Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965573AbbDWOE7 (ORCPT ); Thu, 23 Apr 2015 10:04:59 -0400 Received: from foss.arm.com ([217.140.101.70]:51261 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756206AbbDWOE6 (ORCPT ); Thu, 23 Apr 2015 10:04:58 -0400 Date: Thu, 23 Apr 2015 15:04:54 +0100 From: Will Deacon To: "david.ahern@oracle.com" Cc: "linux-kernel@vger.kernel.org" , Mark Rutland , "jolsa@kernel.org" , "namhyung@kernel.org" , "acme@redhat.com" Subject: Re: arm/arm64 perf build issue with mainline Message-ID: <20150423140454.GJ1652@arm.com> References: <20150423112916.GF1652@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150423112916.GF1652@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2016 Lines: 64 On Thu, Apr 23, 2015 at 12:29:16PM +0100, Will Deacon wrote: > Hi all, > > Commit 6428c59a97de ("perf tools: Set JOBS based on CPU or processor") > causes weird behaviour on arm/arm64 platforms because we use the "CPU" > prefix for things like: > > CPU implementer : 0x41 > CPU architecture: 8 > CPU variant : 0x0 > CPU part : 0xd03 > CPU revision : 0 > > in /proc/cpuinfo. Consequently, a 6 core machine ends up doing: > > will@confinement-loaf:~/linux/tools/perf$ make > BUILD: Doing 'make -j36' parallel build > > which is a little overwhelming. Any chance we can predicate the extra > part of the regex on $(ARCH) being sparc? Scratch that, how about using sysconf instead? Patch below... Will --->8 >From 28740111e81aa9247bf48e3125dc43cc31d94e6f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 23 Apr 2015 15:00:16 +0100 Subject: [PATCH] tools: perf: use getconf to determine number of online CPUs Parsing /proc/cpuinfo is a fiddly, arch-dependent business anda recent change to get it working for Sparc broke arm and arm64 platforms. Instead, use sysconf to determine the number of online CPUs and avoid parsing /proc/cpuinfo entirely. Signed-off-by: Will Deacon --- tools/perf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/Makefile b/tools/perf/Makefile index c699dc35eef9..c26cb04ce6bd 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -24,7 +24,7 @@ unexport MAKEFLAGS # (To override it, run 'make JOBS=1' and similar.) # ifeq ($(JOBS),) - JOBS := $(shell egrep -c '^processor|^CPU' /proc/cpuinfo 2>/dev/null) + JOBS := $(shell getconf _NPROCESSORS_ONLN 2>/dev/null) ifeq ($(JOBS),0) JOBS := 1 endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/