Regards,
Oak
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Niranjana
> Vishwanathapura
> Sent: September 21, 2022 3:10 AM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Zanoni, Paulo R <paulo.r.zanoni@xxxxxxxxx>; Hellstrom, Thomas
> <thomas.hellstrom@xxxxxxxxx>; Auld, Matthew <matthew.auld@xxxxxxxxx>; Vetter,
> Daniel <daniel.vetter@xxxxxxxxx>; christian.koenig@xxxxxxx
> Subject: [RFC v4 06/14] drm/i915/vm_bind: Handle persistent vmas
>
> Treat VM_BIND vmas as persistent across execbuf ioctl calls and handle
> them during the request submission in the execbuff path.
>
> Support eviction by maintaining a list of evicted persistent vmas
> for rebinding during next submission.
>
> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
> Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> ---
> .../drm/i915/gem/i915_gem_vm_bind_object.c | 7 +++
> drivers/gpu/drm/i915/gt/intel_gtt.c | 2 +
> drivers/gpu/drm/i915/gt/intel_gtt.h | 4 ++
> drivers/gpu/drm/i915/i915_gem_gtt.c | 39 ++++++++++++++++
> drivers/gpu/drm/i915/i915_gem_gtt.h | 3 ++
> drivers/gpu/drm/i915/i915_vma.c | 46 +++++++++++++++++++
> drivers/gpu/drm/i915/i915_vma.h | 45 +++++++++++++-----
> drivers/gpu/drm/i915/i915_vma_types.h | 17 +++++++
> 8 files changed, 151 insertions(+), 12 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 7ca6a41fc981..236f901b8b9c 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
> @@ -91,6 +91,12 @@ static void i915_gem_vm_bind_remove(struct i915_vma
> *vma, bool release_obj)
> {
> lockdep_assert_held(&vma->vm->vm_bind_lock);
>
> + spin_lock(&vma->vm->vm_rebind_lock);
> + if (!list_empty(&vma->vm_rebind_link))
> + list_del_init(&vma->vm_rebind_link);
> + i915_vma_set_purged(vma);
> + spin_unlock(&vma->vm->vm_rebind_lock);
> +
> list_del_init(&vma->vm_bind_link);
> list_del_init(&vma->non_priv_vm_bind_link);
> i915_vm_bind_it_remove(vma, &vma->vm->va);
> @@ -181,6 +187,7 @@ static struct i915_vma *vm_bind_get_vma(struct
> i915_address_space *vm,
>
> vma->start = va->start;
> vma->last = va->start + va->length - 1;
> + i915_vma_set_persistent(vma);
>
> return vma;
> }
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c
> b/drivers/gpu/drm/i915/gt/intel_gtt.c
> index da4f9dee0397..6db31197fa87 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
> @@ -296,6 +296,8 @@ void i915_address_space_init(struct i915_address_space
> *vm, int subclass)
> INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
> vm->root_obj = i915_gem_object_create_internal(vm->i915, PAGE_SIZE);
> GEM_BUG_ON(IS_ERR(vm->root_obj));
> + INIT_LIST_HEAD(&vm->vm_rebind_list);
> + spin_lock_init(&vm->vm_rebind_lock);
> }
>
> void *__px_vaddr(struct drm_i915_gem_object *p)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h
> b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index 3f2e87d3bf34..b73d35b4e05d 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -273,6 +273,10 @@ struct i915_address_space {
> struct list_head vm_bind_list;
> /** @vm_bound_list: List of vm_binding completed */
> struct list_head vm_bound_list;
> + /* @vm_rebind_list: list of vmas to be rebinded */
> + struct list_head vm_rebind_list;
> + /* @vm_rebind_lock: protects vm_rebound_list */
> + spinlock_t vm_rebind_lock;
> /* @va: tree of persistent vmas */
> struct rb_root_cached va;
> struct list_head non_priv_vm_bind_list;
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 329ff75b80b9..b7d0844de561 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -25,6 +25,45 @@
> #include "i915_trace.h"
> #include "i915_vgpu.h"
>
> +/**
> + * i915_vm_sync() - Wait until address space is not in use
> + * @vm: address space
> + *
> + * Waits until all requests using the address space are complete.
> + *
> + * Returns: 0 if success, -ve err code upon failure
> + */
> +int i915_vm_sync(struct i915_address_space *vm)
> +{
> + int ret;
> +
> + /* Wait for all requests under this vm to finish */
> + ret = dma_resv_wait_timeout(vm->root_obj->base.resv,
> + DMA_RESV_USAGE_BOOKKEEP, false,
> + MAX_SCHEDULE_TIMEOUT);
> + if (ret < 0)
> + return ret;
> + else if (ret > 0)
> + return 0;
> + else
> + return -ETIMEDOUT;
> +}
> +
> +/**
> + * i915_vm_is_active() - Check if address space is being used
> + * @vm: address space
> + *
> + * Check if any request using the specified address space is
> + * active.
> + *
> + * Returns: true if address space is active, false otherwise.
> + */
> +bool i915_vm_is_active(const struct i915_address_space *vm)
> +{
> + return !dma_resv_test_signaled(vm->root_obj->base.resv,
> + DMA_RESV_USAGE_BOOKKEEP);
> +}
> +
> int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj,
> struct sg_table *pages)
> {
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h
> b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index 8c2f57eb5dda..a5bbdc59d9df 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -51,4 +51,7 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
>
> #define PIN_OFFSET_MASK I915_GTT_PAGE_MASK
>
> +int i915_vm_sync(struct i915_address_space *vm);
> +bool i915_vm_is_active(const struct i915_address_space *vm);
> +
> #endif
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index aa332ad69ec2..ff216e9a2c8d 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -237,6 +237,7 @@ vma_create(struct drm_i915_gem_object *obj,
>
> INIT_LIST_HEAD(&vma->vm_bind_link);
> INIT_LIST_HEAD(&vma->non_priv_vm_bind_link);
> + INIT_LIST_HEAD(&vma->vm_rebind_link);
> return vma;
>
> err_unlock:
> @@ -387,6 +388,24 @@ int i915_vma_wait_for_bind(struct i915_vma *vma)
> return err;
> }
>
> +/**
> + * i915_vma_sync() - Wait for the vma to be idle
> + * @vma: vma to be tested
> + *
> + * Returns 0 on success and error code on failure
> + */
> +int i915_vma_sync(struct i915_vma *vma)
> +{
> + int ret;
> +
> + /* Wait for the asynchronous bindings and pending GPU reads */
> + ret = i915_active_wait(&vma->active);
> + if (ret || !i915_vma_is_persistent(vma) || i915_vma_is_purged(vma))
> + return ret;
> +
> + return i915_vm_sync(vma->vm);
Hi, I try to understand why we call vm_sync here. As I understand it, each vm has many vmas. The vma_sync function wait for a single vma to be idle, for example, wait for all the request/gpu task using this vma to complete. While vm_sync wait for the whole vm to be idle. To me vm_sync essentially wait for all the vmas in this vm to be idle. Isn't it?
Thanks,
Oak
> +}
> +
> #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
> static int i915_vma_verify_bind_complete(struct i915_vma *vma)
> {
> @@ -1654,6 +1673,13 @@ static void force_unbind(struct i915_vma *vma)
> if (!drm_mm_node_allocated(&vma->node))
> return;
>
> + /*
> + * Mark persistent vma as purged to avoid it waiting
> + * for VM to be released.
> + */
> + if (i915_vma_is_persistent(vma))
> + i915_vma_set_purged(vma);
> +
> atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
> WARN_ON(__i915_vma_unbind(vma));
> GEM_BUG_ON(drm_mm_node_allocated(&vma->node));
> @@ -1846,6 +1872,8 @@ int _i915_vma_move_to_active(struct i915_vma *vma,
> int err;
>
> assert_object_held(obj);
> + if (i915_vma_is_persistent(vma))
> + return -EINVAL;
>
> GEM_BUG_ON(!vma->pages);
>
> @@ -2015,6 +2043,16 @@ int __i915_vma_unbind(struct i915_vma *vma)
> __i915_vma_evict(vma, false);
>
> drm_mm_remove_node(&vma->node); /* pairs with i915_vma_release() */
> +
> + if (i915_vma_is_persistent(vma)) {
> + spin_lock(&vma->vm->vm_rebind_lock);
> + if (list_empty(&vma->vm_rebind_link) &&
> + !i915_vma_is_purged(vma))
> + list_add_tail(&vma->vm_rebind_link,
> + &vma->vm->vm_rebind_list);
> + spin_unlock(&vma->vm->vm_rebind_lock);
> + }
> +
> return 0;
> }
>
> @@ -2046,6 +2084,14 @@ static struct dma_fence
> *__i915_vma_unbind_async(struct i915_vma *vma)
> return ERR_PTR(-EBUSY);
> }
>
> + if (__i915_sw_fence_await_reservation(&vma->resource->chain,
> + vma->obj->base.resv,
> + DMA_RESV_USAGE_BOOKKEEP,
> + i915_fence_timeout(vma->vm->i915),
> + I915_FENCE_GFP) < 0) {
> + return ERR_PTR(-EBUSY);
> + }
> +
> fence = __i915_vma_evict(vma, true);
>
> drm_mm_remove_node(&vma->node); /* pairs with i915_vma_release() */
> diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
> index 6feef0305fe1..aa536c9ce472 100644
> --- a/drivers/gpu/drm/i915/i915_vma.h
> +++ b/drivers/gpu/drm/i915/i915_vma.h
> @@ -47,12 +47,6 @@ i915_vma_instance(struct drm_i915_gem_object *obj,
>
> void i915_vma_unpin_and_release(struct i915_vma **p_vma, unsigned int flags);
> #define I915_VMA_RELEASE_MAP BIT(0)
> -
> -static inline bool i915_vma_is_active(const struct i915_vma *vma)
> -{
> - return !i915_active_is_idle(&vma->active);
> -}
> -
> /* do not reserve memory to prevent deadlocks */
> #define __EXEC_OBJECT_NO_RESERVE BIT(31)
>
> @@ -138,6 +132,38 @@ static inline u32 i915_ggtt_pin_bias(struct i915_vma *vma)
> return i915_vm_to_ggtt(vma->vm)->pin_bias;
> }
>
> +static inline bool i915_vma_is_persistent(const struct i915_vma *vma)
> +{
> + return test_bit(I915_VMA_PERSISTENT_BIT, __i915_vma_flags(vma));
> +}
> +
> +static inline void i915_vma_set_persistent(struct i915_vma *vma)
> +{
> + set_bit(I915_VMA_PERSISTENT_BIT, __i915_vma_flags(vma));
> +}
> +
> +static inline bool i915_vma_is_purged(const struct i915_vma *vma)
> +{
> + return test_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
> +}
> +
> +static inline void i915_vma_set_purged(struct i915_vma *vma)
> +{
> + set_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
> +}
> +
> +static inline bool i915_vma_is_active(const struct i915_vma *vma)
> +{
> + if (i915_vma_is_persistent(vma)) {
> + if (i915_vma_is_purged(vma))
> + return false;
> +
> + return i915_vm_is_active(vma->vm);
> + }
> +
> + return !i915_active_is_idle(&vma->active);
> +}
> +
> static inline struct i915_vma *i915_vma_get(struct i915_vma *vma)
> {
> i915_gem_object_get(vma->obj);
> @@ -406,12 +432,7 @@ void i915_vma_make_shrinkable(struct i915_vma *vma);
> void i915_vma_make_purgeable(struct i915_vma *vma);
>
> int i915_vma_wait_for_bind(struct i915_vma *vma);
> -
> -static inline int i915_vma_sync(struct i915_vma *vma)
> -{
> - /* Wait for the asynchronous bindings and pending GPU reads */
> - return i915_active_wait(&vma->active);
> -}
> +int i915_vma_sync(struct i915_vma *vma);
>
> /**
> * i915_vma_get_current_resource - Get the current resource of the vma
> diff --git a/drivers/gpu/drm/i915/i915_vma_types.h
> b/drivers/gpu/drm/i915/i915_vma_types.h
> index 6d727c2d9802..d21bf97febaa 100644
> --- a/drivers/gpu/drm/i915/i915_vma_types.h
> +++ b/drivers/gpu/drm/i915/i915_vma_types.h
> @@ -264,6 +264,21 @@ struct i915_vma {
> #define I915_VMA_SCANOUT_BIT 17
> #define I915_VMA_SCANOUT ((int)BIT(I915_VMA_SCANOUT_BIT))
>
> + /**
> + * I915_VMA_PERSISTENT_BIT:
> + * The vma is persistent (created with VM_BIND call).
> + *
> + * I915_VMA_PURGED_BIT:
> + * The persistent vma is force unbound either due to VM_UNBIND call
> + * from UMD or VM is released. Do not check/wait for VM activeness
> + * in i915_vma_is_active() and i915_vma_sync() calls.
> + */
> +#define I915_VMA_PERSISTENT_BIT 19
> +#define I915_VMA_PURGED_BIT 20
> +
> +#define I915_VMA_PERSISTENT ((int)BIT(I915_VMA_PERSISTENT_BIT))
> +#define I915_VMA_PURGED ((int)BIT(I915_VMA_PURGED_BIT))
> +
> struct i915_active active;
>
> #define I915_VMA_PAGES_BIAS 24
> @@ -293,6 +308,8 @@ struct i915_vma {
> struct list_head vm_bind_link;
> /* @non_priv_vm_bind_link: Link in non-private persistent VMA list */
> struct list_head non_priv_vm_bind_link;
> + /* @vm_rebind_link: link to vm_rebind_list and protected by
> vm_rebind_lock */
> + struct list_head vm_rebind_link; /* Link in vm_rebind_list */
>
> /** Interval tree structures for persistent vma */
>
> --
> 2.21.0.rc0.32.g243a4c7e27
