_busy_poll_dt); iowq->napi_prefer_busy_poll = READ_ONCE(ctx->napi_prefer_busy_poll); io_napi_blocking_busy_loop(ctx, iowq); } diff --git a/io_uring/napi.h b/io_uring/napi.h index 88f1c21d5548..87e30b4f8d9e 100644 --- a/io_uring/napi.h +++ b/io_uring/napi.h @@ -17,8 +17,6 @@ int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg); void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock); -void __io_napi_adjust_timeout(struct io_ring_ctx *ctx, - struct io_wait_queue *iowq, ktime_t to_wait); void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq); int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx); @@ -27,15 +25,6 @@ static inline bool io_napi(struct io_ring_ctx *ctx) return !list_empty(&ctx->napi_list); } -static inline void io_napi_adjust_timeout(struct io_ring_ctx *ctx, - struct io_wait_queue *iowq, - ktime_t to_wait) -{ - if (!io_napi(ctx)) - return; - __io_napi_adjust_timeout(ctx, iowq, to_wait); -} - static inline void io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) { @@ -86,11 +75,6 @@ static inline bool io_napi(struct io_ring_ctx *ctx) static inline void io_napi_add(struct io_kiocb *req) { } -static inline void io_napi_adjust_timeout(struct io_ring_ctx *ctx, - struct io_wait_queue *iowq, - ktime_t to_wait) -{ -} static inline void io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) { -- 2.45.2