Re: [RFC][PATCH] net drivers and cache alignment

Jeff Garzik (jgarzik@pobox.com)
Sat, 07 Dec 2002 18:36:48 -0500


Andrew Morton wrote:
> It needs padding _only_ on SMP. ____cacheline_aligned_in_smp.
[...]
> So your patch will do what you want it to do. You should just tag the
> first member of a group with ____cacheline_aligned_in_smp, and keep an
> eye on things with offsetof().

thanks.

For this case, though, I want to align on cacheline bounaries even on
UP, right? That's why I picked ____cacheline_aligned. It uses
L1_CACHE_BYTES when !CONFIG_SMP. Other uses of ____cacheline_aligned in
the kernel seem to relate to irq matters, just like my groupings in tg3.h.

[obviously benchmarking can answer some of this, but I want to hammer
out silliness first]

Jeff

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