Re: [PATCH 6/6] ARM: Inline locking functions for !PREEMPTION

Sebastian Andrzej Siewior
2019-10-15T22:04:45Z

On 2019-10-14 09:43:53 [+0200], Arnd Bergmann wrote:
> On Mon, Oct 14, 2019 at 12:14 AM Sebastian Andrzej Siewior
> <sebastian@breakpoint.cc> wrote:
> >
> > On non-preemptive kernels, the locking instruction is less than 64 bytes
> > and it makes sense to inline it. With PREEMPTION the kernel becomes very
> > big if the locks are inlined.
> >
> > Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
> > ---
>
> At the moment, we have two architectures selecting all 28 symbols
> and you are adding a third, all other architecture select none of them.
>
> This tells me that the configurability has gone a little overboard. How about
> adding a shortcut ARCH_INLINE_ALL_SPINLOCKS that selects the 28
> symbols and using that for arm/arm64/s390?

Sounds reasonable.

> Also, the output of 'size vmlinux' before and after the patch for
> multi_v7_defconfig would be useful to have in the changelog, as there
> are a couple of platforms that are particularly sensitive to object code
> size changes.

okay.

> Arnd

Sebastian