[U-Boot] Fwd: Parallel build is broken

[Bin Meng]

Hi Andy,

On Wed, Sep 5, 2018 at 5:43 AM Tom Rini <trini at konsulko.com> wrote:
>
> On Tue, Sep 04, 2018 at 09:05:55PM +0300, Andy Shevchenko wrote:
> > On Tue, Sep 4, 2018 at 9:00 PM Tom Rini <trini at konsulko.com> wrote:
> > >
> > > On Tue, Sep 04, 2018 at 07:33:10PM +0300, Andy Shevchenko wrote:
> > > > On Tue, Sep 4, 2018 at 6:47 PM Andy Shevchenko
> > > > <andy.shevchenko at gmail.com> wrote:
> > > > >
> > > > > On Tue, Sep 4, 2018 at 6:14 PM Tom Rini <trini at konsulko.com> wrote:
> > > > > > On Tue, Sep 04, 2018 at 05:50:33PM +0300, Andy Shevchenko wrote:
> > > > > > > On Tue, Sep 4, 2018 at 5:00 PM Tom Rini <trini at konsulko.com> wrote:
> > > > > > > > On Tue, Sep 04, 2018 at 03:42:05PM +0300, Andy Shevchenko wrote:
> > > > >
> > > > > > > make clean && make edison_defconfig && make -j16
> > > > > > >
> > > > > > > gcc (Debian 8.2.0-4) 8.2.0
> > > > > > > Copyright (C) 2018 Free Software Foundation, Inc.
> > > > > > > This is free software; see the source for copying conditions.  There is NO
> > > > > > > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> > > > > >
> > > > > > I assume this is on Debian/unstable?
> > > > >
> > > > > testing
> > > > >
> > > > > >  I can't directly replicate this on
> > > > > > my 24core (Debian/stretch) or 16core(Ubuntu/xenial) machines.  I'll
> > > > > > setup a chroot soon, but since you've said -j64 is fine there too I
> > > > > > suspect you have more cores than I.  This may be something you have to
> > > > > > bisect for us if I can't replicate it myself.  Can you confirm how many
> > > > > > cores you have?  I might be able to spin something up in Google compute.
> > > > >
> > > > > $ sed -n -e '/cpu cores/ { p; q }' /proc/cpuinfo
> > > > > cpu cores       : 22
> > > >
> > > > Did few runs (~6) on this machine with -j4, no failures so far.
> > > > Reruning same with -j16 brings failure on ~2-3 iteration.
> > > >
> > > > It seems the scope can be narrowed to:
> > > > - many cores build system, and
> > > > - Debian testing/unstable toolchain, and/or
> > > > - U-Boot build system
> > >
> > > I'm pretty sure it's a dependency problem somewhere.  Since this was
> > > working reliably for you recently (right?) and I can't reproduce it and
> > > you can, if you can run a git bisect to figure out what commit is
> > > breaking things, that would be very helpful.  Thanks!
> >
> > Now after my vacation.
> > So, I guess it's not so critical for release as I thought at the beginning.
>
> I'd love to fix it, but I can't replicate it.

I can't reproduce this on my machine too, on Ubuntu 16.04 with either
native gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.10), or
the kernel.org gcc (gcc version 7.3.0 (GCC)), using below commands:

$ make clean && make edison_defconfig && make -j64

Regards,
Bin