From 2377427cdd2b7514eb4c40241cf5c4dec63c1bec Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 2 Jul 2020 09:32:03 +0100 Subject: [PATCH] drm/i915: Drop vm.ref for duplicate vma on construction As we allow for parallel threads to create the same vma instance concurrently, and we only filter out the duplicates upon reacquiring the spinlock for the rbtree, we have to free the loser of the constructors' race. When freeing, we should also drop any resource references acquired for the redundant vma. Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: # v5.5+ Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20200702083225.20044-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_vma.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index 1f63c4a1f055..7fe1f317cd2b 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -198,6 +198,7 @@ vma_create(struct drm_i915_gem_object *obj, cmp = i915_vma_compare(pos, vm, view); if (cmp == 0) { spin_unlock(&obj->vma.lock); + i915_vm_put(vm); i915_vma_free(vma); return pos; }