Re: [patch] tlb flush_data: replace per_cpu with an array

[Ingo Molnar]

* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > -	char pad[SMP_CACHE_BYTES];
> > -} ____cacheline_aligned;
> > +	char pad[X86_INTERNODE_CACHE_BYTES];
> > +} ____cacheline_internodealigned_in_smp;
> 
> That will make the below array 8*4096 bytes for VSMP, which pushes the 
> limit for memory savings up to 256 cpus.

VSMP is a clustering solution (default-disabled) that pushes 
L1_CACHE_BYTES to 4096 bytes (4K). That is an extremely large alignment 
that pushes up the BSS size ten-fold (!), so no generic Linux distribution 
enables it. 32K compared to 9MB bloat caused by 4K cachelines is a drop in 
the ocean.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/