[Intel-gfx] [RFC 05/10] drm/i915/vm_bind: Handle persistent vmas
Niranjana Vishwanathapura
niranjana.vishwanathapura at intel.com
Fri Jul 8 15:06:07 UTC 2022
On Thu, Jul 07, 2022 at 04:27:23AM -0700, Hellstrom, Thomas wrote:
>On Fri, 2022-07-01 at 15:50 -0700, Niranjana Vishwanathapura wrote:
>> Treat VM_BIND vmas as persistent 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 at intel.com>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_object.c | 1 +
>> drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h | 3 +
>> .../drm/i915/gem/i915_gem_vm_bind_object.c | 12 ++-
>> drivers/gpu/drm/i915/gt/intel_gtt.c | 2 +
>> drivers/gpu/drm/i915/gt/intel_gtt.h | 2 +
>> drivers/gpu/drm/i915/i915_gem_gtt.h | 22 ++++++
>> drivers/gpu/drm/i915/i915_vma.c | 32 +++++++-
>> drivers/gpu/drm/i915/i915_vma.h | 78
>> +++++++++++++++++--
>> drivers/gpu/drm/i915/i915_vma_types.h | 23 ++++++
>> 9 files changed, 163 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_object.c
>> index ccec4055fde3..5121f02ba95c 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
>> @@ -38,6 +38,7 @@
>> #include "i915_gem_mman.h"
>> #include "i915_gem_object.h"
>> #include "i915_gem_ttm.h"
>> +#include "i915_gem_vm_bind.h"
>> #include "i915_memcpy.h"
>> #include "i915_trace.h"
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> index 849bf3c1061e..eaadf5a6ab09 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> @@ -6,6 +6,7 @@
>> #ifndef __I915_GEM_VM_BIND_H
>> #define __I915_GEM_VM_BIND_H
>>
>> +#include <linux/dma-resv.h>
>> #include "i915_drv.h"
>>
>> #define assert_vm_bind_held(vm) lockdep_assert_held(&(vm)-
>> >vm_bind_lock)
>> @@ -26,6 +27,8 @@ static inline void i915_gem_vm_bind_unlock(struct
>> i915_address_space *vm)
>> mutex_unlock(&vm->vm_bind_lock);
>> }
>>
>> +#define assert_vm_priv_held(vm) assert_object_held((vm)->root_obj)
>> +
>> static inline int i915_gem_vm_priv_lock(struct i915_address_space
>> *vm,
>> struct i915_gem_ww_ctx *ww)
>> {
>> 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 96f139cc8060..1a8efa83547f 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
>> @@ -85,6 +85,13 @@ void i915_gem_vm_bind_remove(struct i915_vma *vma,
>> bool release_obj)
>> {
>> assert_vm_bind_held(vma->vm);
>>
>> + 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);
>> + i915_vma_set_freed(vma);
>
>Following the vma destruction discussion, can we ditch the freed flag
>now?
Yes
>
>> + spin_unlock(&vma->vm->vm_rebind_lock);
>> +
>> if (!list_empty(&vma->vm_bind_link)) {
>> list_del_init(&vma->vm_bind_link);
>> list_del_init(&vma->non_priv_vm_bind_link);
>> @@ -220,6 +227,7 @@ 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;
>> }
>> @@ -304,8 +312,10 @@ int i915_gem_vm_bind_obj(struct
>> i915_address_space *vm,
>>
>> i915_vm_bind_put_fence(vma);
>> put_vma:
>> - if (ret)
>> + if (ret) {
>> + i915_vma_set_freed(vma);
>> i915_vma_destroy(vma);
>> + }
>>
>> i915_gem_ww_ctx_fini(&ww);
>> unlock_vm:
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c
>> b/drivers/gpu/drm/i915/gt/intel_gtt.c
>> index df0a8459c3c6..55d5389b2c6c 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
>> @@ -293,6 +293,8 @@ 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 f538ce9115c9..fe5485c4a1cd 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> @@ -265,6 +265,8 @@ struct i915_address_space {
>> struct mutex vm_bind_lock; /* Protects vm_bind lists */
>> struct list_head vm_bind_list;
>> struct list_head vm_bound_list;
>> + struct list_head vm_rebind_list;
>> + spinlock_t vm_rebind_lock; /* Protects vm_rebind_list */
>> /* 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.h
>> b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> index 8c2f57eb5dda..09b89d1913fc 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> @@ -51,4 +51,26 @@ int i915_gem_gtt_insert(struct i915_address_space
>> *vm,
>>
>> #define PIN_OFFSET_MASK I915_GTT_PAGE_MASK
>>
>> +static inline int i915_vm_sync(struct i915_address_space *vm)
>
>No need to make this an inline function. Only for performance reasons.
>Kerneldoc.
>
>> +{
>> + 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;
>> +}
>> +
>> +static inline 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);
>> +}
>> +
>> #endif
>> diff --git a/drivers/gpu/drm/i915/i915_vma.c
>> b/drivers/gpu/drm/i915/i915_vma.c
>> index 6737236b7884..6adb013579be 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:
>> @@ -1622,7 +1623,8 @@ void i915_vma_close(struct i915_vma *vma)
>> if (atomic_dec_and_lock_irqsave(&vma->open_count,
>> >->closed_lock,
>> flags)) {
>> - __vma_close(vma, gt);
>> + if (!i915_vma_is_persistent(vma))
>> + __vma_close(vma, gt);
>
>This change is not needed since persistent vmas shouldn't take part in
>the other vma open-close life-time management.
Yah, looks like a relic from when we did not have separate execbuf3.
Should be removed.
>
>> spin_unlock_irqrestore(>->closed_lock, flags);
>> }
>> }
>> @@ -1647,6 +1649,13 @@ 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));
>> @@ -1666,9 +1675,12 @@ static void release_references(struct i915_vma
>> *vma, bool vm_ddestroy)
>>
>> spin_unlock(&obj->vma.lock);
>>
>> - i915_gem_vm_bind_lock(vma->vm);
>> - i915_gem_vm_bind_remove(vma, true);
>> - i915_gem_vm_bind_unlock(vma->vm);
>> + if (i915_vma_is_persistent(vma) &&
>> + !i915_vma_is_freed(vma)) {
>> + i915_gem_vm_bind_lock(vma->vm);
>> + i915_gem_vm_bind_remove(vma, true);
>> + i915_gem_vm_bind_unlock(vma->vm);
>> + }
>>
>> spin_lock_irq(>->closed_lock);
>> __i915_vma_remove_closed(vma);
>> @@ -1839,6 +1851,8 @@ 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);
>>
>> @@ -1999,6 +2013,16 @@ 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;
>> }
>>
>> diff --git a/drivers/gpu/drm/i915/i915_vma.h
>> b/drivers/gpu/drm/i915/i915_vma.h
>> index dcb49f79ff7e..6c1369a40e03 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 +132,48 @@ 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_freed(const struct i915_vma *vma)
>> +{
>> + return test_bit(I915_VMA_FREED_BIT, __i915_vma_flags(vma));
>> +}
>> +
>> +static inline void i915_vma_set_freed(struct i915_vma *vma)
>> +{
>> + set_bit(I915_VMA_FREED_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);
>> @@ -408,8 +444,36 @@ int i915_vma_wait_for_bind(struct i915_vma
>> *vma);
>>
>> static inline int i915_vma_sync(struct i915_vma *vma)
>> {
>> + int ret;
>> +
>> /* Wait for the asynchronous bindings and pending GPU reads
>> */
>> - return i915_active_wait(&vma->active);
>> + 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);
>> +}
>> +
>> +static inline bool i915_vma_is_bind_complete(struct i915_vma *vma)
>> +{
>> + /* Ensure vma bind is initiated */
>> + if (!i915_vma_is_bound(vma, I915_VMA_BIND_MASK))
>> + return false;
>> +
>> + /* Ensure any binding started is complete */
>> + if (rcu_access_pointer(vma->active.excl.fence)) {
>> + struct dma_fence *fence;
>> +
>> + rcu_read_lock();
>> + fence = dma_fence_get_rcu_safe(&vma-
>> >active.excl.fence);
>> + rcu_read_unlock();
>> + if (fence) {
>> + dma_fence_put(fence);
>> + return false;
>> + }
>> + }
>
>Could we use i915_active_fence_get() instead of first testing the
>pointer and then open-coding i915_active_fence_get()? Also no need to
>inline this.
Yah. Looks like we can also use i915_vma_verify_bind_complete() (just
move it out of I915_DEBUG_GEM).
Niranjana
>
>> +
>> + return true;
>> }
>>
>> /**
>> diff --git a/drivers/gpu/drm/i915/i915_vma_types.h
>> b/drivers/gpu/drm/i915/i915_vma_types.h
>> index 7d830a6a0b51..405c82e1bc30 100644
>> --- a/drivers/gpu/drm/i915/i915_vma_types.h
>> +++ b/drivers/gpu/drm/i915/i915_vma_types.h
>> @@ -264,6 +264,28 @@ 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.
>> + *
>> + * I915_VMA_FREED_BIT:
>> + * The persistent vma is being released by UMD via VM_UNBIND call.
>> + * While releasing the vma, do not take VM_BIND lock as VM_UNBIND
>> call
>> + * already holds the lock.
>> + */
>> +#define I915_VMA_PERSISTENT_BIT 19
>> +#define I915_VMA_PURGED_BIT 20
>> +#define I915_VMA_FREED_BIT 21
>> +
>> +#define I915_VMA_PERSISTENT ((int)BIT(I915_VMA_PERSISTENT_BIT))
>> +#define
>> I915_VMA_PURGED ((int)BIT(I915_VMA_PURGED_BIT))
>> +#define I915_VMA_FREED ((int)BIT(I915_VMA_FREED_BIT))
>> +
>> struct i915_active active;
>>
>> #define I915_VMA_PAGES_BIAS 24
>> @@ -292,6 +314,7 @@ struct i915_vma {
>> struct list_head vm_bind_link; /* Link in persistent VMA list
>> */
>Protected by..
>
>> /* Link in non-private persistent VMA list */
>> struct list_head non_priv_vm_bind_link;
>> + struct list_head vm_rebind_link; /* Link in vm_rebind_list */
>>
>> /** Timeline fence for vm_bind completion notification */
>> struct {
>
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