negative performance speedup with -fno-plt

[Farid Zakaria]

Thank you everyone for the advice.
I'm not familiar with localplt but I took the advice to not look into
glibc without PLT for now.

To add more information for those curious:
I ran rubybench without a PLT also and recorded the following
performance https://pasteboard.co/290D6T0kffzl.png
(blue line is the geomean)

On Mon, Sep 16, 2024 at 5:25 PM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Farid Zakaria:
>
> > Thank you for the advice; I will look into that with perf if it has statistics.
> >
> > I noticed also that I had only built python + libpython without a PLT
> > but glibc itself continued to have a PLT
> > (I'm using NixOS to make changes).
> >
> > Looks like trying to override CFLAGS to build glibc without PLT is
> > challenging; it didn't like me just setting CFLAGS :)
>
> Passing CC="gcc -fno-plt" should work for building, but there will be
> new test suite failures due to -fno-plt.
>
> Thanks,
> Florian
>