[PATCH] dix: Reshuffle ScreenRec to pack holes

[Adam Jackson]

On Wed, 2010-05-19 at 12:56 -0700, Keith Packard wrote:
> On Wed, 19 May 2010 14:31:19 -0400, Adam Jackson <ajax at redhat.com> wrote:
> > This eliminates the unused 'id' field (what the eff), and reorders the
> > other data fields to fit packed on both ILP32 and LP64.  ScreenRec
> > shrinks by 64 bytes on LP64 (less on ILP32), and devPrivate just
> > barely squeaks into the first cacheline on LP64 as a bonus.
> 
> Of course, it would be 'really cool' if we could figure out which
> elements of this structure were actually accessed frequently and stick
> them in the same cache line. I'll bet 90% of accesses to this structure
> are function pointers and devPrivates. devPrivate is probably not much
> used as the drivers all need to pull pixmaps out of each window these
> days.

Sufficiently dedicated use of valgrind would tell us this, I bet.

> But, this is way better than what we've got.

Don't commit this yet, I want to pull some of Jamey's suggestions in.

- ajax
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part
URL: <http://lists.x.org/archives/xorg-devel/attachments/20100519/d303b748/attachment.pgp>