Re: [Intel-gfx] [RFC PATCH v3 07/17] drm/i915/vm_bind: Handle persistent vmas

Niranjana Vishwanathapura
2022-09-21T07:22:07Z

On Mon, Sep 12, 2022 at 04:16:06PM +0300, Jani Nikula wrote:
>On Sat, 27 Aug 2022, Andi Shyti <andi.shyti@linux.intel.com> wrote:
>> From: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>>
>> 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@intel.com>
>> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_object.c | 1 +
>> .../drm/i915/gem/i915_gem_vm_bind_object.c | 8 +++
>> 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 | 38 +++++++++++++
>> drivers/gpu/drm/i915/i915_gem_gtt.h | 3 +
>> drivers/gpu/drm/i915/i915_vma.c | 50 +++++++++++++++--
>> drivers/gpu/drm/i915/i915_vma.h | 56 +++++++++++++++----
>> drivers/gpu/drm/i915/i915_vma_types.h | 24 ++++++++
>> 9 files changed, 169 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
>> index 389e9f157ca5e..825dce41f7113 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"
>
>Why do you add this here if you're not using anything from there?

Addressed in v4 rfc series.

>
>> #include "i915_memcpy.h"
>> #include "i915_trace.h"
>>
>> 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 9ff929f187cfd..3b45529fe8d4c 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 +91,13 @@ 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);
>> + i915_vma_set_freed(vma);
>> + 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);
>> @@ -190,6 +197,7 @@ 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 c4f75826213ae..97cd0089b516d 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 9a2665e4ec2e5..1f3b1967ec175 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> @@ -265,6 +265,10 @@ 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 329ff75b80b97..f083724163deb 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> @@ -25,6 +25,44 @@
>> #include "i915_trace.h"
>> #include "i915_vgpu.h"
>>
>> +/**
>> + * i915_vm_sync() - Wait for all requests on private vmas of a vm to be completed
>> + * @vm: address space we need to wait for idle
>> + *
>> + * Waits till all requests of the vm_binded private objs are completed.
>> + *
>> + * Returns: 0 on success -ve errcode on 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 for activeness of requests of vm
>> + * @vm: address spece targetted
>> + *
>> + * Check whether all the requests related private vmas are completed or not
>> + *
>> + * Returns: True when requests are not completed yet. Flase 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 8c2f57eb5ddaa..a5bbdc59d9dfb 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);
>
>Maybe I don't get the gem header structure, but why do you add these in
>i915_gem_gtt.h but the implementation in i915_vma.c?
>
>In general, declarations for stuff in i915_foo.c should be in
>i915_foo.h.

These are _vm_ functions (not _vma_ functions), hence they are here.

Niranjana

>
>BR,
>Jani.
>
>> +
>> #endif
>> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
>> index 239346e0c07f2..0eb7727d62a6f 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:
>> @@ -387,8 +388,31 @@ int i915_vma_wait_for_bind(struct i915_vma *vma)
>> return err;
>> }
>>
>> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
>> -static int i915_vma_verify_bind_complete(struct i915_vma *vma)
>> +/**
>> + * 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);
>> +}
>> +
>> +/**
>> + * i915_vma_verify_bind_complete() - Check for the vm_bind completion of the vma
>> + * @vma: vma submitted for vm_bind
>> + *
>> + * Returns: 0 if the vm_bind is completed. Error code otherwise.
>> + */
>> +int i915_vma_verify_bind_complete(struct i915_vma *vma)
>> {
>> struct dma_fence *fence = i915_active_fence_get(&vma->active.excl);
>> int err;
>> @@ -405,9 +429,6 @@ static int i915_vma_verify_bind_complete(struct i915_vma *vma)
>>
>> return err;
>> }
>> -#else
>> -#define i915_vma_verify_bind_complete(_vma) 0
>> -#endif
>>
>> I915_SELFTEST_EXPORT void
>> i915_vma_resource_init_from_vma(struct i915_vma_resource *vma_res,
>> @@ -1654,6 +1675,13 @@ 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 +1874,8 @@ 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);
>>
>> @@ -2014,6 +2044,16 @@ 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 15eac55a3e274..bf0b5b4abd919 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);
>> @@ -406,12 +442,8 @@ 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_verify_bind_complete(struct i915_vma *vma);
>> +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 de5534d518cdd..5483ccf0c82c7 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
>> @@ -293,6 +315,8 @@ 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 */
>
>--
>Jani Nikula, Intel Open Source Graphics Center