From patchwork Wed Jan 31 18:08:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Damato X-Patchwork-Id: 13539847 Received: from mail-oo1-f42.google.com (mail-oo1-f42.google.com [209.85.161.42]) (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 7EDAB1386AB for ; Wed, 31 Jan 2024 18:09:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706724583; cv=none; b=nTLBcrDxExFoCW/7zbgdgIPOXotEp8twe9+I9yahfBpvls/SaEYbl2hLwSkjCNEA/kjjeeRh9dwW+hpDvzL65vBSpdeFhq/f+zEu/DZ0wPhyLb7TpKCzsO4wVHG6QH9IBFhcoz2PU2p/sEokL5aRlwNuODrMZgnJDwlYSIeGnh8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706724583; c=relaxed/simple; bh=+NvwukKrlDHz6eylGdtOKZKD8hFQLLmD1KnjinUcTaA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cnu+uQ/WDx+flwoPk03E2KJcuxp5Rbb5iwE6QHSoIICwdKoIRFk7TMEXnwxK1c5sk1xHwqnNPx3Elvs4bIY6603ufze96roi4fQ/tSIM90IpOWdZs11Ufm0No5GYs+58j3ZnfQCtDrzgHJk7xiAxnJ6aBWgkQiS3MTzhrLn2GaA= 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=KnHVwhWv; arc=none smtp.client-ip=209.85.161.42 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="KnHVwhWv" Received: by mail-oo1-f42.google.com with SMTP id 006d021491bc7-598699c0f1eso52056eaf.2 for ; Wed, 31 Jan 2024 10:09:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1706724580; x=1707329380; 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=dis0Zk83NVRgFQ7j5PMchP4NSpK2O2E2OiTy+PShPHQ=; b=KnHVwhWvgJevhVlcnikP7QUDjrpfFLbgEZhFUoIjHIFCR/MNbfMrJXrQ4IkSM5TrqK 2UDPfy1N3PUya8cOMl+64EFU1OoCdR0ueVBFh3poG/6pfowuA0LDBbpd2CEe4mxyO5Ik 4vT9JFBioIWaYPE9QI3DKf+tA05SI0ri3vzZQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706724580; x=1707329380; 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=dis0Zk83NVRgFQ7j5PMchP4NSpK2O2E2OiTy+PShPHQ=; b=d++sOnER+yfVaGgBnLpTQa/ZE1mEx1emVUdS1bSh+SqrNy1iv4+nFKxbZxUd8lNVDF byRTfI8fndmF+YvlbR3qYIzBIKeTzQppBEth49FCLUiS2qHuxrxpGIZbYyZP9X3FyMzy aBHlHQX0Sk3L+4j3KSHaELcueLd9BBQeJ32rbG5Pq+vQcoYtC53I+PuN6mmWb/H6X7v1 V19pFT9jK/eKu+vxpiUgBSYrCqbtZjy3QVIlsr8QzMQRAObxB6AtxwqTadhSptAXF0vz +qiSkzS6wlB9ALiML3vYt0j5HVRltOpCZ/6IwuR8ycbQ7EbnHp7EB1wI6r4hrEL612Ib AZAg== X-Gm-Message-State: AOJu0YzrsBYf6jVfB/50MfL6JWcxfhGrMeErPG9q1koTT+S6HUi/JloM MCZg4j5IKpxvIeuIId3CHAjgYAVgnbnmIUckBiM+LgnlvrOqEMnka5qJEZM37qc= X-Google-Smtp-Source: AGHT+IE3WSCEhFcdCAfWNl58ynuO3Wg26xmq2qCV3dHWjIH6sZZ7QtfQiNgztoOEGf9zo7iiBN0/rw== X-Received: by 2002:a05:6358:4b4b:b0:176:915a:c7b7 with SMTP id ks11-20020a0563584b4b00b00176915ac7b7mr32979rwc.31.1706724580488; Wed, 31 Jan 2024 10:09:40 -0800 (PST) Received: from localhost.localdomain ([2620:11a:c018:0:ea8:be91:8d1:f59b]) by smtp.gmail.com with ESMTPSA id v24-20020a634818000000b005cfbf96c733sm10876004pga.30.2024.01.31.10.09.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Jan 2024 10:09:40 -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, David.Laight@ACULAB.COM, arnd@arndb.de, Joe Damato , Alexander Viro , Jan Kara , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)) Subject: [PATCH net-next v5 2/3] eventpoll: Add per-epoll busy poll packet budget Date: Wed, 31 Jan 2024 18:08:04 +0000 Message-Id: <20240131180811.23566-3-jdamato@fastly.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240131180811.23566-1-jdamato@fastly.com> References: <20240131180811.23566-1-jdamato@fastly.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 ce75189d46df..3985434df527 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);