(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

drm/xe/vf: Fix fs_reclaim warning with CCS save/restore BB allocation

CCS save/restore batch buffers are attached during BO allocation and detached during BO teardown. The shrinker triggers xe_bo_move(), which is used for both allocation and deletion paths. When BO allocation and shrinking occur concurrently, a circular locking dependency involving fs_reclaim and swap_guard can occur, leading to a deadlock such as: *===============================================================* * WARNING: possible circular locking dependency detected * *---------------------------------------------------------------* * * * CPU0 CPU1 * * ---- ---- * * lock(fs_reclaim); * * lock(&sa_manager->swap_guard); * * lock(fs_reclaim); * * lock(&sa_manager->swap_guard); * * * * *** DEADLOCK *** * *===============================================================* To avoid this, the BB pointer and SA are allocated using xe_bb_alloc() before taking lock and SA is initialized using xe_bb_init() preventing reclaim from being invoked in this context. Fixes: 864690cf4dd62 ("drm/xe/vf: Attach and detach CCS copy commands with BO") Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Maarten Lankhorst <dev@lankhorst.se> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Signed-off-by: Matthew Brost <matthew.brost@intel.com> Link: https://patch.msgid.link/20260220055519.2485681-7-satyanarayana.k.v.p@intel.com


Author Satyanarayana K V P Committer Matthew Brost Date Commit Parent 16843e66
+132 -64
5 changed files
+132 -64
5 changed files