Makes sense, Reviewed-by: Christian König <christian.koenig at amd.com> fro this one as well. Regards, Christian. Am 14.11.2017 um 16:00 schrieb Liu, Monk: > Actually " drm_mm_takedown" below will give you the warning if some BO is still in MM > That means below part is totally useless: > >>> - spin_lock(&mgr->lock); >>> - if (!drm_mm_clean(&mgr->mm)) { >>> - spin_unlock(&mgr->lock); >>> - return -EBUSY; >>> - } >>> - > And the worse thing is this "return -EBUSY" would lead to memory leak because it blocks following kfree() on mgr... > BR Monk > > -----Original Message----- > From: Christian König [mailto:ckoenig.leichtzumerken at gmail.com] > Sent: 2017å¹´11æ??14æ?¥ 20:01 > To: Liu, Monk <Monk.Liu at amd.com>; amd-gfx at lists.freedesktop.org > Subject: Re: [PATCH 05/10] drm/amdgpu:fix memleak in takedown > > Am 14.11.2017 um 12:52 schrieb Christian König: >> Am 14.11.2017 um 10:07 schrieb Monk Liu: >>> this can fix the memory leak under the case that not all BO are freed >>> during "takedown" stage, because originally it blocks following kfree >>> on mgr. >> NAK, all BOs must be freed before we take down at least the GTT manager. > Ah, wait a second. That is the address space manager here! > > Mhm, returning -EBUSY is probably not a good idea, but we should at least print some warning. > > Regards, > Christian. > >> That we run into a memory leak is intended, cause that is still better >> than crashing the system because we access already freed up memory. >> >> Regards, >> Christian. >> >>> Change-Id: I56e832ac317215a4d9f58edb8e75ea722158715c >>> Signed-off-by: Monk Liu <Monk.Liu at amd.com> >>> --- >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 6 ------ >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 5 ----- >>>  2 files changed, 11 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c >>> index 88709f9..72819cc 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c >>> @@ -76,12 +76,6 @@ static int amdgpu_gtt_mgr_fini(struct >>> ttm_mem_type_manager *man) >>>  { >>>      struct amdgpu_gtt_mgr *mgr = man->priv; >>>  -   spin_lock(&mgr->lock); >>> -   if (!drm_mm_clean(&mgr->mm)) { >>> -       spin_unlock(&mgr->lock); >>> -       return -EBUSY; >>> -   } >>> - >>>      drm_mm_takedown(&mgr->mm); >>>      spin_unlock(&mgr->lock); >>>      kfree(mgr); >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> index 4ca622b..3e883e5 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c >>> @@ -68,11 +68,6 @@ static int amdgpu_vram_mgr_fini(struct >>> ttm_mem_type_manager *man) >>>      struct amdgpu_vram_mgr *mgr = man->priv; >>>       spin_lock(&mgr->lock); >>> -   if (!drm_mm_clean(&mgr->mm)) { >>> -       spin_unlock(&mgr->lock); >>> -       return -EBUSY; >>> -   } >>> - >>>      drm_mm_takedown(&mgr->mm); >>>      spin_unlock(&mgr->lock); >>>      kfree(mgr); >>