Op 21-11-12 14:15, Maarten Lankhorst schreef:
With this fix, nouveau_gem_object_close can be safely changed to a noop, forcing the vm bindings to be removed when the original object is. This is not done in this patch since it may lead to the object staying mapped in the vm space until the gem object refcount drops to 0. This shouldn't be a big issue however.
If we choose to do so does allow us to use ttm's delayed destruction mechanism to unmap vm after object is idle, resulting in ioread32 no longer taking up 30% of cpu in Team Fortress 2 if I don't do the vma unmap in nouveau_gem_object_close.
And for those crazy enough to try, deliberately in the most hacky form possible:
drm/nouveau: use ttm delayed destroy for unmapping vm
According to perf top, drops ioread32 from taking 30% cpu to 3% cpu..
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c index 5e2f521..bdb99ab 100644 --- a/drivers/gpu/drm/nouveau/nouveau_gem.c +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c @@ -111,7 +111,7 @@ nouveau_gem_object_close(struct drm_gem_object *gem, struct drm_file *file_priv) struct nouveau_vma *vma; int ret;
- if (!cli->base.vm) +// if (!cli->base.vm) return;
ret = ttm_bo_reserve(&nvbo->bo, false, false, false, 0);