Messages in this thread Patch in this message | | | Date | Thu, 23 Apr 2015 15:04:54 +0100 | From | Will Deacon <> | Subject | Re: arm/arm64 perf build issue with mainline |
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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 $(ARCH) being sparc?
Scratch that, how about using sysconf instead? Patch below...
Will
--->8
From 28740111e81aa9247bf48e3125dc43cc31d94e6f Mon Sep 17 00:00:00 2001 From: Will Deacon <will.deacon@arm.com> Date: Thu, 23 Apr 2015 15:00:16 +0100 Subject: [PATCH] tools: perf: use getconf to determine number of online CPUs
Parsing /proc/cpuinfo is a fiddly, arch-dependent business anda recent change to get it working for Sparc broke arm and arm64 platforms.
Instead, use sysconf to determine the number of online CPUs and avoid parsing /proc/cpuinfo entirely.
Signed-off-by: Will Deacon <will.deacon@arm.com> --- tools/perf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/Makefile b/tools/perf/Makefile index c699dc35eef9..c26cb04ce6bd 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -24,7 +24,7 @@ unexport MAKEFLAGS # (To override it, run 'make JOBS=1' and similar.) # ifeq ($(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
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