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=-2.7 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 E2DE620281 for ; Tue, 23 May 2017 19:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764518AbdEWTZj (ORCPT ); Tue, 23 May 2017 15:25:39 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:34178 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764475AbdEWTZc (ORCPT ); Tue, 23 May 2017 15:25:32 -0400 Received: by mail-wm0-f66.google.com with SMTP id d127so41724493wmf.1 for ; Tue, 23 May 2017 12:25:31 -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 :in-reply-to:references:mime-version:content-transfer-encoding; bh=ykQacloswLh2YDreKNNHuZUlrBWbu4iwtdD41KXcAz4=; b=SmFTtmEAJLO/ErC++nPygltG4/tm0UmMi7etc13e/t8U/G8iNHYOpEV2l8OjsmFZ2n 56BItyI2L6D/0gppNwzTJbQ6JfK7JDDyZkbZ1vfpbHyf8PC9AY31TOJ2rnp8vnm9qfw0 FaeyXYTLPCkr/OS4JrmiRqzZFFhMKWHAo28yzJKmh7tpZAhSISV7PZyKZi1qlfEg/t/H +UdrOShZKLlCwILCTvwC80B/zervIqZvLBTDk1L7n0gBnhggMPCpatofKWvysc1UZmDe UEGd1MKZtJqegheLtTQSXDpvyMhaIxzqTRrOdc5bMr6so+4HIr92TA16m4Yvq5hzR87j P32A== 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:in-reply-to:references:mime-version :content-transfer-encoding; bh=ykQacloswLh2YDreKNNHuZUlrBWbu4iwtdD41KXcAz4=; b=qiDKpm3L+j+gP0XD/YZeH+/HDNbeSbcZXxZVdYBidnW7VkSZlCoyoyDE0dix8oQ3cU bPCNHcjuFIYVHMqsjHlreid1/DIIFLQ9CUAFsbr8cnnti5qomj9OJmGo5fn/qg154Mql fB/9MmPvMe3/qdvNCc/p7YYFIaqiznET6cIxbPSDvdyzRCW1dN5gaHJpREqLpAQVtpTC 915wTs1pIc4/hfXBl0RJnNi4wdLI40IpAsEdO2kWu841coFvb+0Drfa334mRpfrKLhNf ZtGnqMklecklokAuQDxdnAKWMvERqCiEIc49uUdj8FI+ld5bDp0sfxFRcUKDKhJr4TnJ o5yA== X-Gm-Message-State: AODbwcApMOV5u9x+Nv6qGgTdFUcaE+uzd9ws+LioKDdAvvkmz7s6Wn7B aK+q8sui8FH10g== X-Received: by 10.28.208.130 with SMTP id h124mr3657824wmg.21.1495567520989; Tue, 23 May 2017 12:25:20 -0700 (PDT) Received: from u.nix.is ([2a01:4f8:190:5095::2]) by smtp.gmail.com with ESMTPSA id a24sm2203480wra.17.2017.05.23.12.25.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 May 2017 12:25:20 -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 , Simon Ruderich , =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Subject: [PATCH v2 2/7] grep: skip pthreads overhead when using one thread Date: Tue, 23 May 2017 19:24:48 +0000 Message-Id: <20170523192453.14172-3-avarab@gmail.com> X-Mailer: git-send-email 2.13.0.303.g4ebf302169 In-Reply-To: <20170523192453.14172-1-avarab@gmail.com> References: <20170523192453.14172-1-avarab@gmail.com> In-Reply-To: References: 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 12e62fcbf3..bd008cb100 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