Re: [PATCH 2/2] drm/i915: Print captured bo for all VM in error state

Ben Widawsky
2014-01-10T19:59:19Z

On Thu, Jan 09, 2014 at 10:57:23PM +0000, Chris Wilson wrote:
> The current error state harks back to the era of just a single VM. For
> full-ppgtt, we capture every bo on every VM. It behoves us to then print
> every bo for every VM, which we currently fail to do and so miss vital
> information in the error state.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

I'm somewhat disappointed with myself since I know I had a lot of this
at one point in time. Thanks for finding/fixing it.

> ---
> drivers/gpu/drm/i915/i915_drv.h | 4 +++
> drivers/gpu/drm/i915/i915_gpu_error.c | 66 ++++++++++++++++++++++++++---------
> 2 files changed, 54 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8f0ef8645ea9..673aaee527eb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -331,6 +331,7 @@ struct drm_i915_error_state {
> u32 faddr[I915_NUM_RINGS];
> u64 fence[I915_MAX_NUM_FENCES];
> struct timeval time;
> +
> struct drm_i915_error_ring {
> struct drm_i915_error_object {
> int page_count;
> @@ -344,6 +345,7 @@ struct drm_i915_error_state {
> } *requests;
> int num_requests;
> } ring[I915_NUM_RINGS];
> +

Not sure if Daniel cares about the whitespace insertions. I do not.

> struct drm_i915_error_buffer {
> u32 size;
> u32 name;
> @@ -361,6 +363,8 @@ struct drm_i915_error_state {
> u32 cache_level:3;
> } **active_bo, **pinned_bo;
> u32 *active_bo_count, *pinned_bo_count;
> + u32 vm_count;
> +

One patch which I never submitted held vm_count in dev_priv. I found it
useful at one time, but I apparently forgot about it.

> struct intel_overlay_error_state *overlay;
> struct intel_display_error_state *display;
> int hangcheck_score[I915_NUM_RINGS];
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index cce9f559e3d7..b7ead8ce6628 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -188,10 +188,10 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
> struct drm_i915_error_buffer *err,
> int count)
> {
> - err_printf(m, "%s [%d]:\n", name, count);
> + err_printf(m, " %s [%d]:\n", name, count);
>
> while (count--) {
> - err_printf(m, " %08x %8u %02x %02x %x %x",
> + err_printf(m, " %08x %8u %02x %02x %x %x",
> err->gtt_offset,
> err->size,
> err->read_domains,
> @@ -332,15 +332,17 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
> for_each_ring(ring, dev_priv, i)
> i915_ring_error_state(m, dev, error, i);
>
> - if (error->active_bo)
> + for (i = 0; i < error->vm_count; i++) {
> + err_printf(m, "vm[%d]\n", i);
> +
> print_error_buffers(m, "Active",
> - error->active_bo[0],
> - error->active_bo_count[0]);
> + error->active_bo[i],
> + error->active_bo_count[i]);
>
> - if (error->pinned_bo)
> print_error_buffers(m, "Pinned",
> - error->pinned_bo[0],
> - error->pinned_bo_count[0]);
> + error->pinned_bo[i],
> + error->pinned_bo_count[i]);
> + }
>
> for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
> struct drm_i915_error_object *obj;
> @@ -606,13 +608,23 @@ static u32 capture_active_bo(struct drm_i915_error_buffer *err,
> }
>
> static u32 capture_pinned_bo(struct drm_i915_error_buffer *err,
> - int count, struct list_head *head)
> + int count, struct list_head *head,
> + struct i915_address_space *vm)
> {
> struct drm_i915_gem_object *obj;
> int i = 0;
>
> list_for_each_entry(obj, head, global_list) {
> - if (!i915_gem_obj_is_pinned(obj))
> + struct i915_vma *vma;
> + bool bound = false;
> +
> + list_for_each_entry(vma, &obj->vma_list, vma_link)
> + if (vma->vm == vm && vma->pin_count > 0) {
> + bound = true;
> + break;
> + }
> +
> + if (!bound)
> continue;
>
> capture_bo(err++, obj);
> @@ -876,9 +888,14 @@ static void i915_gem_capture_vm(struct drm_i915_private *dev_priv,
> list_for_each_entry(vma, &vm->active_list, mm_list)
> i++;
> error->active_bo_count[ndx] = i;
> - list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list)
> - if (i915_gem_obj_is_pinned(obj))
> - i++;
> +
> + list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
> + list_for_each_entry(vma, &obj->vma_list, vma_link)
> + if (vma->vm == vm && vma->pin_count > 0) {
> + i++;
> + break;
> + }
> + }

FWIW, the old code predated per VMA pin counts.

> error->pinned_bo_count[ndx] = i - error->active_bo_count[ndx];
>
> if (i) {
> @@ -897,7 +914,7 @@ static void i915_gem_capture_vm(struct drm_i915_private *dev_priv,
> error->pinned_bo_count[ndx] =
> capture_pinned_bo(pinned_bo,
> error->pinned_bo_count[ndx],
> - &dev_priv->mm.bound_list);
> + &dev_priv->mm.bound_list, vm);

With my original patches which I obviously didn't submit (see top), I
made capture_pinned_vma() and capture_active_vma(). I think it fits
better with Daniel's ideal of killing <obj, vm>

> error->active_bo[ndx] = active_bo;
> error->pinned_bo[ndx] = pinned_bo;
> }
> @@ -918,8 +935,25 @@ static void i915_gem_capture_buffers(struct drm_i915_private *dev_priv,
> error->pinned_bo_count = kcalloc(cnt, sizeof(*error->pinned_bo_count),
> GFP_ATOMIC);
>
> - list_for_each_entry(vm, &dev_priv->vm_list, global_link)
> - i915_gem_capture_vm(dev_priv, error, vm, i++);
> + if (error->active_bo == NULL ||
> + error->pinned_bo == NULL ||
> + error->active_bo_count == NULL ||
> + error->pinned_bo_count == NULL) {
> + kfree(error->active_bo);
> + kfree(error->active_bo_count);
> + kfree(error->pinned_bo);
> + kfree(error->pinned_bo_count);
> +
> + error->active_bo = NULL;
> + error->active_bo_count = NULL;
> + error->pinned_bo = NULL;
> + error->pinned_bo_count = NULL;

This is really a separate fix/patch.

> + } else {
> + list_for_each_entry(vm, &dev_priv->vm_list, global_link)
> + i915_gem_capture_vm(dev_priv, error, vm, i++);
> +
> + error->vm_count = cnt;
> + }

One other change which I apparently never pushed was to try to identify
the guilty context/VM (instead of the global as you do for patch 1 of
the series). that way foo_bo[0] was always the interesting one.

> }
>
> /**
> --
> 1.8.5.2

Both patches are
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

I will gladly re-review if you make any of my suggested changes.

--
Ben Widawsky, Intel Open Source Technology Center