Re: [PATCH 21/29] drm/i915: mm_list is per VMA

Daniel Vetter
2013-08-06T19:38:34Z

On Wed, Jul 31, 2013 at 05:00:14PM -0700, Ben Widawsky wrote:
> formerly: "drm/i915: Create VMAs (part 5) - move mm_list"
>
> The mm_list is used for the active/inactive LRUs. Since those LRUs are
> per address space, the link should be per VMx .
>
> Because we'll only ever have 1 VMA before this point, it's not incorrect
> to defer this change until this point in the patch series, and doing it
> here makes the change much easier to understand.
>
> Shamelessly manipulated out of Daniel:
> "active/inactive stuff is used by eviction when we run out of address
> space, so needs to be per-vma and per-address space. Bound/unbound otoh
> is used by the shrinker which only cares about the amount of memory used
> and not one bit about in which address space this memory is all used in.
> Of course to actual kick out an object we need to unbind it from every
> address space, but for that we have the per-object list of vmas."
>
> v2: only bump GGTT LRU in i915_gem_object_set_to_gtt_domain (Chris)
>
> v3: Moved earlier in the series
>
> v4: Add dropped message from v3
>
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

Some comments below for this one. The lru changes look a bit strange so
I'll wait for your confirmation that the do_switch hunk has the same
reasons s the one in execbuf with the FIXME comment.
-Daniel

> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 53 ++++++++++++++++++++----------
> drivers/gpu/drm/i915/i915_drv.h | 5 +--
> drivers/gpu/drm/i915/i915_gem.c | 37 +++++++++++----------
> drivers/gpu/drm/i915/i915_gem_context.c | 3 ++
> drivers/gpu/drm/i915/i915_gem_evict.c | 14 ++++----
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 ++
> drivers/gpu/drm/i915/i915_gem_stolen.c | 2 +-
> drivers/gpu/drm/i915/i915_gpu_error.c | 37 ++++++++++++---------
> 8 files changed, 91 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 6d5ca85bd..181e5a6 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -149,7 +149,7 @@ static int i915_gem_object_list_info(struct seq_file *m, void *data)
> struct drm_device *dev = node->minor->dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct i915_address_space *vm = &dev_priv->gtt.base;
> - struct drm_i915_gem_object *obj;
> + struct i915_vma *vma;
> size_t total_obj_size, total_gtt_size;
> int count, ret;
>
> @@ -157,6 +157,7 @@ static int i915_gem_object_list_info(struct seq_file *m, void *data)
> if (ret)
> return ret;
>
> + /* FIXME: the user of this interface might want more than just GGTT */
> switch (list) {
> case ACTIVE_LIST:
> seq_puts(m, "Active:\n");
> @@ -172,12 +173,12 @@ static int i915_gem_object_list_info(struct seq_file *m, void *data)
> }
>
> total_obj_size = total_gtt_size = count = 0;
> - list_for_each_entry(obj, head, mm_list) {
> - seq_puts(m, " ");
> - describe_obj(m, obj);
> - seq_putc(m, '\n');
> - total_obj_size += obj->base.size;
> - total_gtt_size += i915_gem_obj_ggtt_size(obj);
> + list_for_each_entry(vma, head, mm_list) {
> + seq_printf(m, " ");
> + describe_obj(m, vma->obj);
> + seq_printf(m, "\n");
> + total_obj_size += vma->obj->base.size;
> + total_gtt_size += i915_gem_obj_size(vma->obj, vma->vm);

Why not use vma->node.size? If you don't disagree I'll bikeshed this while
applying.

> count++;
> }
> mutex_unlock(&dev->struct_mutex);
> @@ -224,7 +225,18 @@ static int per_file_stats(int id, void *ptr, void *data)
> return 0;
> }
>
> -static int i915_gem_object_info(struct seq_file *m, void *data)
> +#define count_vmas(list, member) do { \
> + list_for_each_entry(vma, list, member) { \
> + size += i915_gem_obj_ggtt_size(vma->obj); \
> + ++count; \
> + if (vma->obj->map_and_fenceable) { \
> + mappable_size += i915_gem_obj_ggtt_size(vma->obj); \
> + ++mappable_count; \
> + } \
> + } \
> +} while (0)
> +
> +static int i915_gem_object_info(struct seq_file *m, void* data)
> {
> struct drm_info_node *node = (struct drm_info_node *) m->private;
> struct drm_device *dev = node->minor->dev;
> @@ -234,6 +246,7 @@ static int i915_gem_object_info(struct seq_file *m, void *data)
> struct drm_i915_gem_object *obj;
> struct i915_address_space *vm = &dev_priv->gtt.base;
> struct drm_file *file;
> + struct i915_vma *vma;
> int ret;
>
> ret = mutex_lock_interruptible(&dev->struct_mutex);
> @@ -253,12 +266,12 @@ static int i915_gem_object_info(struct seq_file *m, void *data)
> count, mappable_count, size, mappable_size);
>
> size = count = mappable_size = mappable_count = 0;
> - count_objects(&vm->active_list, mm_list);
> + count_vmas(&vm->active_list, mm_list);
> seq_printf(m, " %u [%u] active objects, %zu [%zu] bytes\n",
> count, mappable_count, size, mappable_size);
>
> size = count = mappable_size = mappable_count = 0;
> - count_objects(&vm->inactive_list, mm_list);
> + count_vmas(&vm->inactive_list, mm_list);
> seq_printf(m, " %u [%u] inactive objects, %zu [%zu] bytes\n",
> count, mappable_count, size, mappable_size);
>
> @@ -1771,7 +1784,8 @@ i915_drop_caches_set(void *data, u64 val)
> struct drm_device *dev = data;
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct drm_i915_gem_object *obj, *next;
> - struct i915_address_space *vm = &dev_priv->gtt.base;
> + struct i915_address_space *vm;
> + struct i915_vma *vma, *x;
> int ret;
>
> DRM_DEBUG_DRIVER("Dropping caches: 0x%08llx\n", val);
> @@ -1792,13 +1806,16 @@ i915_drop_caches_set(void *data, u64 val)
> i915_gem_retire_requests(dev);
>
> if (val & DROP_BOUND) {
> - list_for_each_entry_safe(obj, next, &vm->inactive_list,
> - mm_list) {
> - if (obj->pin_count)
> - continue;
> - ret = i915_gem_object_ggtt_unbind(obj);
> - if (ret)
> - goto unlock;
> + list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
> + list_for_each_entry_safe(vma, x, &vm->inactive_list,
> + mm_list) {

Imo the double-loop is a bit funny, looping over the global bound list
and skipping all active objects is imo the more straightfoward logic. But
I agree that this is the more straightforward conversion, so I'm ok with a
follow-up fixup patch.

> + if (vma->obj->pin_count)
> + continue;
> +
> + ret = i915_vma_unbind(vma);
> + if (ret)
> + goto unlock;
> + }
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index bf1ecef..220699b 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -546,6 +546,9 @@ struct i915_vma {
> struct drm_i915_gem_object *obj;
> struct i915_address_space *vm;
>
> + /** This object's place on the active/inactive lists */
> + struct list_head mm_list;
> +
> struct list_head vma_link; /* Link in the object's VMA list */
> };
>
> @@ -1263,9 +1266,7 @@ struct drm_i915_gem_object {
> struct drm_mm_node *stolen;
> struct list_head global_list;
>
> - /** This object's place on the active/inactive lists */
> struct list_head ring_list;
> - struct list_head mm_list;
> /** This object's place in the batchbuffer or on the eviction list */
> struct list_head exec_list;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index ec23a5c..fb3f02f 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1872,7 +1872,6 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
> {
> struct drm_device *dev = obj->base.dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> - struct i915_address_space *vm = &dev_priv->gtt.base;
> u32 seqno = intel_ring_get_seqno(ring);
>
> BUG_ON(ring == NULL);
> @@ -1888,8 +1887,6 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
> obj->active = 1;
> }
>
> - /* Move from whatever list we were on to the tail of execution. */
> - list_move_tail(&obj->mm_list, &vm->active_list);
> list_move_tail(&obj->ring_list, &ring->active_list);
>
> obj->last_read_seqno = seqno;
> @@ -1911,14 +1908,14 @@ i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
> static void
> i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
> {
> - struct drm_device *dev = obj->base.dev;
> - struct drm_i915_private *dev_priv = dev->dev_private;
> - struct i915_address_space *vm = &dev_priv->gtt.base;
> + struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
> + struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
> + struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
>
> BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
> BUG_ON(!obj->active);
>
> - list_move_tail(&obj->mm_list, &vm->inactive_list);
> + list_move_tail(&vma->mm_list, &ggtt_vm->inactive_list);
>
> list_del_init(&obj->ring_list);
> obj->ring = NULL;
> @@ -2286,9 +2283,9 @@ void i915_gem_restore_fences(struct drm_device *dev)
> void i915_gem_reset(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> - struct i915_address_space *vm;
> - struct drm_i915_gem_object *obj;
> struct intel_ring_buffer *ring;
> + struct i915_address_space *vm;
> + struct i915_vma *vma;
> int i;
>
> for_each_ring(ring, dev_priv, i)
> @@ -2298,8 +2295,8 @@ void i915_gem_reset(struct drm_device *dev)
> * necessary invalidation upon reuse.
> */
> list_for_each_entry(vm, &dev_priv->vm_list, global_link)
> - list_for_each_entry(obj, &vm->inactive_list, mm_list)
> - obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
> + list_for_each_entry(vma, &vm->inactive_list, mm_list)
> + vma->obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
>
> i915_gem_restore_fences(dev);
> }
> @@ -2353,6 +2350,7 @@ i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
> if (!i915_seqno_passed(seqno, obj->last_read_seqno))
> break;
>
> + BUG_ON(!obj->active);
> i915_gem_object_move_to_inactive(obj);
> }
>
> @@ -2635,7 +2633,6 @@ int i915_vma_unbind(struct i915_vma *vma)
> i915_gem_gtt_finish_object(obj);
> i915_gem_object_unpin_pages(obj);
>
> - list_del(&obj->mm_list);
> /* Avoid an unnecessary call to unbind on rebind. */
> if (i915_is_ggtt(vma->vm))
> obj->map_and_fenceable = true;
> @@ -3180,7 +3177,7 @@ search_free:
> goto err_out;
>
> list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
> - list_add_tail(&obj->mm_list, &vm->inactive_list);
> + list_add_tail(&vma->mm_list, &vm->inactive_list);
>
> /* Keep GGTT vmas first to make debug easier */
> if (i915_is_ggtt(vm))
> @@ -3342,9 +3339,14 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
> old_write_domain);
>
> /* And bump the LRU for this access */
> - if (i915_gem_object_is_inactive(obj))
> - list_move_tail(&obj->mm_list,
> - &dev_priv->gtt.base.inactive_list);
> + if (i915_gem_object_is_inactive(obj)) {
> + struct i915_vma *vma = i915_gem_obj_to_vma(obj,
> + &dev_priv->gtt.base);
> + if (vma)
> + list_move_tail(&vma->mm_list,
> + &dev_priv->gtt.base.inactive_list);
> +
> + }
>
> return 0;
> }
> @@ -3917,7 +3919,6 @@ unlock:
> void i915_gem_object_init(struct drm_i915_gem_object *obj,
> const struct drm_i915_gem_object_ops *ops)
> {
> - INIT_LIST_HEAD(&obj->mm_list);
> INIT_LIST_HEAD(&obj->global_list);
> INIT_LIST_HEAD(&obj->ring_list);
> INIT_LIST_HEAD(&obj->exec_list);
> @@ -4054,6 +4055,7 @@ struct i915_vma *i915_gem_vma_create(struct drm_i915_gem_object *obj,
> return ERR_PTR(-ENOMEM);
>
> INIT_LIST_HEAD(&vma->vma_link);
> + INIT_LIST_HEAD(&vma->mm_list);
> vma->vm = vm;
> vma->obj = obj;
>
> @@ -4063,6 +4065,7 @@ struct i915_vma *i915_gem_vma_create(struct drm_i915_gem_object *obj,
> void i915_gem_vma_destroy(struct i915_vma *vma)
> {
> list_del_init(&vma->vma_link);
> + list_del(&vma->mm_list);
> drm_mm_remove_node(&vma->node);
> kfree(vma);
> }
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index d1cb28c..88b0f52 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -436,7 +436,10 @@ static int do_switch(struct i915_hw_context *to)
> * MI_SET_CONTEXT instead of when the next seqno has completed.
> */
> if (from != NULL) {
> + struct drm_i915_private *dev_priv = from->obj->base.dev->dev_private;
> + struct i915_address_space *ggtt = &dev_priv->gtt.base;
> from->obj->base.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
> + list_move_tail(&i915_gem_obj_to_vma(from->obj, ggtt)->mm_list, &ggtt->active_list);

I don't really see a reason to add this here ... shouldn't move_to_active
take care of this? Obviously not in this patch here but later on when it's
converted over.

> i915_gem_object_move_to_active(from->obj, ring);
> /* As long as MI_SET_CONTEXT is serializing, ie. it flushes the
> * whole damn pipeline, we don't need to explicitly mark the
> diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
> index 61bf5e2..425939b 100644
> --- a/drivers/gpu/drm/i915/i915_gem_evict.c
> +++ b/drivers/gpu/drm/i915/i915_gem_evict.c
> @@ -87,8 +87,7 @@ i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
> drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
>
> /* First see if there is a large enough contiguous idle region... */
> - list_for_each_entry(obj, &vm->inactive_list, mm_list) {
> - struct i915_vma *vma = i915_gem_obj_to_vma(obj, vm);
> + list_for_each_entry(vma, &vm->inactive_list, mm_list) {
> if (mark_free(vma, &unwind_list))
> goto found;
> }
> @@ -97,8 +96,7 @@ i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
> goto none;
>
> /* Now merge in the soon-to-be-expired objects... */
> - list_for_each_entry(obj, &vm->active_list, mm_list) {
> - struct i915_vma *vma = i915_gem_obj_to_vma(obj, vm);
> + list_for_each_entry(vma, &vm->active_list, mm_list) {
> if (mark_free(vma, &unwind_list))
> goto found;
> }
> @@ -159,7 +157,7 @@ i915_gem_evict_everything(struct drm_device *dev)
> {
> drm_i915_private_t *dev_priv = dev->dev_private;
> struct i915_address_space *vm;
> - struct drm_i915_gem_object *obj, *next;
> + struct i915_vma *vma, *next;
> bool lists_empty = true;
> int ret;
>
> @@ -187,9 +185,9 @@ i915_gem_evict_everything(struct drm_device *dev)
>
> /* Having flushed everything, unbind() should never raise an error */
> list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
> - list_for_each_entry_safe(obj, next, &vm->inactive_list, mm_list)
> - if (obj->pin_count == 0)
> - WARN_ON(i915_vma_unbind(i915_gem_obj_to_vma(obj, vm)));
> + list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
> + if (vma->obj->pin_count == 0)
> + WARN_ON(i915_vma_unbind(vma));
> }
>
> return 0;
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 64dc6b5..0f21702 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -801,6 +801,8 @@ i915_gem_execbuffer_move_to_active(struct list_head *objects,
> obj->base.read_domains = obj->base.pending_read_domains;
> obj->fenced_gpu_access = obj->pending_fenced_gpu_access;
>
> + /* FIXME: This lookup gets fixed later <-- danvet */
> + list_move_tail(&i915_gem_obj_to_vma(obj, vm)->mm_list, &vm->active_list);

Ah, I guess the same comment applies to the lru frobbing in do_switch?

> i915_gem_object_move_to_active(obj, ring);
> if (obj->base.write_domain) {
> obj->dirty = 1;
> diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
> index 000ffbd..fa60103 100644
> --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
> +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
> @@ -419,7 +419,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
> obj->has_global_gtt_mapping = 1;
>
> list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
> - list_add_tail(&obj->mm_list, &ggtt->inactive_list);
> + list_add_tail(&vma->mm_list, &ggtt->inactive_list);
>
> return obj;
>
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index d970d84..9623a4e 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -556,11 +556,11 @@ static void capture_bo(struct drm_i915_error_buffer *err,
> static u32 capture_active_bo(struct drm_i915_error_buffer *err,
> int count, struct list_head *head)
> {
> - struct drm_i915_gem_object *obj;
> + struct i915_vma *vma;
> int i = 0;
>
> - list_for_each_entry(obj, head, mm_list) {
> - capture_bo(err++, obj);
> + list_for_each_entry(vma, head, mm_list) {
> + capture_bo(err++, vma->obj);
> if (++i == count)
> break;
> }
> @@ -622,7 +622,8 @@ static struct drm_i915_error_object *
> i915_error_first_batchbuffer(struct drm_i915_private *dev_priv,
> struct intel_ring_buffer *ring)
> {
> - struct i915_address_space *vm = &dev_priv->gtt.base;
> + struct i915_address_space *vm;
> + struct i915_vma *vma;
> struct drm_i915_gem_object *obj;
> u32 seqno;
>
> @@ -642,20 +643,23 @@ i915_error_first_batchbuffer(struct drm_i915_private *dev_priv,
> }
>
> seqno = ring->get_seqno(ring, false);
> - list_for_each_entry(obj, &vm->active_list, mm_list) {
> - if (obj->ring != ring)
> - continue;
> + list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
> + list_for_each_entry(vma, &vm->active_list, mm_list) {

We could instead loop over the bound list and check for ->active. But this
is ok, too albeit a bit convoluted imo.

> + obj = vma->obj;
> + if (obj->ring != ring)
> + continue;
>
> - if (i915_seqno_passed(seqno, obj->last_read_seqno))
> - continue;
> + if (i915_seqno_passed(seqno, obj->last_read_seqno))
> + continue;
>
> - if ((obj->base.read_domains & I915_GEM_DOMAIN_COMMAND) == 0)
> - continue;
> + if ((obj->base.read_domains & I915_GEM_DOMAIN_COMMAND) == 0)
> + continue;
>
> - /* We need to copy these to an anonymous buffer as the simplest
> - * method to avoid being overwritten by userspace.
> - */
> - return i915_error_object_create(dev_priv, obj);
> + /* We need to copy these to an anonymous buffer as the simplest
> + * method to avoid being overwritten by userspace.
> + */
> + return i915_error_object_create(dev_priv, obj);
> + }
> }
>
> return NULL;
> @@ -775,11 +779,12 @@ static void i915_gem_capture_buffers(struct drm_i915_private *dev_priv,
> struct drm_i915_error_state *error)
> {
> struct i915_address_space *vm = &dev_priv->gtt.base;
> + struct i915_vma *vma;
> struct drm_i915_gem_object *obj;
> int i;
>
> i = 0;
> - list_for_each_entry(obj, &vm->active_list, mm_list)
> + list_for_each_entry(vma, &vm->active_list, mm_list)
> i++;
> error->active_bo_count = i;
> list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list)
> --
> 1.8.3.4
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch