Blaster4385/linux-IllusionX
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

drm/xe/client: fix deadlock in show_meminfo()

Browse source 
There is a real deadlock as well as sleeping in atomic() bug in here, if
the bo put happens to be the last ref, since bo destruction wants to
grab the same spinlock and sleeping locks.  Fix that by dropping the ref
using xe_bo_put_deferred(), and moving the final commit outside of the
lock. Dropping the lock around the put is tricky since the bo can go
out of scope and delete itself from the list, making it difficult to
navigate to the next list entry.

Fixes: 0845233388 ("drm/xe: Implement fdinfo memory stats printing")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2727
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: <stable@vger.kernel.org> # v6.8+
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240911155527.178910-5-matthew.auld@intel.com
(cherry picked from commit 0083b8e6f11d7662283a267d4ce7c966812ffd8a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Matthew Auld 2024-09-11 16:55:27 +01:00 committed by Rodrigo Vivi
parent a262cc8d55
commit 9bd7ff293f
No known key found for this signature in database
GPG key ID: FA625F640EEB13CA
1 changed files with 5 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/gpu/drm/xe/xe_drm_client.c
View file

@ -196,6 +196,7 @@ static void show_meminfo(struct drm_printer *p, struct drm_file *file)
struct xe_drm_client *client;
struct drm_gem_object *obj;
struct xe_bo *bo;
LLIST_HEAD(deferred);
unsigned int id;
u32 mem_type;
@ -215,11 +216,14 @@ static void show_meminfo(struct drm_printer *p, struct drm_file *file)
list_for_each_entry(bo, &client->bos_list, client_link) {
if (!kref_get_unless_zero(&bo->ttm.base.refcount))
continue;
bo_meminfo(bo, stats);
xe_bo_put(bo);
xe_bo_put_deferred(bo, &deferred);
}
spin_unlock(&client->bos_lock);
xe_bo_put_commit(&deferred);
for (mem_type = XE_PL_SYSTEM; mem_type < TTM_NUM_MEM_TYPES; ++mem_type) {
if (!xe_mem_type_to_name[mem_type])
continue;