Re: [PATCH v4 13/13] riscv: Add qspinlock support

Andrew Jones
2024-08-21T12:18:13Z

On Sat, Aug 17, 2024 at 01:08:34PM GMT, Guo Ren wrote:
...
> > So I have just checked the size of the jump table section:
> >
> > * defconfig:
> >
> > - ticket: 26928 bytes
> > - combo: 28320 bytes
> >
> > So that's a ~5% increase.
> >
> > * ubuntu config
> >
> > - ticket: 107840 bytes
> > - combo: 174752 bytes
> >
> > And that's a ~62% increase.
> The size of the jump table section has increased from 5% to 62%. I
> think some configuration triggers the jump table's debug code. If it's
> not a debugging configuration, that's a bug of the Ubuntu config.

And I just remembered we wanted to check with CONFIG_CC_OPTIMIZE_FOR_SIZE

Thanks,
drew

>
> >
> > This is the ELF size difference between ticket and combo spinlocks:
> >
> > * ticket: 776915592 bytes
> > * combo: 786958968 bytes
> >
> > So that's an increase of ~1.3% on the ELF.
> >
> > And the .text section size:
> >
> > * ticket: 12290960 bytes
> > * combo: 12366644 bytes
> >
> > And that's a ~0.6% increase!
> >
> > Finally, I'd say the impact is very limited :)
> >
> > Thanks,
> >
> > Alex
> >
> >