Re: [patch] generic-ipi: remove kmalloc, cleanup

[Rusty Russell]

On Saturday 14 February 2009 10:18:05 Peter Zijlstra wrote:
> On Sat, 2009-02-14 at 07:46 +1030, Rusty Russell wrote:
> > I'd be fascinated to see perf numbers once you kill the kmalloc.  Because
> > this patch will add num_possible_cpus * NR_CPUS/8 bytes to the kernel which
> > is something we're trying to avoid unless necessary.
> 
> You're free to make it a pointer and do node affine allocations from an
> init section of choice and add a hotplug handler.
> 
> But I'm not quite sure how perf is affected by size overhead on
> ridiculous configs.

No, I meant "can you actually measure the perf win of this patch?".  If you
did so, I missed it?

But if this patch is worthwhile, the right way to do this is make it a
cpumask_var_t, and do the alloc_cpumask_var_node() in that init routine.

Thanks,
Rusty.
--
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/