From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.6 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RCVD_IN_SORBS_SPAM, RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 530B920D0A for ; Thu, 1 Jun 2017 18:21:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751201AbdFASVS (ORCPT ); Thu, 1 Jun 2017 14:21:18 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36857 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751167AbdFASVQ (ORCPT ); Thu, 1 Jun 2017 14:21:16 -0400 Received: by mail-wm0-f65.google.com with SMTP id k15so13356037wmh.3 for ; Thu, 01 Jun 2017 11:21:15 -0700 (PDT) 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=h09+9edpFNueJApX/zmHdxbRP8OMzpExmigKEr2YEiU=; b=Cgpi7zFkRFuzb/1D1eQBkdj2NbZn6ca2gWvvQg9hVFpUlDhSsO4Q/WKt6eCoeN2cpz TG2U4Ci/B+Ggo4fH20uXZhLo2d+nSkAZtH8C0x/5BfLwFIfRA0HY1Grzhcs8oLkLlAD5 3Om6PZn/LrwVNIsFS9gwKa/U++WH/eNIDGLyBdi1vCqNYA72587lF6dfqUI7yimi5yd0 WBzt08LiGogFU4ha9F4KoC4fx1R9itdKREqVDBXmoZjeSRNzY5ZGSJyj/J1UcUYBZF5G CWQKgjY7p9RaQzklLWi6Hs79aqfXVrW128KPBA+RZJrepPX/MhwJpJ/80qSh4wiR8gGW +wQw== 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=h09+9edpFNueJApX/zmHdxbRP8OMzpExmigKEr2YEiU=; b=poA+DamKuzDjOQ/4Vnd6jdRsFJOEKhNfFDu+FkRjLnyeAZmH9U5nYmeFxMtIyqVuso a7kqD6IJNxPzpzFfsD7jCkmdI9OdsLBQL3AhBpkEEGxuGwXMquZWrB9GZFQ9LyfXnUKB dryR1gUCHO3C0u8BmONNpM81X1ar6WvPfZWv5DkWdR7kXEGo7a8sRYDR6rL9OxdN6IbO lMy7dH8QraPofEbJLMHIAI0mq9DRrDEnxw0MlhJ7clhcnoHxV0UOyqBC0xJau4SuX0LX iev9C0wLMtKYEGc2GAEhL+NzlH7QCGfBXN4VmbeGMIto/UMqDXWNKceo1aoEnKeLGiiV KPHA== X-Gm-Message-State: AODbwcASODRziKEyE7SeMjdmvWTI1Vb32oBoheQMT+lEr4XbxoVS2Jh0 zyX/FHM+Fnyfo0euKDZl8Q== X-Received: by 10.28.84.67 with SMTP id p3mr372557wmi.40.1496341274162; Thu, 01 Jun 2017 11:21:14 -0700 (PDT) Received: from u.nix.is ([2a01:4f8:190:5095::2]) by smtp.gmail.com with ESMTPSA id 140sm151065wmu.23.2017.06.01.11.21.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Jun 2017 11:21:13 -0700 (PDT) From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= To: git@vger.kernel.org Cc: Junio C Hamano , Jeff King , Jeffrey Walton , =?UTF-8?q?Micha=C5=82=20Kiedrowicz?= , J Smith , Victor Leschuk , =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= , Fredrik Kuivinen , Brandon Williams , Stefan Beller , Johannes Schindelin , =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Subject: [PATCH v4 2/8] grep: skip pthreads overhead when using one thread Date: Thu, 1 Jun 2017 18:20:50 +0000 Message-Id: <20170601182056.31142-3-avarab@gmail.com> X-Mailer: git-send-email 2.13.0.303.g4ebf302169 In-Reply-To: <20170601182056.31142-1-avarab@gmail.com> References: <20170601182056.31142-1-avarab@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Skip the administrative overhead of using pthreads when only using one thread. Instead take the non-threaded path which would be taken under NO_PTHREADS. The threading support was initially added in commit 5b594f457a ("Threaded grep", 2010-01-25) with a hardcoded compile-time number of 8 threads. Later the number of threads was made configurable in commit 89f09dd34e ("grep: add --threads= option and grep.threads configuration", 2015-12-15). That change did not add any special handling for --threads=1. Now we take a slightly faster path by skipping thread handling entirely when 1 thread is requested. Signed-off-by: Ævar Arnfjörð Bjarmason --- builtin/grep.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/builtin/grep.c b/builtin/grep.c index 6e1744550c..a0a3922f92 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -1238,6 +1238,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix) num_threads = GREP_NUM_THREADS_DEFAULT; else if (num_threads < 0) die(_("invalid number of threads specified (%d)"), num_threads); + if (num_threads == 1) + num_threads = 0; #else if (num_threads) warning(_("no threads support, ignoring --threads")); -- 2.13.0.303.g4ebf302169