From 74af1e2c16749514fc8db4fc97e59ce897b73fc9 Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Fri, 24 Sep 2021 18:38:25 +0200 Subject: [PATCH] drm/i915: Flush buffer pools on driver remove We currently do an explicit flush of the buffer pools within the call path of drm_driver.release(); this removes all buffers, regardless of their age, freeing the buffers' associated resources (objects, address space areas). However there is other code that runs within the drm_driver.release() call chain that expects objects and their associated address space areas have already been flushed. Since buffer pools auto-flush old buffers once per second in a worker thread, there's a small window where if we remove the driver while there are still objects in buffers with an age of less than one second, the assumptions of the other release code may be violated. By moving the flush to driver remove (which executes earlier via the pci_driver.remove() flow) we're ensuring that all buffers are flushed and their associated objects freed before some other code in pci_driver.remove() flushes those objects so they are released before _any_ code in drm_driver.release() that check completness of those flushes executes. v2: Reword commit description as suggested by Matt. Signed-off-by: Janusz Krzysztofik Cc: Chris Wilson Cc: Matt Roper Signed-off-by: Matt Roper Reviewed-by: Matt Roper Link: https://patchwork.freedesktop.org/patch/msgid/20210924163825.634606-1-janusz.krzysztofik@linux.intel.com --- drivers/gpu/drm/i915/gt/intel_gt.c | 2 ++ drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index 4037c37782253..5b3acf2b064e3 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -741,6 +741,8 @@ void intel_gt_driver_remove(struct intel_gt *gt) intel_uc_driver_remove(>->uc); intel_engines_release(gt); + + intel_gt_flush_buffer_pool(gt); } void intel_gt_driver_unregister(struct intel_gt *gt) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c index aa0a59c5b6147..acc49c56a9f30 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c @@ -245,8 +245,6 @@ void intel_gt_fini_buffer_pool(struct intel_gt *gt) struct intel_gt_buffer_pool *pool = >->buffer_pool; int n; - intel_gt_flush_buffer_pool(gt); - for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) GEM_BUG_ON(!list_empty(&pool->cache_list[n])); } -- 2.30.2