Re: arm/arm64 perf build issue with mainline

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Mon, May 11, 2015 at 06:29:28PM +0100, Will Deacon escreveu:
> On Mon, May 11, 2015 at 04:59:58PM +0100, acme@redhat.com wrote:
> > Em Mon, May 11, 2015 at 12:58:14PM -0300, acme@redhat.com escreveu:
> > > Em Mon, May 11, 2015 at 02:33:04PM +0200, Ingo Molnar escreveu:
> > > > > That was already proposed here (as part of the fallback from getconf):
> > > > > 
> > > > >   https://lkml.kernel.org/r/20150427190356.GD474@krava.redhat.com
> > > > > 
> > > > > but I'm not sure what happened to the patch.
> > > > 
> > > > Sending out the latest/best version as a reminder for Arnaldo will 
> > > > sure help it along.
> > > > 
> > > > Acked-by: Ingo Molnar <mingo@kernel.org>
> > > 
> > > IIRC it was merged already, lemme check...
> > 
> > Yes, only for perf/core:
> 
> Ah, that explains why I couldn't see it in my tree. Could we get it in
> for 4.1 please, as this is a regression for arm/arm64 (where the
> auto-detection used to work fine)?

Ok, I'll cherry-pick it into a perf/urgent branch, will see if there are
more cherries and then ask Ingo to pull it.

- Arnaldo
 
> Cheers,
> 
> Will
> 
> > 
> > [acme@zoo linux]$ git show 762abdc0c6c013425958cd9f5105f4e32268d434
> > commit 762abdc0c6c013425958cd9f5105f4e32268d434
> > Author: Will Deacon <will.deacon@arm.com>
> > Date:   Thu Apr 23 15:00:16 2015 +0100
> > 
> >     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@arm.com>
> >     Acked-by: Jiri Olsa <jolsa@kernel.org>
> >     Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> >     Cc: David Ahern <david.ahern@oracle.com>
> >     Cc: Mark Rutland <Mark.Rutland@arm.com>
> >     Cc: Namhyung Kim <namhyung@kernel.org>
> >     Link: http://lkml.kernel.org/r/20150423140454.GJ1652@arm.com
> >     [ Made it fall back to parsing /proc when getconf not found ]
> >     Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> > 
> > diff --git a/tools/perf/Makefile b/tools/perf/Makefile
> > index c699dc35eef9..d31a7bbd7cee 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
> > [acme@zoo linux]$ 
> >