Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close v2
[AMD Official Use Only - Internal Distribution Only] yes, adding excl fence again as shared one is more reliable From: Christian König Sent: Wednesday, March 18, 2020 4:03:14 PM To: Pan, Xinhui Cc: amd-gfx@lists.freedesktop.org ; Liu, Monk Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close v2 The key point is that 10ms should be sufficient that either the move or the update is finished. One alternative which came to my mind would be to add the exclusive fence as shared as well in this case. This way we won't need to block at all. Christian. Am 18.03.20 um 09:00 schrieb Pan, Xinhui: > I wonder if it really fix anything with such small delay. but it should be no > harm anyway. > > Reviewed-by: xinhui pan > >> 2020年3月18日 15:51,Christian König 写道: >> >> Ping? Xinhui can I get an rb for this? >> >> Thanks, >> Christian. >> >> Am 16.03.20 um 14:22 schrieb Christian König: >>> The problem is that we can't add the clear fence to the BO >>> when there is an exclusive fence on it since we can't >>> guarantee the the clear fence will complete after the >>> exclusive one. >>> >>> To fix this refactor the function and wait for any potential >>> exclusive fence with a small timeout before adding the >>> shared clear fence. >>> >>> v2: fix warning >>> >>> Signed-off-by: Christian König >>> --- >>> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 43 +++-- >>> 1 file changed, 26 insertions(+), 17 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >>> index 5bec66e6b1f8..49c91dac35a0 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >>> @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object >>> *obj, >>> struct amdgpu_bo_list_entry vm_pd; >>> struct list_head list, duplicates; >>> + struct dma_fence *fence = NULL; >>> struct ttm_validate_buffer tv; >>> struct ww_acquire_ctx ticket; >>> struct amdgpu_bo_va *bo_va; >>> - int r; >>> + long r; >>> INIT_LIST_HEAD(); >>> INIT_LIST_HEAD(); >>> @@ -178,28 +179,36 @@ void amdgpu_gem_object_close(struct drm_gem_object >>> *obj, >>> r = ttm_eu_reserve_buffers(, , false, ); >>> if (r) { >>> dev_err(adev->dev, "leaking bo va because " >>> - "we fail to reserve bo (%d)\n", r); >>> + "we fail to reserve bo (%ld)\n", r); >>> return; >>> } >>> bo_va = amdgpu_vm_bo_find(vm, bo); >>> - if (bo_va && --bo_va->ref_count == 0) { >>> - amdgpu_vm_bo_rmv(adev, bo_va); >>> + if (!bo_va || --bo_va->ref_count) >>> + goto out_unlock; >>> - if (amdgpu_vm_ready(vm)) { >>> - struct dma_fence *fence = NULL; >>> + amdgpu_vm_bo_rmv(adev, bo_va); >>> + if (!amdgpu_vm_ready(vm)) >>> + goto out_unlock; >>> - r = amdgpu_vm_clear_freed(adev, vm, ); >>> - if (unlikely(r)) { >>> - dev_err(adev->dev, "failed to clear page " >>> - "tables on GEM object close (%d)\n", r); >>> - } >>> - if (fence) { >>> - amdgpu_bo_fence(bo, fence, true); >>> - dma_fence_put(fence); >>> - } >>> - } >>> - } >>> + r = amdgpu_vm_clear_freed(adev, vm, ); >>> + if (r || !fence) >>> + goto out_unlock; >>> + >>> + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, >>> + msecs_to_jiffies(10)); >>> + if (r == 0) >>> + r = -ETIMEDOUT; >>> + if (r) >>> + goto out_unlock; >>> + >>> + amdgpu_bo_fence(bo, fence, true); >>> + dma_fence_put(fence); >>> + >>> +out_unlock: >>> + if (unlikely(r < 0)) >>> + dev_err(adev->dev, "failed to clear page " >>> + "tables on GEM object close (%ld)\n", r); >>> ttm_eu_backoff_reservation(, ); >>> } >>> ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close v2
The key point is that 10ms should be sufficient that either the move or the update is finished. One alternative which came to my mind would be to add the exclusive fence as shared as well in this case. This way we won't need to block at all. Christian. Am 18.03.20 um 09:00 schrieb Pan, Xinhui: I wonder if it really fix anything with such small delay. but it should be no harm anyway. Reviewed-by: xinhui pan 2020年3月18日 15:51,Christian König 写道: Ping? Xinhui can I get an rb for this? Thanks, Christian. Am 16.03.20 um 14:22 schrieb Christian König: The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. v2: fix warning Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 43 +++-- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 5bec66e6b1f8..49c91dac35a0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -178,28 +179,36 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, r = ttm_eu_reserve_buffers(, , false, ); if (r) { dev_err(adev->dev, "leaking bo va because " - "we fail to reserve bo (%d)\n", r); + "we fail to reserve bo (%ld)\n", r); return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, true); - dma_fence_put(fence); - } - } - } + r = amdgpu_vm_clear_freed(adev, vm, ); + if (r || !fence) + goto out_unlock; + + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, + msecs_to_jiffies(10)); + if (r == 0) + r = -ETIMEDOUT; + if (r) + goto out_unlock; + + amdgpu_bo_fence(bo, fence, true); + dma_fence_put(fence); + +out_unlock: + if (unlikely(r < 0)) + dev_err(adev->dev, "failed to clear page " + "tables on GEM object close (%ld)\n", r); ttm_eu_backoff_reservation(, ); } ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close v2
I wonder if it really fix anything with such small delay. but it should be no harm anyway. Reviewed-by: xinhui pan > 2020年3月18日 15:51,Christian König 写道: > > Ping? Xinhui can I get an rb for this? > > Thanks, > Christian. > > Am 16.03.20 um 14:22 schrieb Christian König: >> The problem is that we can't add the clear fence to the BO >> when there is an exclusive fence on it since we can't >> guarantee the the clear fence will complete after the >> exclusive one. >> >> To fix this refactor the function and wait for any potential >> exclusive fence with a small timeout before adding the >> shared clear fence. >> >> v2: fix warning >> >> Signed-off-by: Christian König >> --- >> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 43 +++-- >> 1 file changed, 26 insertions(+), 17 deletions(-) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> index 5bec66e6b1f8..49c91dac35a0 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object >> *obj, >> struct amdgpu_bo_list_entry vm_pd; >> struct list_head list, duplicates; >> +struct dma_fence *fence = NULL; >> struct ttm_validate_buffer tv; >> struct ww_acquire_ctx ticket; >> struct amdgpu_bo_va *bo_va; >> -int r; >> +long r; >> INIT_LIST_HEAD(); >> INIT_LIST_HEAD(); >> @@ -178,28 +179,36 @@ void amdgpu_gem_object_close(struct drm_gem_object >> *obj, >> r = ttm_eu_reserve_buffers(, , false, ); >> if (r) { >> dev_err(adev->dev, "leaking bo va because " >> -"we fail to reserve bo (%d)\n", r); >> +"we fail to reserve bo (%ld)\n", r); >> return; >> } >> bo_va = amdgpu_vm_bo_find(vm, bo); >> -if (bo_va && --bo_va->ref_count == 0) { >> -amdgpu_vm_bo_rmv(adev, bo_va); >> +if (!bo_va || --bo_va->ref_count) >> +goto out_unlock; >> - if (amdgpu_vm_ready(vm)) { >> -struct dma_fence *fence = NULL; >> +amdgpu_vm_bo_rmv(adev, bo_va); >> +if (!amdgpu_vm_ready(vm)) >> +goto out_unlock; >> - r = amdgpu_vm_clear_freed(adev, vm, ); >> -if (unlikely(r)) { >> -dev_err(adev->dev, "failed to clear page " >> -"tables on GEM object close (%d)\n", r); >> -} >> - if (fence) { >> -amdgpu_bo_fence(bo, fence, true); >> -dma_fence_put(fence); >> -} >> -} >> -} >> +r = amdgpu_vm_clear_freed(adev, vm, ); >> +if (r || !fence) >> +goto out_unlock; >> + >> +r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, >> + msecs_to_jiffies(10)); >> +if (r == 0) >> +r = -ETIMEDOUT; >> +if (r) >> +goto out_unlock; >> + >> +amdgpu_bo_fence(bo, fence, true); >> +dma_fence_put(fence); >> + >> +out_unlock: >> +if (unlikely(r < 0)) >> +dev_err(adev->dev, "failed to clear page " >> +"tables on GEM object close (%ld)\n", r); >> ttm_eu_backoff_reservation(, ); >> } >> > ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close v2
Ping? Xinhui can I get an rb for this? Thanks, Christian. Am 16.03.20 um 14:22 schrieb Christian König: The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. v2: fix warning Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 43 +++-- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 5bec66e6b1f8..49c91dac35a0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -178,28 +179,36 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, r = ttm_eu_reserve_buffers(, , false, ); if (r) { dev_err(adev->dev, "leaking bo va because " - "we fail to reserve bo (%d)\n", r); + "we fail to reserve bo (%ld)\n", r); return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, true); - dma_fence_put(fence); - } - } - } + r = amdgpu_vm_clear_freed(adev, vm, ); + if (r || !fence) + goto out_unlock; + + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, + msecs_to_jiffies(10)); + if (r == 0) + r = -ETIMEDOUT; + if (r) + goto out_unlock; + + amdgpu_bo_fence(bo, fence, true); + dma_fence_put(fence); + +out_unlock: + if (unlikely(r < 0)) + dev_err(adev->dev, "failed to clear page " + "tables on GEM object close (%ld)\n", r); ttm_eu_backoff_reservation(, ); } ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
Am 12.03.20 um 16:03 schrieb Liu, Monk: The problem is that dma_resv_test_signaled_rcu() tests only the shared fence if one is present. Okay I got the point now, but why we cannot modify dma_resv_test_signaled_rcu() to let it wait for both exclusive and shared lists ? That is exactly what I and Xinhui said as well and what we also both proposed in patches, but the Intel guys are against that. I also already proposed an extension to the dma_resv infrastructure where you get a list of "other" fences for stuff like this, but it wasn't to well received either and I can't dedicate more time to this. Regards, Christian. Ack-by: Monk Liu _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Koenig, Christian Sent: Thursday, March 12, 2020 9:42 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that dma_resv_test_signaled_rcu() tests only the shared fence if one is present. Now what happened is that the clear fence completed before the exclusive one, and that in turn caused TTM to think that the BO is unused and freed it. Christian. Am 12.03.20 um 14:25 schrieb Liu, Monk: without your patch, the clear fence is also hooked in the shared list of bo's reservation obj, no matter the exclusive fence of that BO signaled before clear fence or not since the clear fence is always kept in the bo's resv object, can you tell me what's the problem than ? are we going to loose this clear fence and still use it during the VM pt/pd clearing ? thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Christian König Sent: Thursday, March 12, 2020 8:50 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close From the semantic the dma_resv object contains a single exclusive and multiple shared fences and it is mandatory that the shared fences complete after the exclusive one. Now what happens is that clearing the VM page tables runs asynchronously to the exclusive fence which moves the buffer around. And because of this Xinhui ran into a rare problem that TTM thought it could reuse the memory while in reality it was still in use. Regards, Christian. Am 12.03.20 um 12:30 schrieb Liu, Monk: Can you give more details about " we can't guarantee the the clear fence will complete after the exclusive one." ? Thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: amd-gfx On Behalf Of Christian K?nig Sent: Thursday, March 12, 2020 7:12 PM To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 4277125a79ee..0782162fb5f3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, t
RE: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
>>> The problem is that dma_resv_test_signaled_rcu() tests only the shared >>> fence if one is present. Okay I got the point now, but why we cannot modify dma_resv_test_signaled_rcu() to let it wait for both exclusive and shared lists ? Ack-by: Monk Liu _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Koenig, Christian Sent: Thursday, March 12, 2020 9:42 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that dma_resv_test_signaled_rcu() tests only the shared fence if one is present. Now what happened is that the clear fence completed before the exclusive one, and that in turn caused TTM to think that the BO is unused and freed it. Christian. Am 12.03.20 um 14:25 schrieb Liu, Monk: > without your patch, the clear fence is also hooked in the shared list > of bo's reservation obj, no matter the exclusive fence of that BO > signaled before clear fence or not > > since the clear fence is always kept in the bo's resv object, can you tell me > what's the problem than ? are we going to loose this clear fence and still > use it during the VM pt/pd clearing ? > > thanks > _ > Monk Liu|GPU Virtualization Team |AMD > > > -Original Message- > From: Christian König > Sent: Thursday, March 12, 2020 8:50 PM > To: Liu, Monk ; Pan, Xinhui ; > amd-gfx@lists.freedesktop.org > Subject: Re: [PATCH] drm/amdgpu: fix and cleanup > amdgpu_gem_object_close > > From the semantic the dma_resv object contains a single exclusive and > multiple shared fences and it is mandatory that the shared fences complete > after the exclusive one. > > Now what happens is that clearing the VM page tables runs asynchronously to > the exclusive fence which moves the buffer around. > > And because of this Xinhui ran into a rare problem that TTM thought it could > reuse the memory while in reality it was still in use. > > Regards, > Christian. > > Am 12.03.20 um 12:30 schrieb Liu, Monk: >> Can you give more details about " we can't guarantee the the clear fence >> will complete after the exclusive one." ? >> >> Thanks >> >> _ >> Monk Liu|GPU Virtualization Team |AMD >> >> >> -Original Message- >> From: amd-gfx On Behalf Of >> Christian K?nig >> Sent: Thursday, March 12, 2020 7:12 PM >> To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org >> Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close >> >> The problem is that we can't add the clear fence to the BO when there is an >> exclusive fence on it since we can't guarantee the the clear fence will >> complete after the exclusive one. >> >> To fix this refactor the function and wait for any potential exclusive fence >> with a small timeout before adding the shared clear fence. >> >> Signed-off-by: Christian König >> --- >>drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- >>1 file changed, 25 insertions(+), 16 deletions(-) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> index 4277125a79ee..0782162fb5f3 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c >> @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct >> drm_gem_object *obj, >> >> struct amdgpu_bo_list_entry vm_pd; >> struct list_head list, duplicates; >> +struct dma_fence *fence = NULL; >> struct ttm_validate_buffer tv; >> struct ww_acquire_ctx ticket; >> struct amdgpu_bo_va *bo_va; >> -int r; >> +long r; >> >> INIT_LIST_HEAD(); >> INIT_LIST_HEAD(); >> @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object >> *obj, >> return; >> } >> bo_va = amdgpu_vm_bo_find(vm, bo); >> -if (bo_va && --bo_va->ref_count == 0) { >> -amdgpu_vm_bo_rmv(adev, bo_va); >> +if (!bo_va || --bo_va->ref_count) >> +goto out_unlock; >> >> -if (amdgpu_vm_ready(vm)) { >> -struct dma_fence *fence = NULL; >> +amdgpu_vm_bo_rmv(adev, bo_va); >> +if (!amdgpu_vm_ready(vm)) >> +goto out_unlock; >> >> -r = amdgpu_vm_clear_freed(adev, vm, ); >> -if (unlikely(r)) { >> -
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
The problem is that dma_resv_test_signaled_rcu() tests only the shared fence if one is present. Now what happened is that the clear fence completed before the exclusive one, and that in turn caused TTM to think that the BO is unused and freed it. Christian. Am 12.03.20 um 14:25 schrieb Liu, Monk: without your patch, the clear fence is also hooked in the shared list of bo's reservation obj, no matter the exclusive fence of that BO signaled before clear fence or not since the clear fence is always kept in the bo's resv object, can you tell me what's the problem than ? are we going to loose this clear fence and still use it during the VM pt/pd clearing ? thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Christian König Sent: Thursday, March 12, 2020 8:50 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close From the semantic the dma_resv object contains a single exclusive and multiple shared fences and it is mandatory that the shared fences complete after the exclusive one. Now what happens is that clearing the VM page tables runs asynchronously to the exclusive fence which moves the buffer around. And because of this Xinhui ran into a rare problem that TTM thought it could reuse the memory while in reality it was still in use. Regards, Christian. Am 12.03.20 um 12:30 schrieb Liu, Monk: Can you give more details about " we can't guarantee the the clear fence will complete after the exclusive one." ? Thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: amd-gfx On Behalf Of Christian K?nig Sent: Thursday, March 12, 2020 7:12 PM To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 4277125a79ee..0782162fb5f3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, true); - dma_fence_put(fence); - } - } - } + r = amdgpu_vm_clear_freed(adev, vm, ); + if (r || !fence) + goto out_unlock; + + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, + msecs_to_jiffies(10)); + if (r == 0) + r = -ETIMEDOUT; + if (r) + goto out_unlock; + + amdgpu_bo_fence(bo, fence, true); + dma_fence_put(fence); + +out_unlock: + if (unlikely(r)) + dev_err(adev->dev, "failed to clear page " + "tables on GEM object close (%d)\n", r); ttm_eu_backoff_reservation(, ); } -- 2.17.1 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist s.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfxdata=02%7C01%7CMo nk.Liu%40amd.com%7C267
RE: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
>> Now what happens is that clearing the VM page tables runs asynchronously to >> the exclusive fence which moves the buffer around. The amdgpu_vm_clear_freed is already kicked off before you wait for the exclusive fence signaled, why you can avoid clearing PT not overlap with the "move" action after you introduce a " dma_resv_wait_timeout_rcu" *after* the amdgpu_vm_clear_freed () ? _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Christian König Sent: Thursday, March 12, 2020 8:50 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close From the semantic the dma_resv object contains a single exclusive and multiple shared fences and it is mandatory that the shared fences complete after the exclusive one. Now what happens is that clearing the VM page tables runs asynchronously to the exclusive fence which moves the buffer around. And because of this Xinhui ran into a rare problem that TTM thought it could reuse the memory while in reality it was still in use. Regards, Christian. Am 12.03.20 um 12:30 schrieb Liu, Monk: > Can you give more details about " we can't guarantee the the clear fence will > complete after the exclusive one." ? > > Thanks > > _ > Monk Liu|GPU Virtualization Team |AMD > > > -Original Message- > From: amd-gfx On Behalf Of > Christian K?nig > Sent: Thursday, March 12, 2020 7:12 PM > To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org > Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close > > The problem is that we can't add the clear fence to the BO when there is an > exclusive fence on it since we can't guarantee the the clear fence will > complete after the exclusive one. > > To fix this refactor the function and wait for any potential exclusive fence > with a small timeout before adding the shared clear fence. > > Signed-off-by: Christian König > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- > 1 file changed, 25 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > index 4277125a79ee..0782162fb5f3 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct > drm_gem_object *obj, > > struct amdgpu_bo_list_entry vm_pd; > struct list_head list, duplicates; > + struct dma_fence *fence = NULL; > struct ttm_validate_buffer tv; > struct ww_acquire_ctx ticket; > struct amdgpu_bo_va *bo_va; > - int r; > + long r; > > INIT_LIST_HEAD(); > INIT_LIST_HEAD(); > @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, > return; > } > bo_va = amdgpu_vm_bo_find(vm, bo); > - if (bo_va && --bo_va->ref_count == 0) { > - amdgpu_vm_bo_rmv(adev, bo_va); > + if (!bo_va || --bo_va->ref_count) > + goto out_unlock; > > - if (amdgpu_vm_ready(vm)) { > - struct dma_fence *fence = NULL; > + amdgpu_vm_bo_rmv(adev, bo_va); > + if (!amdgpu_vm_ready(vm)) > + goto out_unlock; > > - r = amdgpu_vm_clear_freed(adev, vm, ); > - if (unlikely(r)) { > - dev_err(adev->dev, "failed to clear page " > - "tables on GEM object close (%d)\n", r); > - } > > - if (fence) { > - amdgpu_bo_fence(bo, fence, true); > - dma_fence_put(fence); > - } > - } > - } > + r = amdgpu_vm_clear_freed(adev, vm, ); > + if (r || !fence) > + goto out_unlock; > + > + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, > + msecs_to_jiffies(10)); > + if (r == 0) > + r = -ETIMEDOUT; > + if (r) > + goto out_unlock; > + > + amdgpu_bo_fence(bo, fence, true); > + dma_fence_put(fence); > + > +out_unlock: > + if (unlikely(r)) > + dev_err(adev->dev, "failed to clear page " > + "tables on GEM object close (%d)\n", r); > ttm_eu_backoff_reservation(, ); } > > -- > 2.17.1 > > ___ > amd-gfx mailing list > amd-gfx@
RE: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
without your patch, the clear fence is also hooked in the shared list of bo's reservation obj, no matter the exclusive fence of that BO signaled before clear fence or not since the clear fence is always kept in the bo's resv object, can you tell me what's the problem than ? are we going to loose this clear fence and still use it during the VM pt/pd clearing ? thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: Christian König Sent: Thursday, March 12, 2020 8:50 PM To: Liu, Monk ; Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close From the semantic the dma_resv object contains a single exclusive and multiple shared fences and it is mandatory that the shared fences complete after the exclusive one. Now what happens is that clearing the VM page tables runs asynchronously to the exclusive fence which moves the buffer around. And because of this Xinhui ran into a rare problem that TTM thought it could reuse the memory while in reality it was still in use. Regards, Christian. Am 12.03.20 um 12:30 schrieb Liu, Monk: > Can you give more details about " we can't guarantee the the clear fence will > complete after the exclusive one." ? > > Thanks > > _ > Monk Liu|GPU Virtualization Team |AMD > > > -Original Message- > From: amd-gfx On Behalf Of > Christian K?nig > Sent: Thursday, March 12, 2020 7:12 PM > To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org > Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close > > The problem is that we can't add the clear fence to the BO when there is an > exclusive fence on it since we can't guarantee the the clear fence will > complete after the exclusive one. > > To fix this refactor the function and wait for any potential exclusive fence > with a small timeout before adding the shared clear fence. > > Signed-off-by: Christian König > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- > 1 file changed, 25 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > index 4277125a79ee..0782162fb5f3 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct > drm_gem_object *obj, > > struct amdgpu_bo_list_entry vm_pd; > struct list_head list, duplicates; > + struct dma_fence *fence = NULL; > struct ttm_validate_buffer tv; > struct ww_acquire_ctx ticket; > struct amdgpu_bo_va *bo_va; > - int r; > + long r; > > INIT_LIST_HEAD(); > INIT_LIST_HEAD(); > @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, > return; > } > bo_va = amdgpu_vm_bo_find(vm, bo); > - if (bo_va && --bo_va->ref_count == 0) { > - amdgpu_vm_bo_rmv(adev, bo_va); > + if (!bo_va || --bo_va->ref_count) > + goto out_unlock; > > - if (amdgpu_vm_ready(vm)) { > - struct dma_fence *fence = NULL; > + amdgpu_vm_bo_rmv(adev, bo_va); > + if (!amdgpu_vm_ready(vm)) > + goto out_unlock; > > - r = amdgpu_vm_clear_freed(adev, vm, ); > - if (unlikely(r)) { > - dev_err(adev->dev, "failed to clear page " > - "tables on GEM object close (%d)\n", r); > - } > > - if (fence) { > - amdgpu_bo_fence(bo, fence, true); > - dma_fence_put(fence); > - } > - } > - } > + r = amdgpu_vm_clear_freed(adev, vm, ); > + if (r || !fence) > + goto out_unlock; > + > + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, > + msecs_to_jiffies(10)); > + if (r == 0) > + r = -ETIMEDOUT; > + if (r) > + goto out_unlock; > + > + amdgpu_bo_fence(bo, fence, true); > + dma_fence_put(fence); > + > +out_unlock: > + if (unlikely(r)) > + dev_err(adev->dev, "failed to clear page " > + "tables on GEM object close (%d)\n", r); > ttm_eu_backoff_reservation(, ); } > > -- > 2.17.1 > > ___ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://nam11.safe
Re: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
From the semantic the dma_resv object contains a single exclusive and multiple shared fences and it is mandatory that the shared fences complete after the exclusive one. Now what happens is that clearing the VM page tables runs asynchronously to the exclusive fence which moves the buffer around. And because of this Xinhui ran into a rare problem that TTM thought it could reuse the memory while in reality it was still in use. Regards, Christian. Am 12.03.20 um 12:30 schrieb Liu, Monk: Can you give more details about " we can't guarantee the the clear fence will complete after the exclusive one." ? Thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: amd-gfx On Behalf Of Christian K?nig Sent: Thursday, March 12, 2020 7:12 PM To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 4277125a79ee..0782162fb5f3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, true); - dma_fence_put(fence); - } - } - } + r = amdgpu_vm_clear_freed(adev, vm, ); + if (r || !fence) + goto out_unlock; + + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, + msecs_to_jiffies(10)); + if (r == 0) + r = -ETIMEDOUT; + if (r) + goto out_unlock; + + amdgpu_bo_fence(bo, fence, true); + dma_fence_put(fence); + +out_unlock: + if (unlikely(r)) + dev_err(adev->dev, "failed to clear page " + "tables on GEM object close (%d)\n", r); ttm_eu_backoff_reservation(, ); } -- 2.17.1 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfxdata=02%7C01%7Cmonk.liu%40amd.com%7C3826cd029c9a4d00617008d7c6763433%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637196083320910768sdata=1jCINJLzbYhXx9at5%2FU%2FX6d6476FhbhUYZrs53ARSAY%3Dreserved=0 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
RE: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close
Can you give more details about " we can't guarantee the the clear fence will complete after the exclusive one." ? Thanks _ Monk Liu|GPU Virtualization Team |AMD -Original Message- From: amd-gfx On Behalf Of Christian K?nig Sent: Thursday, March 12, 2020 7:12 PM To: Pan, Xinhui ; amd-gfx@lists.freedesktop.org Subject: [PATCH] drm/amdgpu: fix and cleanup amdgpu_gem_object_close The problem is that we can't add the clear fence to the BO when there is an exclusive fence on it since we can't guarantee the the clear fence will complete after the exclusive one. To fix this refactor the function and wait for any potential exclusive fence with a small timeout before adding the shared clear fence. Signed-off-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 41 +++-- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 4277125a79ee..0782162fb5f3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -161,10 +161,11 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, struct amdgpu_bo_list_entry vm_pd; struct list_head list, duplicates; + struct dma_fence *fence = NULL; struct ttm_validate_buffer tv; struct ww_acquire_ctx ticket; struct amdgpu_bo_va *bo_va; - int r; + long r; INIT_LIST_HEAD(); INIT_LIST_HEAD(); @@ -182,24 +183,32 @@ void amdgpu_gem_object_close(struct drm_gem_object *obj, return; } bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo_va && --bo_va->ref_count == 0) { - amdgpu_vm_bo_rmv(adev, bo_va); + if (!bo_va || --bo_va->ref_count) + goto out_unlock; - if (amdgpu_vm_ready(vm)) { - struct dma_fence *fence = NULL; + amdgpu_vm_bo_rmv(adev, bo_va); + if (!amdgpu_vm_ready(vm)) + goto out_unlock; - r = amdgpu_vm_clear_freed(adev, vm, ); - if (unlikely(r)) { - dev_err(adev->dev, "failed to clear page " - "tables on GEM object close (%d)\n", r); - } - if (fence) { - amdgpu_bo_fence(bo, fence, true); - dma_fence_put(fence); - } - } - } + r = amdgpu_vm_clear_freed(adev, vm, ); + if (r || !fence) + goto out_unlock; + + r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false, + msecs_to_jiffies(10)); + if (r == 0) + r = -ETIMEDOUT; + if (r) + goto out_unlock; + + amdgpu_bo_fence(bo, fence, true); + dma_fence_put(fence); + +out_unlock: + if (unlikely(r)) + dev_err(adev->dev, "failed to clear page " + "tables on GEM object close (%d)\n", r); ttm_eu_backoff_reservation(, ); } -- 2.17.1 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfxdata=02%7C01%7Cmonk.liu%40amd.com%7C3826cd029c9a4d00617008d7c6763433%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637196083320910768sdata=1jCINJLzbYhXx9at5%2FU%2FX6d6476FhbhUYZrs53ARSAY%3Dreserved=0 ___ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx