On 08/12/15 17:00, Chris Wilson wrote:
On Tue, Dec 08, 2015 at 04:51:17PM +0000, Dave Gordon wrote:
In various places, one or more pages of a GEM object are mapped into CPU
address space and updated. In each such case, either the page or the the
object should be marked dirty, to ensure that the modifications are not
discarded if the object is evicted under memory pressure.
Ideally, we would like to mark only the updated pages dirty; but it
isn't clear at this point whether this will work for all types of GEM
objects (regular/gtt, phys, stolen, userptr, dmabuf, ...). So for now,
let's ensure correctness by marking the whole object dirty.
Signed-off-by: Dave Gordon <david.s.gordon@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 ++
drivers/gpu/drm/i915/i915_gem_render_state.c | 1 +
drivers/gpu/drm/i915/i915_guc_submission.c | 1 +
drivers/gpu/drm/i915/intel_lrc.c | 6 +++++-
4 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index a4c243c..bc28a10 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -281,6 +281,7 @@ relocate_entry_cpu(struct drm_i915_gem_object *obj,
}
kunmap_atomic(vaddr);
+ obj->dirty = 1;
Nak. CPU dirtying is a per-page interface.
-Chris
That's what my commit message said. But let's at least have /correct/
behaviour while we work out which object types we (can) support here.
Also, in:
if (use_cpu_reloc(obj))
ret = relocate_entry_cpu(obj, reloc, target_offset);
else if (obj->map_and_fenceable)
ret = relocate_entry_gtt(obj, reloc, target_offset);
else if (cpu_has_clflush)
ret = relocate_entry_clflush(obj, reloc, target_offset);
both the other routines parallel to relocate_entry_cpu() [i.e.
relocate_entry_gtt() and relocate_entry_clflush()] mark the whole object
dirty. Why be inconsistent?
Can we be sure that the object in question actually has per-page
tracking of dirty pages. shmfs objects do, but not phys, which only has
object-level dirty tracking. Can we guarantee that only the right sort
of objects will be handled here? And when stolen objects are exposed to
the user?
.Dave.
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
