Re: [PATCH] net: force dst_default_metrics to const section

[Eric Dumazet <eric.dumazet@gmail.com>]

On Tue, 2012-08-07 at 23:12 +0100, Ben Hutchings wrote:
> On Tue, 2012-08-07 at 22:55 +0200, Eric Dumazet wrote:
> > From: Eric Dumazet <edumazet@google.com>
> > 
> > 
> > > Some day the compiler may be smart enough to ignore the different
> > > between explicit and implicit zero-initialisation, and put it back in
> > > BSS.  Declaring this __cache_aligned_in_smp might be a better option.
> > 
> > __cache_aligned_in_smp aligns start of the structure, but can be
> > followed by another var in same cache line. Yes, this is bad.
> 
> Oh, that's unexpected.
> 
> > By the way we dont care of cache alignment on this structure, only it
> > should be const. Its a soft requirement, machine wont crash if it is not
> > the case.
> 
> Right.
> 
> > If compiler is smart one day as you say (it should first be non buggy
> > IMHO), then we can add a non zero field like this :
> [...]
> 
> That would work, but it's ugly!  How about defining and using a
> meaningfully-named macro that expands to __section(.rodata)?

You are kidding. I prefer plain C and not having to mess with all
arches.