On 04/01/2022 12:51, Thomas Hellström wrote:
Implement async (non-blocking) unbinding by not syncing the vma before calling unbind on the vma_resource. Add the resulting unbind fence to the object's dma_resv from where it is picked up by the ttm migration code. Ideally these unbind fences should be coalesced with the migration blit fence to avoid stalling the migration blit waiting for unbind, as they can certainly go on in parallel, but since we don't yet have a reasonable data structure to use to coalesce fences and attach the resulting fence to a timeline, we defer that for now.
Note that with async unbinding, even while the unbind waits for the preceding bind to complete before unbinding, the vma itself might have been destroyed in the process, clearing the vma pages. Therefore we can only allow async unbinding if we have a refcounted sg-list and keep a refcount on that for the vma resource pages to stay intact until binding occurs. If this condition is not met, a request for an async unbind is diverted to a sync unbind.
v2:
- Use a separate kmem_cache for vma resources for now to isolate their memory allocation and aid debugging.
- Move the check for vm closed to the actual unbinding thread. Regardless of whether the vm is closed, we need the unbind fence to properly wait for capture.
- Clear vma_res::vm on unbind and update its documentation.
v4:
- Take cache coloring into account when searching for vma resources pending unbind. (Matthew Auld)
v5:
- Fix timeout and error check in i915_vma_resource_bind_dep_await().
- Avoid taking a reference on the object for async binding if async unbind capable.
- Fix braces around a single-line if statement.
Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com
<snip>
+static void +i915_vma_resource_color_adjust_range(struct i915_address_space *vm,
unsigned long *start,unsigned long *end)
Make these u64, below also? Just in case this is 32b?
+{
- if (i915_vm_has_cache_coloring(vm)) {
if (start)start -= I915_GTT_PAGE_SIZE;end += I915_GTT_PAGE_SIZE;
*start *end :)
- }
else { WARN_ON_ONCE(vm->color_adjust); }
?
+}