Re: arm/arm64 perf build issue with mainline

From: Ingo Molnar
Date: Mon May 11 2015 - 08:33:16 EST



* Will Deacon <will.deacon@xxxxxxx> wrote:

> On Mon, May 11, 2015 at 09:21:20AM +0100, Ingo Molnar wrote:
> > * David Ahern <david.ahern@xxxxxxxxxx> wrote:
> > > On 4/23/15 5:29 AM, Will Deacon wrote:
> > > >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?
> >
> > That regex needs to be fixed or replaced with a more robust 'number of
> > CPUs on the system' discovery method.
>
> That was already proposed here (as part of the fallback from getconf):
>
> https://lkml.kernel.org/r/20150427190356.GD474@xxxxxxxxxxxxxxxx
>
> 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@xxxxxxxxxx>

Thanks,

Ingo
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