Comment 239 for bug 541511

Created an attachment (id=35548)
v9 against latest drm-intel-next

Sorry for the delay, but I want to test new patches a little before posting (especially now that quite a few people are on this bugs cc list). Changes vs v8:

- rebased against latest drm-intel-next (patch shrunk quite decently, yeah!).
- increased the gtt flock size to 16 pages. Perhaps this helps.

Plans going forward:
- I haven't yet started on the performance work. I don't really like mucking around in a very delicate and hard to debug part of gem. So I still hope that this problem somehow magically fixes itself ;) More honestly: Correctnes first, performance later (and if I'm very lucky, other ongoing work by other people will make this much easier).
- Merging plans: Due to the (new) failures reported with v8 I'm reluctant to submit the patch as-is. I'm definitely pushing everything up to the cache coherency checker for inclusion into -next (already submitted). But the actual fix probably needs to wait some more.
- I haven't yet had time to research/implement the RAM bank idea by rainy6144.