[tip:perf/urgent] perf tools: Use getconf to determine number of online CPUs

From: tip-bot for Will Deacon
Date: Wed May 13 2015 - 02:25:18 EST


Commit-ID: 466c1eb07f42bd27825af24d86b46d05e5e350b9
Gitweb: http://git.kernel.org/tip/466c1eb07f42bd27825af24d86b46d05e5e350b9
Author: Will Deacon <will.deacon@xxxxxxx>
AuthorDate: Thu, 23 Apr 2015 15:00:16 +0100
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 12 May 2015 18:11:16 -0300

perf tools: Use getconf to determine number of online CPUs

Parsing /proc/cpuinfo is a fiddly, arch-dependent business and a recent
change to get it working for Sparc broke arm and arm64 platforms.

Use sysconf to determine the number of online CPUs only parsing
/proc/cpuinfo when sysconf is not available.

Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: David Ahern <david.ahern@xxxxxxxxxx>
Cc: Mark Rutland <Mark.Rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20150423140454.GJ1652@xxxxxxx
[ Made it fall back to parsing /proc when getconf not found ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index c699dc3..d31a7bb 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 := $(shell (getconf _NPROCESSORS_ONLN || egrep -c '^processor|^CPU[0-9]' /proc/cpuinfo) 2>/dev/null)
ifeq ($(JOBS),0)
JOBS := 1
endif
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