From patchwork Fri Nov 1 00:48:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Damato X-Patchwork-Id: 13858538 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) (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 6E22C5588E for ; Fri, 1 Nov 2024 00:49:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730422168; cv=none; b=UDzrA+efHowJh8Vofbyj0qAI5QeZ9cTrQGzewjw46L1uC7YBdKnsAtVCz/qHBl72TgzNUMb3fYkfDwcEJA7PMle6u8cFn7r2CjNqayy7js6LnnxugfmwuQxy5zafyE3N4IM59GeIVIz9DHhfXqrT84eijwBSEY91Z9sCnonkxGo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730422168; c=relaxed/simple; bh=nTVHqzMjxVaFGtFwKysoiZKk4YEWDQibSQdexzn6DUQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eW0aO2NtgMv/pKrWumUTHDBpUR21c9D7qMXxywc49KKY6hXsb+SNpz2pfd9YhjIiFVNfYhR5xHf/EoNkcOxbg74KrYek0J+W9wpwYOuPa/SyosVN8soRpBCx1W495NiKDn9+Nj8W00a13i33M3/gxip3ylL+MJWb8JY6G+RWEN4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com; spf=pass smtp.mailfrom=fastly.com; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b=g4FsDE9h; arc=none smtp.client-ip=209.85.210.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fastly.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b="g4FsDE9h" Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-71e4c2e36daso1836747b3a.0 for ; Thu, 31 Oct 2024 17:49:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1730422162; x=1731026962; 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=PhVjl1Gry+K7A+Im8XGVxnCvKP7p4PT8RH2VXkmIRG8=; b=g4FsDE9hSub8oOafoJ2gM6+1cVpVJSgXSqTISVkXgSXVlUIXFLAUkorN+2I2tYb8w4 ZsAr5Ny9y75dp1e0RNzDFG9s0bKUTrmtgxuETbtBLqHq09jH6z+8QCdgiZL4qSUNoDPG OoHAeZhE5nXBgAsjOtK+lnDwVSncQedRyhq9M= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730422162; x=1731026962; 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=PhVjl1Gry+K7A+Im8XGVxnCvKP7p4PT8RH2VXkmIRG8=; b=JHXLMoKIi4GtTTtdfGxnQiW7ulqAuxg3okULtXdAMOBNN4BFRxvhOjR3/zhzQfGcPs G+7HIByJYx0sFeO7VMVDqMA02asYtS0RBz4KlaaF0AmRhfT3/kxDiD0fH1gEpd5CNEhL Ej9tVgEvuewz0y8bLnTiyHAlXC5j6nlUknnMuRUXgqU4TJ5W8rk4l8/uWUVBztfhUzmG j6VclTzy3uaAUeI7eZJo8HeUt5q8GOcBrlYhReSqg6csb0S2vYP++c+QJAx8G5IPCwoo NLsNuI+ayhNo2L2/dPaRWtl99nZawL7tWwDKxGCY6mz3tAKah2x7EhcD2HNo3Wkeq23v OeTQ== X-Forwarded-Encrypted: i=1; AJvYcCV6wIUUAwcmli8VJiDATwFLX6ypxHpgsCQ6zXsh+MYhcUxJ1+2G262q+1NyJzgIvvWBqAfcSPB836+fAvQW@vger.kernel.org X-Gm-Message-State: AOJu0YwfQCRVi7F7+PtzdL8ZUJNmJMZoo3ERbz2YlCBn6YtaO6DzksJf +wi2VjxvnK4A8basE9bt28Ztv7te+qKGz6v8sUKyYFDjk6/B6J94tefkyXx94CA= X-Google-Smtp-Source: AGHT+IEH+IJhhOqJTbEvWAGa+fGdT8tPf8aU+VscbzoV1yq0/QUbvAn4d2Gmi8WnlrR0slwEVeyS9g== X-Received: by 2002:a05:6a20:be18:b0:1db:822f:36d8 with SMTP id adf61e73a8af0-1db94f33e87mr6081599637.3.1730422161735; Thu, 31 Oct 2024 17:49:21 -0700 (PDT) Received: from localhost.localdomain ([2620:11a:c019:0:65e:3115:2f58:c5fd]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7ee45a12c27sm1585365a12.93.2024.10.31.17.49.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2024 17:49:21 -0700 (PDT) From: Joe Damato To: netdev@vger.kernel.org Cc: pabeni@redhat.com, namangulati@google.com, edumazet@google.com, amritha.nambiar@intel.com, sridhar.samudrala@intel.com, sdf@fomichev.me, peter@typeblog.net, m2shafiei@uwaterloo.ca, bjorn@rivosinc.com, hch@infradead.org, willy@infradead.org, willemdebruijn.kernel@gmail.com, skhawaja@google.com, kuba@kernel.org, Martin Karsten , Joe Damato , Alexander Viro , Christian Brauner , Jan Kara , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH net-next v3 5/7] eventpoll: Control irq suspension for prefer_busy_poll Date: Fri, 1 Nov 2024 00:48:32 +0000 Message-Id: <20241101004846.32532-6-jdamato@fastly.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20241101004846.32532-1-jdamato@fastly.com> References: <20241101004846.32532-1-jdamato@fastly.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Martin Karsten When events are reported to userland and prefer_busy_poll is set, irqs are temporarily suspended using napi_suspend_irqs. If no events are found and ep_poll would go to sleep, irq suspension is cancelled using napi_resume_irqs. Signed-off-by: Martin Karsten Co-developed-by: Joe Damato Signed-off-by: Joe Damato Tested-by: Joe Damato Tested-by: Martin Karsten Acked-by: Stanislav Fomichev --- rfc -> v1: - move irq resume code from ep_free to a helper which either resumes IRQs or does nothing if !defined(CONFIG_NET_RX_BUSY_POLL). fs/eventpoll.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index f9e0d9307dad..36a657594352 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -457,6 +457,8 @@ static bool ep_busy_loop(struct eventpoll *ep, int nonblock) * it back in when we have moved a socket with a valid NAPI * ID onto the ready list. */ + if (prefer_busy_poll) + napi_resume_irqs(napi_id); ep->napi_id = 0; return false; } @@ -540,6 +542,22 @@ static long ep_eventpoll_bp_ioctl(struct file *file, unsigned int cmd, } } +static void ep_suspend_napi_irqs(struct eventpoll *ep) +{ + unsigned int napi_id = READ_ONCE(ep->napi_id); + + if (napi_id >= MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll)) + napi_suspend_irqs(napi_id); +} + +static void ep_resume_napi_irqs(struct eventpoll *ep) +{ + unsigned int napi_id = READ_ONCE(ep->napi_id); + + if (napi_id >= MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll)) + napi_resume_irqs(napi_id); +} + #else static inline bool ep_busy_loop(struct eventpoll *ep, int nonblock) @@ -557,6 +575,14 @@ static long ep_eventpoll_bp_ioctl(struct file *file, unsigned int cmd, return -EOPNOTSUPP; } +static void ep_suspend_napi_irqs(struct eventpoll *ep) +{ +} + +static void ep_resume_napi_irqs(struct eventpoll *ep) +{ +} + #endif /* CONFIG_NET_RX_BUSY_POLL */ /* @@ -788,6 +814,7 @@ static bool ep_refcount_dec_and_test(struct eventpoll *ep) static void ep_free(struct eventpoll *ep) { + ep_resume_napi_irqs(ep); mutex_destroy(&ep->mtx); free_uid(ep->user); wakeup_source_unregister(ep->ws); @@ -2005,8 +2032,10 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events, * trying again in search of more luck. */ res = ep_send_events(ep, events, maxevents); - if (res) + if (res) { + ep_suspend_napi_irqs(ep); return res; + } } if (timed_out)