From patchwork Thu Jan 25 22:56:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Damato X-Patchwork-Id: 13531819 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-il1-f177.google.com (mail-il1-f177.google.com [209.85.166.177]) (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 83706134AA for ; Thu, 25 Jan 2024 22:57:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706223470; cv=none; b=HuGMuoYP8zLmhYFYzZ3vpDsXCdWi+VMesT70l2n2yopl1xTIc9y3B9QrCGkSrhjzNuayHXfExqVI2pe6Jj799glC/nA7wvXEy/bxMqboLqMBvdV2vuUodFgPJ8KTNtWN4vAdUY7Lj1DZSEC/swPYFTJbYwPHSKWSdpMVBhRYfUQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706223470; c=relaxed/simple; bh=3yteI2ybUubAH5CujHpgcS7qoJxKc8vJCs7EzjX9vMQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Sx4+LNpLYjy3KQOaTTAHSjrbxTSM0LqC4rv2VPb4KKyWVTtz8L3XyUJgjtHqtYIuaQVKP17iFRZpDVyHfOwSqDBWASr/AbpvWB3HUEP+VaR5vti9Zp+c75lrNlGjlKVTUKkqWEdjIPdvDcpnxAjkpD/rTR2g8zLnNexbrK+FUEA= 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=gK/gao8L; arc=none smtp.client-ip=209.85.166.177 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="gK/gao8L" Received: by mail-il1-f177.google.com with SMTP id e9e14a558f8ab-362a24b13e6so4780745ab.2 for ; Thu, 25 Jan 2024 14:57:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1706223468; x=1706828268; 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=o95DHArKhHsVxZUrtiTfK3GJrg5R+5zGPrNbLEZjDzs=; b=gK/gao8LZPQ14f+0l1Z/+ivgHpju3xt99PQTI/cOjX4zckT76Ao7/ofkfMZOM/dKY3 huhuUoAasEEsNHDBwxKIkVMhT1VBnxGfnbjiPJKJbswZYdFIkXci5IsVQOmx9poTHHD1 hWZFcA8fGZDbx+laWc3yhOV75Uj8m/jdqrEIM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706223468; x=1706828268; 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=o95DHArKhHsVxZUrtiTfK3GJrg5R+5zGPrNbLEZjDzs=; b=rOkpbLOpErmZxqGeTT1G/Y0FDfJFA9cNyYe44X4vTHfOkPOv5cXfH3nrty9sY0Svfq QsmzeCbUR0gxUHw1zVDiByF+G9GB3ZMnnCAmzW0odBjSvH0cXUWtLNFvM/Lmzg5lU+G1 WB9frjcLlj2yLN6EXAa+wG2EJbObpmTUeassItRlwLwcRgG3RblfQpKEnMSl3sAguQuO 8ke4VPighdRDiuid3e/tNtVGZtIAsnVi53ZHe5k6YhlwNUxah03Rbp7N/dcBWK6hvsx0 a1VHYvrSjZ//Tvp6aNW1etupdM9wnZsYKBEUSurA10F8VW8vAQEartniQQjUB01EB6tD KM2g== X-Gm-Message-State: AOJu0Yx7IT67/QjO+Hqz3W92HcpZiQqOaRjr5jyYHgvyCmmyteUo4ozk uHLgr/P50NS+RDPhiofXC3cC60NrKdqKFuQn0aO/op509JiWpVfFVhv7S5fWTVwdY/ef9jz9uZQ 508M= X-Google-Smtp-Source: AGHT+IGAK1VuD1OD6e8Ft02aMvZ4LCBGzC3c9/ElbXUFGVr5EYlwpCty3o6SVFhtKkGYwoGiIA7Yrw== X-Received: by 2002:a05:6e02:12ea:b0:360:76fb:a894 with SMTP id l10-20020a056e0212ea00b0036076fba894mr557277iln.62.1706223467756; Thu, 25 Jan 2024 14:57:47 -0800 (PST) Received: from localhost.localdomain ([2620:11a:c018:0:ea8:be91:8d1:f59b]) by smtp.gmail.com with ESMTPSA id z24-20020a631918000000b005d68962e1a7sm19948pgl.24.2024.01.25.14.57.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jan 2024 14:57:47 -0800 (PST) From: Joe Damato To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: chuck.lever@oracle.com, jlayton@kernel.org, linux-api@vger.kernel.org, brauner@kernel.org, edumazet@google.com, davem@davemloft.net, alexander.duyck@gmail.com, sridhar.samudrala@intel.com, kuba@kernel.org, willemdebruijn.kernel@gmail.com, weiwan@google.com, Joe Damato , Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)) Subject: [PATCH net-next v3 2/3] eventpoll: Add per-epoll busy poll packet budget Date: Thu, 25 Jan 2024 22:56:58 +0000 Message-Id: <20240125225704.12781-3-jdamato@fastly.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240125225704.12781-1-jdamato@fastly.com> References: <20240125225704.12781-1-jdamato@fastly.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org When using epoll-based busy poll, the packet budget is hardcoded to BUSY_POLL_BUDGET (8). Users may desire larger busy poll budgets, which can potentially increase throughput when busy polling under high network load. Other busy poll methods allow setting the busy poll budget via SO_BUSY_POLL_BUDGET, but epoll-based busy polling uses a hardcoded value. Fix this edge case by adding support for a per-epoll context busy poll packet budget. If not specified, the default value (BUSY_POLL_BUDGET) is used. Signed-off-by: Joe Damato --- fs/eventpoll.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 4503fec01278..40bd97477b91 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -229,6 +229,8 @@ struct eventpoll { unsigned int napi_id; /* busy poll timeout */ u64 busy_poll_usecs; + /* busy poll packet budget */ + u16 busy_poll_budget; #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -437,10 +439,14 @@ static bool ep_busy_loop_end(void *p, unsigned long start_time) static bool ep_busy_loop(struct eventpoll *ep, int nonblock) { unsigned int napi_id = READ_ONCE(ep->napi_id); + u16 budget = READ_ONCE(ep->busy_poll_budget); + + if (!budget) + budget = BUSY_POLL_BUDGET; if ((napi_id >= MIN_NAPI_ID) && ep_busy_loop_on(ep)) { napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false, - BUSY_POLL_BUDGET); + budget); if (ep_events_available(ep)) return true; /* @@ -2098,6 +2104,7 @@ static int do_epoll_create(int flags) } #ifdef CONFIG_NET_RX_BUSY_POLL ep->busy_poll_usecs = 0; + ep->busy_poll_budget = 0; #endif ep->file = file; fd_install(fd, file);