[PATCH xserver 0/3] Fix O(n*m) performance cliff in miarc

Adam Jackson ajax at redhat.com
Thu Mar 2 20:45:59 UTC 2017

On Wed, 2017-03-01 at 15:20 -0800, Keith Packard wrote:
> > Adam Jackson <ajax at redhat.com> writes:
> > So, way back in 946f664b, I removed a cache from the miarc code, with the
> > justification that arcs were rare and the performance improvement wasn't
> > worth it. I'd have been more right if the miarc code wasn't, what's the
> > word, garbage.
> Hey, that's some of my finest code from 1989 you're messing with...

I assume this is meant in the same sense that The Onion is America's
Finest News Source.

> > Rather than reintroduce the cache, this series holds on to the span data
> > for the duration of a single pass through the arc. So we'll still compute
> > things twice for double-dashed arcs, but that's still down in the "small
> > numbers of milliseconds per arc in the worst case" regime.
> Reviewed-by: Keith Packard <keithp at keithp.com>

remote: E: failed to find patch for rev 9426c5500b72e1fe004fef4c3b259023c4ec49f7.
remote: I: patch #141523 updated using rev 849c825855b82caf44d25edb8155bc9f17869256.
remote: I: patch #141524 updated using rev 0d7f05ed99b71a4641415c9f26e245c3bb24a9a0.
remote: I: 2 patch(es) updated to state Accepted.
To ssh://git.freedesktop.org/git/xorg/xserver
   fe5c340..0d7f05e  master -> master

- ajax

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