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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Thu, 29 Apr 2021 19:22:27 -0700
Message-ID: <CAKwvOdk+V2dc31guafFM=N2ez4SrwCmah+mimUG3MzPMx_2efQ@mail.gmail.com>
Subject: Re: Very slow clang kernel config ..
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>
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On Thu, Apr 29, 2021 at 5:19 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Thu, Apr 29, 2021 at 2:53 PM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > I haven't looked into why this is so slow with clang, but it really is
> > painfully slow:
> >
> >    time make CC=clang allmodconfig
> >    real 0m2.667s
> >
> > vs the gcc case:
> >
> >     time make CC=gcc allmodconfig
> >     real 0m0.903s
>
> Can
> you provide info about your clang build such as the version string,
> and whether this was built locally perhaps?

d'oh it was below.

> > This is on my F34 machine:
> >
> >      clang version 12.0.0 (Fedora 12.0.0-0.3.rc1.fc34)

-- 
Thanks,
~Nick Desaulniers