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

Andrew Morton wrote:

"David S. Miller" wrote:

quoted

   From: Andrew Morton [off-list ref]
   Date: Sat, 07 Dec 2002 15:29:16 -0800

   Jeff Garzik wrote:
   > Attached is cut #2.  Thanks for all the near-instant feedback so far :)
   >   Andrew, does the attached still need padding on SMP?

   It needs padding _only_ on SMP.  ____cacheline_aligned_in_smp.

non-smp machines lack L2 caches?  That's new to me :-)

More seriously, there are real benefits on non-SMP systems.

Then I am most confused.  None of these fields will be put under
busmastering or anything like that, so what advantage is there in
spreading them out?

Oh I see what you want - to be able to pick up all the operating fields
in a single fetch.

That will increase the overall cache footprint though.  I wonder if
it's really a net win, over just keeping it small.