drm/nouveau: Never evict VRAM buffers to system.
authorFrancisco Jerez <currojerez@riseup.net>
Sat, 6 Mar 2010 12:42:45 +0000 (13:42 +0100)
committerBen Skeggs <bskeggs@redhat.com>
Sun, 14 Mar 2010 23:46:52 +0000 (09:46 +1000)
commit965cf68e8797932e9cd49238a6dd39423ac9b256
tree14dc7963f2b51843458374148ebdb1af672ea9b9
parentd544d623c5ef3ca14407e8bc042fdf938a966b04
drm/nouveau: Never evict VRAM buffers to system.

VRAM->system is a synchronous operation: it involves scheduling a
VRAM->TT DMA transfer and stalling the CPU until it's finished so that
we can unbind the new memory from the translation tables. VRAM->TT can
always be performed asynchronously, even if TT is already full and we
have to move something out of it.

Additionally, allowing VRAM->system behaves badly under heavy memory
pressure because once we run out of TT, stuff starts to be moved back
and forth between VRAM and system, and the TT contents are hardly
renewed.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
drivers/gpu/drm/nouveau/nouveau_bo.c