* Make sure available areas are considered to have no eviction cost. This seems
to help for https://bugs.freedesktop.org/show_bug.cgi?id=15513 but I'm afraid
that may just be coincidence.
* Only calculate eviction cost of each area once for each eviction pass.
Safeguard against potential (though unlikely) division by zero.
* Cosmetic enhancements: Name eviction cost related variables 'cost' instead of
'score' to emphasize that smaller values are better, update Doxygen file
comment to the way eviction works now.
Reduce the cost of the inner loop, by keeping a set of pointers to the
first and the last areas in the series, subtracting the cost of the first
area from the score, and adding the cost of the last area while walking
the list. This commit also moves the scanning loop from exaOffscreenAlloc
into a separate function.
Idea by Michel Dänzer.
Replace the current score keeping algorithm with a rolling counter that's
incremented in ExaOffscreenMarkUsed, with the previous value being stored
in the area. exaOffscreenAlloc uses the difference between the counter
value and the value in the area when deciding which area to evict.
It now also takes the size of the areas into account, and favors evicting
smaller areas.
The credit for these ideas goes to Michel Dänzer.
This is a new behavior for version 2.1 of EXA, and only takes effect if the
driver has requested that. Otherwise, the previous behavior remains the same.
corresponding pieces of exa-driver.txt, which were becoming stale.
Hopefully the documentation will stay much more up-to-date this way.
Many thanks to jbarnes for writing exa-driver.txt which was used a lot
in writing this documentation.
when extending the driver interface. The card and accel structures are
merged into the ExaDriverRec, which is to be allocated using
exaDriverAlloc(). The driver structure also grows exa_major and
exa_minor, which drivers fill in and have checked by EXA
(double-checking that the driver really did check that the EXA version
was correct). Removes exaInitCard(), which is replaced by the driver
filling in the rec by hand, and the exaGetVersion() and related
EXA_*VERSION which are replaced by always using the XFree86 loadable
module versioning.
dependencies. It was nearly abstract enough already to be used by
multiple DDXes. This will be useful for EXA development through
providing a fake acceleration implementation within Xephyr, so that
testing can be done on new EXA code without worrying about buggy
drivers.
causing our search loop for evictable blocks to possibly skip a good
candiate, and another was the allocator would occasionally use
area->offset as if it was the base of the pixmap, while for a pixmap
that is not in available state, it is not. This caused some funny
miscalculation leading to overlapping pixmaps and accesses beyond the
end of the framebuffer. To make things cleared, I renamed save_offset
to base_offset, made sure it's the one used everywhere in the
allocator, and only align "offset" for the client at the end of
exaOffscreenAlloc().
than the max, it was bumped, and then if you were above the threshhold
you got moved in. Instead, do the above-threshhold check separate from
score starting out less than max. While this will likely make thrashing
cases worse, I hope it will fix some issues with long term performance
(think of an xcompmgr with a backbuffer it's doing only accelerated
operations to. If some new pixmap comes in and bumps it out, even once,
it will never get a chance to re-migrate because its score will be
maxed). Change migration-out to be the same way for symmetry, though it
shouldn't ever affect anything.
- Fix a lot of debugging output, both in terms of printing quality, and
completeness. The fallback debugging covers a lot more now, pointing
out new areas for improvement. Debugging toggles are now centralized in
exaPriv.h.
