[PATCH v7 20/20] drm/i915/vm_bind: Async vm_unbind support
Matthew Auld
matthew.auld at intel.com
Wed Nov 23 11:42:58 UTC 2022
On 16/11/2022 00:37, Niranjana Vishwanathapura wrote:
> On Tue, Nov 15, 2022 at 03:15:03PM -0800, Niranjana Vishwanathapura wrote:
>> On Tue, Nov 15, 2022 at 08:33:47AM -0800, Niranjana Vishwanathapura
>> wrote:
>>> On Tue, Nov 15, 2022 at 04:20:54PM +0000, Matthew Auld wrote:
>>>> On 15/11/2022 16:15, Niranjana Vishwanathapura wrote:
>>>>> On Tue, Nov 15, 2022 at 11:05:21AM +0000, Matthew Auld wrote:
>>>>>> On 13/11/2022 07:57, Niranjana Vishwanathapura wrote:
>>>>>>> Asynchronously unbind the vma upon vm_unbind call.
>>>>>>> Fall back to synchronous unbind if backend doesn't support
>>>>>>> async unbind or if async unbind fails.
>>>>>>>
>>>>>>> No need for vm_unbind out fence support as i915 will internally
>>>>>>> handle all sequencing and user need not try to sequence any
>>>>>>> operation with the unbind completion.
>>>>>>>
>>>>>>> v2: use i915_vma_destroy_async in vm_unbind ioctl
>>>>>>>
>>>>>>> Signed-off-by: Niranjana Vishwanathapura
>>>>>>> <niranjana.vishwanathapura at intel.com>
>>>>>>
>>>>>> This only does it for non-partial vma, right? Or was that changed
>>>>>> somewhere?
>>>>>>
>>>>>
>>>>> No, it applies to any vma (partial or non-partial).
>>>>> It was so from the beginning.
>>>>
>>>> Doesn't __i915_vma_unbind_async() return an error when mm.pages !=
>>>> vma->pages? IIRC this was discussed before. Just trying to think
>>>> about the consequences of this change.
>>>
>>> I am not seeing any such restriction. Let me probe and check if there
>>> is any such restriction anywhere in the call chain.
>>
>> I checked and I am not seeing any restriction anywher in the call chain.
>>
>
> Note that just like binding case, unbinding is also synchronous unless
> there is a pending activity, in which case, it will be asynchronous.
In __i915_vma_unbind_async() there is:
if (i915_vma_is_pinned(vma) ||
&vma->obj->mm.rsgt->table != vma->resource->bi.pages)
return ERR_PTR(-EAGAIN);
AFAICT we then also don't get any pipelined moves with such an object,
if there is such a binding present.
>
> Niranjana
>
>> Niranjana
>>
>>>
>>> Niranjana
>>>
>>>>
>>>>>
>>>>> Niranjana
>>>>>
>>>>>> Reviewed-by: Matthew Auld <matthew.auld at intel.com>
>>>>>>
>>>>>>> ---
>>>>>>> .../drm/i915/gem/i915_gem_vm_bind_object.c | 2 +-
>>>>>>> drivers/gpu/drm/i915/i915_vma.c | 51
>>>>>>> +++++++++++++++++--
>>>>>>> drivers/gpu/drm/i915/i915_vma.h | 1 +
>>>>>>> include/uapi/drm/i915_drm.h | 3 +-
>>>>>>> 4 files changed, 51 insertions(+), 6 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>>>>>> b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>>>>>> index d87d1210365b..36651b447966 100644
>>>>>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>>>>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>>>>>>> @@ -210,7 +210,7 @@ static int i915_gem_vm_unbind_vma(struct
>>>>>>> i915_address_space *vm,
>>>>>>> */
>>>>>>> obj = vma->obj;
>>>>>>> i915_gem_object_lock(obj, NULL);
>>>>>>> - i915_vma_destroy(vma);
>>>>>>> + i915_vma_destroy_async(vma);
>>>>>>> i915_gem_object_unlock(obj);
>>>>>>> i915_gem_object_put(obj);
>>>>>>> diff --git a/drivers/gpu/drm/i915/i915_vma.c
>>>>>>> b/drivers/gpu/drm/i915/i915_vma.c
>>>>>>> index 7cf77c67d755..483d25f2425c 100644
>>>>>>> --- a/drivers/gpu/drm/i915/i915_vma.c
>>>>>>> +++ b/drivers/gpu/drm/i915/i915_vma.c
>>>>>>> @@ -42,6 +42,8 @@
>>>>>>> #include "i915_vma.h"
>>>>>>> #include "i915_vma_resource.h"
>>>>>>> +static struct dma_fence *__i915_vma_unbind_async(struct i915_vma
>>>>>>> *vma);
>>>>>>> +
>>>>>>> static inline void assert_vma_held_evict(const struct i915_vma
>>>>>>> *vma)
>>>>>>> {
>>>>>>> /*
>>>>>>> @@ -1713,7 +1715,7 @@ void i915_vma_reopen(struct i915_vma *vma)
>>>>>>> spin_unlock_irq(>->closed_lock);
>>>>>>> }
>>>>>>> -static void force_unbind(struct i915_vma *vma)
>>>>>>> +static void force_unbind(struct i915_vma *vma, bool async)
>>>>>>> {
>>>>>>> if (!drm_mm_node_allocated(&vma->node))
>>>>>>> return;
>>>>>>> @@ -1727,7 +1729,21 @@ static void force_unbind(struct i915_vma
>>>>>>> *vma)
>>>>>>> i915_vma_set_purged(vma);
>>>>>>> atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
>>>>>>> - WARN_ON(__i915_vma_unbind(vma));
>>>>>>> + if (async) {
>>>>>>> + struct dma_fence *fence;
>>>>>>> +
>>>>>>> + fence = __i915_vma_unbind_async(vma);
>>>>>>> + if (IS_ERR_OR_NULL(fence)) {
>>>>>>> + async = false;
>>>>>>> + } else {
>>>>>>> + dma_resv_add_fence(vma->obj->base.resv, fence,
>>>>>>> + DMA_RESV_USAGE_READ);
>>>>>>> + dma_fence_put(fence);
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (!async)
>>>>>>> + WARN_ON(__i915_vma_unbind(vma));
>>>>>>> GEM_BUG_ON(drm_mm_node_allocated(&vma->node));
>>>>>>> }
>>>>>>> @@ -1787,7 +1803,7 @@ void i915_vma_destroy_locked(struct
>>>>>>> i915_vma *vma)
>>>>>>> {
>>>>>>> lockdep_assert_held(&vma->vm->mutex);
>>>>>>> - force_unbind(vma);
>>>>>>> + force_unbind(vma, false);
>>>>>>> list_del_init(&vma->vm_link);
>>>>>>> release_references(vma, vma->vm->gt, false);
>>>>>>> }
>>>>>>> @@ -1798,7 +1814,34 @@ void i915_vma_destroy(struct i915_vma *vma)
>>>>>>> bool vm_ddestroy;
>>>>>>> mutex_lock(&vma->vm->mutex);
>>>>>>> - force_unbind(vma);
>>>>>>> + force_unbind(vma, false);
>>>>>>> + list_del_init(&vma->vm_link);
>>>>>>> + vm_ddestroy = vma->vm_ddestroy;
>>>>>>> + vma->vm_ddestroy = false;
>>>>>>> +
>>>>>>> + /* vma->vm may be freed when releasing vma->vm->mutex. */
>>>>>>> + gt = vma->vm->gt;
>>>>>>> + mutex_unlock(&vma->vm->mutex);
>>>>>>> + release_references(vma, gt, vm_ddestroy);
>>>>>>> +}
>>>>>>> +
>>>>>>> +void i915_vma_destroy_async(struct i915_vma *vma)
>>>>>>> +{
>>>>>>> + bool vm_ddestroy, async = vma->obj->mm.rsgt;
>>>>>>> + struct intel_gt *gt;
>>>>>>> +
>>>>>>> + if (dma_resv_reserve_fences(vma->obj->base.resv, 1))
>>>>>>> + async = false;
>>>>>>> +
>>>>>>> + mutex_lock(&vma->vm->mutex);
>>>>>>> + /*
>>>>>>> + * Ensure any asynchronous binding is complete while using
>>>>>>> + * async unbind as we will be releasing the vma here.
>>>>>>> + */
>>>>>>> + if (async && i915_active_wait(&vma->active))
>>>>>>> + async = false;
>>>>>>> +
>>>>>>> + force_unbind(vma, async);
>>>>>>> list_del_init(&vma->vm_link);
>>>>>>> vm_ddestroy = vma->vm_ddestroy;
>>>>>>> vma->vm_ddestroy = false;
>>>>>>> diff --git a/drivers/gpu/drm/i915/i915_vma.h
>>>>>>> b/drivers/gpu/drm/i915/i915_vma.h
>>>>>>> index 737ef310d046..25f15965dab8 100644
>>>>>>> --- a/drivers/gpu/drm/i915/i915_vma.h
>>>>>>> +++ b/drivers/gpu/drm/i915/i915_vma.h
>>>>>>> @@ -272,6 +272,7 @@ void i915_vma_reopen(struct i915_vma *vma);
>>>>>>> void i915_vma_destroy_locked(struct i915_vma *vma);
>>>>>>> void i915_vma_destroy(struct i915_vma *vma);
>>>>>>> +void i915_vma_destroy_async(struct i915_vma *vma);
>>>>>>> #define assert_vma_held(vma)
>>>>>>> dma_resv_assert_held((vma)->obj->base.resv)
>>>>>>> diff --git a/include/uapi/drm/i915_drm.h
>>>>>>> b/include/uapi/drm/i915_drm.h
>>>>>>> index e5600f358a15..431d40bb1dee 100644
>>>>>>> --- a/include/uapi/drm/i915_drm.h
>>>>>>> +++ b/include/uapi/drm/i915_drm.h
>>>>>>> @@ -3969,7 +3969,8 @@ struct drm_i915_gem_vm_bind {
>>>>>>> * any error.
>>>>>>> *
>>>>>>> * VM_BIND/UNBIND ioctl calls executed on different CPU threads
>>>>>>> concurrently
>>>>>>> - * are not ordered.
>>>>>>> + * are not ordered. Furthermore, parts of the VM_UNBIND
>>>>>>> operation can be done
>>>>>>> + * asynchronously.
>>>>>>> */
>>>>>>> struct drm_i915_gem_vm_unbind {
>>>>>>> /** @vm_id: VM (address space) id to bind */
More information about the dri-devel
mailing list