From patchwork Wed Jan 31 18:08:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Damato X-Patchwork-Id: 194892 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7301:2087:b0:106:209c:c626 with SMTP id gs7csp2069664dyb; Wed, 31 Jan 2024 10:11:02 -0800 (PST) X-Google-Smtp-Source: AGHT+IGAdNNaAg7AB7uXcpB5U9ebPPNzWcEy+xafbsTgsDprXs8GMLsdB0idiWwaDxbVkWXVt07q X-Received: by 2002:a05:6402:430a:b0:55f:a33a:6ad2 with SMTP id m10-20020a056402430a00b0055fa33a6ad2mr660631edc.24.1706724662401; Wed, 31 Jan 2024 10:11:02 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1706724662; cv=pass; d=google.com; s=arc-20160816; b=L9FAwaW9XvrBTjWhmOuMAtf3Ouce0piGNiMcfFa1usPhfn0KYPMczD1x5695KXNqSC 702ispbdLJauKSb3loFIqGdnYevd+bojGtgHd050qKnCBwMJMeuTOIIuIx2+5sWjJOnd MojRSQYZNETB7uGXsa3JM2p6Zargiw5azu4pTP0fJxadSs/t7uTgEf5i8MvY1S/2i+Dm RoMVnbfwdnomDHgIQ0H0oLCxwh3WE5haOf73nCxRX/OL+/6T4ezZP5K6MxBmgbukd5RJ nneEncQZ6q2ONoN2eY44DhkAbfgKbEpGrVV52PdUPgNWH0pT7OuWShRp+OHnkqfetaQK zDDg== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=XPyBFpA03VgPUcSSFnhqRnjQDUKtK8Zok+qzBXzC1y0=; fh=lanZMMQSJbBWwXfb+Qr5p9tCBtUegS2BzYZa2TAAp3s=; b=dTCXucTYoYATk9jS0EkKXyvTJalI/6skDg7BKbFzniT/ANu0pihK6gXnMqquhICAYF 40FbX9lnufcVieSp+B0OySGe9UnF1/KZ8J5DLr6KLejG2TrHoojxyYZsSXkIhnIy8C12 /5ix/uW1GBYKzO2mNAO1Goh5x30NNUkWkyz0SyytGIJ+zG+MvdtKt3EWTbbkZ5mQioWc m0zTLxbHsevfIWZYJc7D5JOfMdz2KjT13i8AV3SgToUQSDNQkjjtLWIT0xw8FO0zd8nE qxmTRrvuRT560vve1N40ASu7sSDa7R8E+29ghryfqN9w7lKR791jWQCTBNDSt0gu9v7u 5ELw==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@fastly.com header.s=google header.b="QN/mleoj"; arc=pass (i=1 spf=pass spfdomain=fastly.com dkim=pass dkdomain=fastly.com dmarc=pass fromdomain=fastly.com); spf=pass (google.com: domain of linux-kernel+bounces-46954-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) smtp.mailfrom="linux-kernel+bounces-46954-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=fastly.com X-Forwarded-Encrypted: i=1; AJvYcCUyXOajOkH1pwalZmotGfc1j/IMOv0VM+UxudfD88OK7kW5DUuUK0DFY8UGNuJqol22hunyKyLl4HUuK5fMFefdW0UYMw== Received: from am.mirrors.kernel.org (am.mirrors.kernel.org. [147.75.80.249]) by mx.google.com with ESMTPS id 13-20020a0564021f4d00b0055c8e01428dsi5947007edz.123.2024.01.31.10.11.02 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Jan 2024 10:11:02 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-46954-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249; Authentication-Results: mx.google.com; dkim=pass header.i=@fastly.com header.s=google header.b="QN/mleoj"; arc=pass (i=1 spf=pass spfdomain=fastly.com dkim=pass dkdomain=fastly.com dmarc=pass fromdomain=fastly.com); spf=pass (google.com: domain of linux-kernel+bounces-46954-ouuuleilei=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) smtp.mailfrom="linux-kernel+bounces-46954-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=fastly.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id D0B441F26068 for ; Wed, 31 Jan 2024 18:11:01 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3B6F613BE94; Wed, 31 Jan 2024 18:09:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b="QN/mleoj" Received: from mail-io1-f48.google.com (mail-io1-f48.google.com [209.85.166.48]) (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 46571130E35 for ; Wed, 31 Jan 2024 18:09:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.48 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706724582; cv=none; b=c1tNh7BDF1deeNkwYQyo09y0LI4fTTxMHaB6g+ATyvRuRoiIIXgJmVOfKS4FwP4GMsRZCAJ2akcDL9TUGSpy5cIi0NFB3HzIR9ZuyUvYRisIRHJnKqNEWikJhqoODHA481ioVNeXAIvlkzeq6nNYaQIixxZ1dln8d/LuubqO1Ko= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706724582; c=relaxed/simple; bh=iOH3rDvMU6l8EibI+PkwMyfqV5hY0EoK3y01y1v3/4g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=iKR4xbjhK2x0jEVr8PyuehbiWu9bHXkZ84IGwgsY7usiIOQMmASyWCiCTiyb/gCpM4zgbF6C7ZawWEEcfsntUTNiR3T4bqbZqmQ3HgzzxweMN+aHu49N/c6WTfywPDcRgfOO2EDjiS5R/V82Th8Vtu/zHdZOiH50X0zV7JBPAbE= 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=QN/mleoj; arc=none smtp.client-ip=209.85.166.48 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 Received: by mail-io1-f48.google.com with SMTP id ca18e2360f4ac-7c009016d5bso1946039f.1 for ; Wed, 31 Jan 2024 10:09:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1706724578; x=1707329378; 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=XPyBFpA03VgPUcSSFnhqRnjQDUKtK8Zok+qzBXzC1y0=; b=QN/mleojEw9HkQpWKu/XT/shVQnhEDCSJnfeqqIU1XjaWrNL1oKAVNbbR1q4FVA8Rp 9SGHlk517ohEulqpzVOU7svJFvmmTmjqvvc0Uf/UThQfSjVkZWhax/Vdx25yyBrf5T6Z ZG87YKxa0QRTrX3AMqbkiWkfms8jWWpSJzNms= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706724578; x=1707329378; 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=XPyBFpA03VgPUcSSFnhqRnjQDUKtK8Zok+qzBXzC1y0=; b=Gt865RnLr7sbgj2XD700iDU9JWb2N/RPu76RZiAKVSJ0ib8tuoINiDPgl3gFqjlq7u pSqWVf+sSmho+q9jZLFj7hwM40Rjj9OauZrqyKq7dhEsf6QG/eqJJht45Ia//Cp2dHxK j0p1gbHKs/nJLGaL+j0W49azGF4/5TIt7aVu0RB92esAdmFA3m6wktYUxK2ymYTlkCC+ tLCaZ4QvLf8S3kPw6So4nP2+AuR9FJqC+Z4wHhSy8N2nrmVi7M3SE/t/XtZwLV5h05og DALAWPkwzfuUMYqBAfzoHkiZCGR9Fv8ZiqjcQIHT3riEuJ8M5z3XsQI1hPfNbL7Qg7vn ZMag== X-Gm-Message-State: AOJu0YwQiYsbrwM8JwdYVVVPT6Eqp3FDdEZu7svkXbfB4vkHo2bSIGhC wssnKWv3tqw6jG/1G1+JZn26vBw4rkByrpUOkxtfkf8KrOC3CfPKLMBEGhhkdnweJcsbqZVT1CT +6eEivWqOoDFEI7L0pSStRH/ZMpBJWJPj/OAd2bhHDGiNJVLYpHI8c6WPvrD9OEXp1xSMpIcWkZ 3CqScIWGKMfsuQxYvv8CnK705rSF82ycPmRPRKzApQdyMhmA== X-Received: by 2002:a05:6e02:1807:b0:363:792c:ac43 with SMTP id a7-20020a056e02180700b00363792cac43mr3605310ilv.3.1706724578489; Wed, 31 Jan 2024 10:09:38 -0800 (PST) Received: from localhost.localdomain ([2620:11a:c018:0:ea8:be91:8d1:f59b]) by smtp.gmail.com with ESMTPSA id v24-20020a634818000000b005cfbf96c733sm10876004pga.30.2024.01.31.10.09.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Jan 2024 10:09:38 -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 1/3] eventpoll: support busy poll per epoll instance Date: Wed, 31 Jan 2024 18:08:03 +0000 Message-Id: <20240131180811.23566-2-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-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1789630519784839771 X-GMAIL-MSGID: 1789630519784839771 Allow busy polling on a per-epoll context basis. The per-epoll context usec timeout value is preferred, but the pre-existing system wide sysctl value is still supported if it specified. Note that this change uses an xor: either per epoll instance busy polling is enabled on the epoll instance or system wide epoll is enabled. Enabling both is disallowed. Signed-off-by: Joe Damato --- fs/eventpoll.c | 49 +++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 4 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 3534d36a1474..ce75189d46df 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -227,6 +227,8 @@ struct eventpoll { #ifdef CONFIG_NET_RX_BUSY_POLL /* used to track busy poll napi_id */ unsigned int napi_id; + /* busy poll timeout */ + u64 busy_poll_usecs; #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -386,12 +388,44 @@ static inline int ep_events_available(struct eventpoll *ep) READ_ONCE(ep->ovflist) != EP_UNACTIVE_PTR; } +/** + * busy_loop_ep_timeout - check if busy poll has timed out. The timeout value + * from the epoll instance ep is preferred, but if it is not set fallback to + * the system-wide global via busy_loop_timeout. + * + * @start_time: The start time used to compute the remaining time until timeout. + * @ep: Pointer to the eventpoll context. + * + * Return: true if the timeout has expired, false otherwise. + */ +static inline bool busy_loop_ep_timeout(unsigned long start_time, struct eventpoll *ep) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + unsigned long bp_usec = READ_ONCE(ep->busy_poll_usecs); + + if (bp_usec) { + unsigned long end_time = start_time + bp_usec; + unsigned long now = busy_loop_current_time(); + + return time_after(now, end_time); + } else { + return busy_loop_timeout(start_time); + } +#endif + return true; +} + #ifdef CONFIG_NET_RX_BUSY_POLL +static bool ep_busy_loop_on(struct eventpoll *ep) +{ + return !!ep->busy_poll_usecs || net_busy_loop_on(); +} + static bool ep_busy_loop_end(void *p, unsigned long start_time) { struct eventpoll *ep = p; - return ep_events_available(ep) || busy_loop_timeout(start_time); + return ep_events_available(ep) || busy_loop_ep_timeout(start_time, ep); } /* @@ -404,7 +438,7 @@ static bool ep_busy_loop(struct eventpoll *ep, int nonblock) { unsigned int napi_id = READ_ONCE(ep->napi_id); - if ((napi_id >= MIN_NAPI_ID) && net_busy_loop_on()) { + 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); if (ep_events_available(ep)) @@ -430,7 +464,8 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi) struct socket *sock; struct sock *sk; - if (!net_busy_loop_on()) + ep = epi->ep; + if (!ep_busy_loop_on(ep)) return; sock = sock_from_file(epi->ffd.file); @@ -442,7 +477,6 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi) return; napi_id = READ_ONCE(sk->sk_napi_id); - ep = epi->ep; /* Non-NAPI IDs can be rejected * or @@ -466,6 +500,10 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi) { } +static inline bool ep_busy_loop_on(struct eventpoll *ep) +{ + return false; +} #endif /* CONFIG_NET_RX_BUSY_POLL */ /* @@ -2058,6 +2096,9 @@ static int do_epoll_create(int flags) error = PTR_ERR(file); goto out_free_fd; } +#ifdef CONFIG_NET_RX_BUSY_POLL + ep->busy_poll_usecs = 0; +#endif ep->file = file; fd_install(fd, file); return fd;