Re: [PATCH 1/3] ARM: EXYNOS: pmu: Constify data tables

[Kukjin Kim]

On 12/10/13 01:15, Tomasz Figa wrote:
> On Tuesday 10 of December 2013 00:11:40 Daniel Kurtz wrote:
> > Hi Tomasz,
> >
> > Thank you for the reviews.
> >
> > On Dec 9, 2013 5:15 AM, "Tomasz Figa"<t.figa@xxxxxxxxxxx>  wrote:
> > > Hi Daniel,
> > >
> > > On Thursday 21 of November 2013 02:21:24 Daniel Kurtz wrote:
> > > > These tables are all immutable, make them const to save 4416 bytes of RAM.
> > > >
> > > > size arch/arm/mach-exynos/pmu.o
> > > >     text          data     bss
> > > >      848          4420       4         // before
> > > >     5264             4       4         // after
> > >
> > > I'm not sure where the mentioned saving of RAM is. Moving data between
> > > sections is not supposed to make it use less memory, I believe.
> >
> > You are correct.  This was my misunderstanding from doing too much
> > work with microcontrollers, where .text sections are accessed in place
> > from FLASH for code and const data, but .data memory is copied from a
> > FLASH section to a second RAM section at init for access at runtime.
> > Most modern Linux systems copy/decompress their code and data sections
> > from external storage to RAM anyway, so there is no actual memory
> > savings (except potentially the compiler may be able to optimize a bit
> > more with the const hint).
> >
> > > Anyway, it's a good practice to mark constant data as const, to disallow
> > > changing them at runtime by mistake, so the patch is fine. Except some
> > > issues I commented on inline.
> >
> > Were there supposed to be inline comments?  I don't see any.
>
> Oops, sorry for this, forgot to remove the last sentence. I initially had
> one question about the constant pointers below, but I read through the
> full code again and answered it myself.
>
> The patch is fine.
>
> Reviewed-by: Tomasz Figa<t.figa@xxxxxxxxxxx>
OK, applied 1 to 3 patches into cleanup.

Thanks,
Kukjin
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