Hi,
On 1/18/23 10:19, Tvrtko Ursulin wrote:
Thanks for working on this, it looks good to me and it aligns with how i915 uses the facility.
Copying Mirsad who reported the issue in case he is still happy to give it a quick test. Mirsad, I don't know if you are subscribed
to one of the two mailing lists where series was posted. In case not, you can grab both patches from
https://patchwork.freedesktop.org/series/112952/.
Nirmoy - we also have an IGT written by Chuansheng - https://patchwork.freedesktop.org/patch/515720/?series=101035&rev=4. A more
generic one could be placed in gem_mmap_offset test but this one works too in my testing and is IMO better than nothing.
Finally, let me add some tags below:
On 17/01/2023 17:52, Nirmoy Das wrote:
drm_vma_node_allow() and drm_vma_node_revoke() should be called in
balanced pairs. We call drm_vma_node_allow() once per-file everytime a
user calls mmap_offset, but only call drm_vma_node_revoke once per-file
on each mmap_offset. As the mmap_offset is reused by the client, the
per-file vm_count may remain non-zero and the rbtree leaked.
Call drm_vma_node_allow_once() instead to prevent that memory leak.
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Fixes: 786555987207 ("drm/i915/gem: Store mmap_offsets in an rbtree rather than a plain list")
Reported-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx>
Reported-by: Mirsad Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v5.7+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Regards,
Tvrtko
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 4f69bff63068..2aac6bf78740 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -697,7 +697,7 @@ mmap_offset_attach(struct drm_i915_gem_object *obj,
GEM_BUG_ON(lookup_mmo(obj, mmap_type) != mmo);
out:
if (file)
- drm_vma_node_allow(&mmo->vma_node, file);
+ drm_vma_node_allow_once(&mmo->vma_node, file);
return mmo;
err:
The drm/i915 patch seems OK and there are currently no memory leaks as of
reported by /sys/kernel/debug/kmemleak under the same Chrome load that triggered
the initial bug ...
Will post you if there are any changes.
Regards,
Mirsad
--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
