From patchwork Thu Nov 12 19:02:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arjun Roy X-Patchwork-Id: 1399258 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=mMdZq0Tq; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CX9wd26Zjz9s0b for ; Fri, 13 Nov 2020 06:03:13 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727196AbgKLTDK (ORCPT ); Thu, 12 Nov 2020 14:03:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726759AbgKLTDA (ORCPT ); Thu, 12 Nov 2020 14:03:00 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CCAFC0613D4 for ; Thu, 12 Nov 2020 11:02:59 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id v12so5375575pfm.13 for ; Thu, 12 Nov 2020 11:02:59 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=fMyNeyMIQsirgjnCDGnyYpd6LU6jKA1eMXSUgYknCfA=; b=mMdZq0TqbhvbECFPkP5NrcF27u8ZaM+0BT7pGvEgWLZw+S4Ro96+qcXTgx5c8Ed9ZY MQA8IgpdmTrU3FFDiy0Uy22uXqfpCKoYpKv39CfBUEhhU00nvG0CQiCANJrbf9e/rUxC DOhg236RXtfTRKxacbanc3Srw9fdOEoNGGPLe8vQ/JpGk5iDuou29TgeJIF8e1eGUDTi 8X5Zg7Bk/X4wBr/Z9Zaccn69GWyvOz2qiKugw5uZ0QbQnsIq65r+8BRPoazn7lElKcIU kqw9+XWv3f0T9rkPsU36tJy+YNe4obxgOq4fwqA0xP1DDq79lu/SweLTWbkHgLW9Al+o ZPHw== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=fMyNeyMIQsirgjnCDGnyYpd6LU6jKA1eMXSUgYknCfA=; b=Sib/S5mxLXV9XNIggA0k2CgGWkH9brsqB287cYNQa8QfHzF7/BxGb6oYlxrHemTkSL w17lyamcvPOlF5KrQ8tHYzMkwhDwjo1IyGEANcr9cICrc54OugSOJeDYGYAM2aKwx00e jZ4sCgjRghM0nSi2WMm86NFfOnIGaKXpGsEIOrJCJs1IQYmBhkbDVCr/DUXCR9Yjjctw OJCoOIjTxIkpb8NlAstFPa5pLOSLs4E6/sLt0tSxdkucDodtaDW83UzlfeEIrMaEPucQ a3A0F2yX1u5VjYGp0yqUHrLC+SE5u5QSbTqk/8X7iixHS18GiqdoAX4ivJEQ+cu4qb7S e83Q== X-Gm-Message-State: AOAM533bdme8uMvxYOpdfkNy0BJnZhHQ1jx7FPBfSk+mnxVoWJ8q227u 4LB8gextbdBFi27od46Nn4o= X-Google-Smtp-Source: ABdhPJwC2RgJ1FH0a2O+NqqX59YSlLjb4439DSuUKbP/LrSyBizn4tpwrFFZl0lZddqo5T5xTXgRyA== X-Received: by 2002:a63:fc1c:: with SMTP id j28mr720539pgi.95.1605207779125; Thu, 12 Nov 2020 11:02:59 -0800 (PST) Received: from phantasmagoria.svl.corp.google.com ([2620:15c:2c4:201:f693:9fff:feea:f0b9]) by smtp.gmail.com with ESMTPSA id z7sm7458809pfq.214.2020.11.12.11.02.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2020 11:02:58 -0800 (PST) From: Arjun Roy To: davem@davemloft.net, netdev@vger.kernel.org Cc: arjunroy@google.com, edumazet@google.com, soheil@google.com Subject: [net-next 5/8] tcp: Fast return if inq < PAGE_SIZE for recv zerocopy. Date: Thu, 12 Nov 2020 11:02:02 -0800 Message-Id: <20201112190205.633640-6-arjunroy.kdev@gmail.com> X-Mailer: git-send-email 2.29.2.222.g5d2a92d10f8-goog In-Reply-To: <20201112190205.633640-1-arjunroy.kdev@gmail.com> References: <20201112190205.633640-1-arjunroy.kdev@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Arjun Roy Sometimes, we may call tcp receive zerocopy when inq is 0, or inq < PAGE_SIZE, in which case we cannot remap pages. In this case, simply return the appropriate hint for regular copying without taking mmap_sem. Signed-off-by: Arjun Roy Signed-off-by: Eric Dumazet Signed-off-by: Soheil Hassas Yeganeh --- net/ipv4/tcp.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f3bd606a678d..38f8e03f1182 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1885,6 +1885,14 @@ static int tcp_zerocopy_receive(struct sock *sk, sock_rps_record_flow(sk); + if (inq < PAGE_SIZE) { + zc->length = 0; + zc->recv_skip_hint = inq; + if (!inq && sock_flag(sk, SOCK_DONE)) + return -EIO; + return 0; + } + mmap_read_lock(current->mm); vma = find_vma(current->mm, address);