Re: [PATCH 0/2] pipe: Fixes [ver #2]

[Akemi Yagi]

On 12/6/19 10:59 AM, Linus Torvalds wrote:
> Hmm. I think I just saw this same bug with a plain kernel compile.
>
> My "make -j32" suddenly came to a crawl, and seems to be entirely
> single-threaded.
>
> And that's almost certainly because the way 'make' handles load
> distribution is with a network of pipes that has a token passed to the
> sub-makes.
>
> So there's most definitely something wrong with the new pipe rework.
> Well, I can't _guarantee_ the pipes are the cause of this, but it does
> smell like it.
>
>                Linus

We encountered what seems to be the same problem when building a kernel
under RHEL 8.

As it turned out, this was due to a bug in make (make-4.2.1-9.el8) and
a patch is available. Details are found in this Red Hat bugzilla report:

https://bugzilla.redhat.com/show_bug.cgi?id=1774790

Akemi