On Thu, Apr 09, 2015 at 09:00:43PM -0400, Olivier Crête wrote:
Hello,
Using an Atom E3845 board, we had a pretty bad performance regression when upgrading to 4.0-rc6 from 3.19. With the help of git bisect, I traced it back to commit 78a42377. Reverting this commit and subsequent related commits (b9ffd80, 71745376, etc) fixes the performance regression for me.
Can you please test
http://cgit.freedesktop.org/~ickle/linux-2.6/log/?h=for-olivier-crete
on your setup.
First http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=for-olivier-crete&... to get a baseline with nightly as that contains some fine tuning to the batch allocations, which is pretty significant for libva on Atom (only double clflushing one or two pages every batch rather than 128) and then http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=for-olivier-crete&... to see if the command parser tuning helps.
Hope this helps, -Chris