From patchwork Thu Jan 4 02:47:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Soheil Hassas Yeganeh X-Patchwork-Id: 855351 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="NgUKbfwn"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zBsfy4vbmz9s7M for ; Thu, 4 Jan 2018 13:48:10 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752129AbeADCsH (ORCPT ); Wed, 3 Jan 2018 21:48:07 -0500 Received: from mail-yw0-f193.google.com ([209.85.161.193]:45778 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751991AbeADCsG (ORCPT ); Wed, 3 Jan 2018 21:48:06 -0500 Received: by mail-yw0-f193.google.com with SMTP id y187so122702ywd.12 for ; Wed, 03 Jan 2018 18:48:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=dwA6AgJUhhmKfulcXx4uFOLV3UvfuW5CJxsWR2eHvsA=; b=NgUKbfwn4VbXLSu8TaU5T+nJnq3+lYCozYuLqFitjU28BnfNKGTT0LYUkpn7zF3dRS ix/LN8n2FwgqQJasg06wUx/SZme4FPJ2xo+zpMAfYUYsyp51qXWOtbFgtJWitz7d5qEN /mArc3/61b8UeLQT+bbzRyLmR8JYxp/MIWCm+UkSSdQIcceU/ike+IJHPFxem48U6ssT 0MLM/bD7XDr8AI9b3/TYGrhlrtR88SwUzKNfKwLEOETzgoYbFAlqva09aA0SdL7GmJ5h 4lt4nAGqv8NSoI9ZCkhndVi6RTXrzeliFBgI0mJRKOg4rQv2bhcVneFlGNiZ3mJ4r0gR 2ONg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=dwA6AgJUhhmKfulcXx4uFOLV3UvfuW5CJxsWR2eHvsA=; b=VCNIDSCr7dVlD8NjScxZGmGmpSfIj+2Edkth/Y4zrPEFCiWL0YhjBtAAwUYpBlUz97 MfcXnY8lUlxOKP8W+MeyrZH/FJuyDvJSWpx9d+JmoClIhiRY9FtBYS6pBx8rqQZgAoK2 6MF8p5i9wNjMVlciK6JL4qJLTeKkW4TzlQ7ZN9duBNesvyWUlDkTjKv1OUZ70qeJVsXc ft6dMh7RKpu6hQBL21VV+7RqIEPrxtVzTHLU9I9Txdn4w8nXGwh9/JGtUPnoCMjJf96F UYW1tklTy6eQqRX2YwgvsNf96xbNuriZTkNbV4ryoF7w6kszRpcAqPPRdiFu5dsNktD7 koaw== X-Gm-Message-State: AKGB3mJv+X9uLVp8HkCpfBtEiJWDLM73heveRSyAIGGQuZsGIYJnbyUI 4nLzdmdKiyIDcSM0GCCmi0k= X-Google-Smtp-Source: ACJfBotOytrtPlYuHo3QWl+mdMOPg4My1t4ia8WH5FQoeN+HJOB881BAisSBgfFqY40POs4FKaHw1g== X-Received: by 10.13.214.206 with SMTP id y197mr3267582ywd.318.1515034085609; Wed, 03 Jan 2018 18:48:05 -0800 (PST) Received: from z.nyc.corp.google.com ([2620:0:1003:315:e2bf:c27f:ff24:b1be]) by smtp.gmail.com with ESMTPSA id w5sm1045646ywl.108.2018.01.03.18.48.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Jan 2018 18:48:05 -0800 (PST) From: Soheil Hassas Yeganeh To: davem@davemloft.net, netdev@vger.kernel.org Cc: pjt@google.com, ycheng@google.com, Soheil Hassas Yeganeh , Willem de Bruijn , Eric Dumazet , Neal Cardwell Subject: [PATCH net-next 1/2] ip: do not set RFS core on error queue reads Date: Wed, 3 Jan 2018 21:47:10 -0500 Message-Id: <20180104024711.257600-1-soheil.kdev@gmail.com> X-Mailer: git-send-email 2.16.0.rc0.223.g4a4ac83678-goog Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Soheil Hassas Yeganeh We should only record RPS on normal reads and writes. In single threaded processes, all calls record the same state. In multi-threaded processes where a separate thread processes errors, the RFS table mispredicts. Note that, when CONFIG_RPS is disabled, sock_rps_record_flow is a noop and no branch is added as a result of this patch. Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Willem de Bruijn Signed-off-by: Eric Dumazet Signed-off-by: Neal Cardwell --- net/ipv4/af_inet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index bab98a4fedad..54cccdd8b1e3 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -790,7 +790,8 @@ int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int addr_len = 0; int err; - sock_rps_record_flow(sk); + if (likely(!(flags & MSG_ERRQUEUE))) + sock_rps_record_flow(sk); err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len);