ring 0 stalled after bytes_moved_threshold reached - CAPVERDE/HD7770 - TAHITI/W9000
Submitted by Julien Isorce
Assigned to Default DRI bug account
Kernel 4.9 from https://cgit.freedesktop.org/~agd5f/linux/log/?h=amd-staging-4.9 and latest mesa. (same result with drm-next-4.12 branch)
Same result with kernel 4.8 and mesa 12.0.6.
In kernel radeon_object.c::radeon_bo_list_validate, once "bytes_moved > bytes_moved_threshold" is reached (this is the case for 850 bo in the same list_for_each_entry loop), I can see that radeon_ib_schedule emits a fence that it takes more than the radeon.lockup_timeout to be signaled.
In radeon_fence_activity, I checked that the "last_emitted" is the seq number for this last emited fence. And last_seq is equal to last_emitted-1.
Then the next call to ttm_wait_bo blocks (15 * HZ > radeon.lockup_timeout) until gpu lockup which leads to a gpu reset.
Also it seems the fence is signaled by swapper after more than 10 seconds but it is too late. I requires to reduce the "15" param above to 4 to see that.
Is it normal that radeon_bo_list_validate still tries to move the bo if bytes_moved_threshold is reached ? Indeed ttm_bo_validate is always called (it blits from vram to vram).
Is it also normal that ttm_bo_validate is called with evict flag as true once bytes_moved_threshold is reached ?