On Mon, Feb 10, 2025 at 07:35:44PM +0000, Jonathan Cavitt wrote:
> Add counters to all engines that count the number of pagefaults and
> engine resets that have been triggered on them. Report these values
> during an engine reset.
>
I'm not opposed to adding stats for engines, but if we do, I think it
should be done in a generic way. See xe_gt_stats* for an example—that
is, do not use specific variables for counters; instead, use an array
indexed by an enum. I'd also probably wire to debugfs while here using
the aforementioned example as a template.
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> CC: Tomasz Mistat <tomasz.mistat@xxxxxxxxx>
> CC: Ayaz A Siddiqui <ayaz.siddiqui@xxxxxxxxx>
> CC: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
> ---
> drivers/gpu/drm/xe/xe_gt_pagefault.c | 6 ++++++
> drivers/gpu/drm/xe/xe_guc_submit.c | 9 +++++++--
> drivers/gpu/drm/xe/xe_hw_engine.c | 3 +++
> drivers/gpu/drm/xe/xe_hw_engine_types.h | 4 ++++
> 4 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> index 46701ca11ce0..04e973b20019 100644
> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> @@ -130,6 +130,7 @@ static int handle_vma_pagefault(struct xe_gt *gt, struct pagefault *pf,
> {
> struct xe_vm *vm = xe_vma_vm(vma);
> struct xe_tile *tile = gt_to_tile(gt);
> + struct xe_hw_engine *hwe = NULL;
> struct drm_exec exec;
> struct dma_fence *fence;
> ktime_t end = 0;
> @@ -140,6 +141,11 @@ static int handle_vma_pagefault(struct xe_gt *gt, struct pagefault *pf,
> xe_gt_stats_incr(gt, XE_GT_STATS_ID_VMA_PAGEFAULT_BYTES, xe_vma_size(vma));
>
> trace_xe_vma_pagefault(vma);
> +
> + hwe = xe_gt_hw_engine(gt, pf->engine_class, pf->engine_instance, false);
> + if (hwe)
> + atomic_inc(&hwe->pagefault_count);
> +
Page faults are a critical path so anything that is debug related (e.g.
stats) likely should compile out in non-debug builds.
> atomic = access_is_atomic(pf->access_type);
>
> /* Check if VMA is valid */
> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> index 913c74d6e2ae..6f5d74340319 100644
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@ -1972,6 +1972,7 @@ int xe_guc_exec_queue_reset_handler(struct xe_guc *guc, u32 *msg, u32 len)
> {
> struct xe_gt *gt = guc_to_gt(guc);
> struct xe_exec_queue *q;
> + struct xe_hw_engine *hwe;
> u32 guc_id;
>
> if (unlikely(len < 1))
> @@ -1983,8 +1984,12 @@ int xe_guc_exec_queue_reset_handler(struct xe_guc *guc, u32 *msg, u32 len)
> if (unlikely(!q))
> return -EPROTO;
>
> - xe_gt_info(gt, "Engine reset: engine_class=%s, logical_mask: 0x%x, guc_id=%d",
> - xe_hw_engine_class_to_str(q->class), q->logical_mask, guc_id);
> + hwe = q->hwe;
> + atomic_inc(&hwe->reset_count);
> +
> + xe_gt_info(gt, "Engine reset: engine_class=%s, logical_mask: 0x%x, guc_id=%d, pagefault_count=%u, reset_count=%u",
> + xe_hw_engine_class_to_str(q->class), q->logical_mask, guc_id,
> + atomic_read(&hwe->pagefault_count), atomic_read(&hwe->reset_count));
Can you explain why this information is helpful? A better option than
dmesg might be a devcoredump too. I'll need a little more background
here I guess.
Matt
>
> trace_xe_exec_queue_reset(q);
>
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
> index fc447751fe78..0be6c38fe2a4 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine.c
> @@ -516,6 +516,9 @@ static void hw_engine_init_early(struct xe_gt *gt, struct xe_hw_engine *hwe,
> hwe->fence_irq = >->fence_irq[info->class];
> hwe->engine_id = id;
>
> + atomic_set(&hwe->pagefault_count, 0);
> + atomic_set(&hwe->reset_count, 0);
> +
> hwe->eclass = >->eclass[hwe->class];
> if (!hwe->eclass->sched_props.job_timeout_ms) {
> hwe->eclass->sched_props.job_timeout_ms = 5 * 1000;
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine_types.h b/drivers/gpu/drm/xe/xe_hw_engine_types.h
> index e4191a7a2c31..635dc3da6523 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine_types.h
> +++ b/drivers/gpu/drm/xe/xe_hw_engine_types.h
> @@ -150,6 +150,10 @@ struct xe_hw_engine {
> struct xe_oa_unit *oa_unit;
> /** @hw_engine_group: the group of hw engines this one belongs to */
> struct xe_hw_engine_group *hw_engine_group;
> + /** @pagefault_count: number of pagefaults associated with this engine */
> + atomic_t pagefault_count;
> + /** @reset_count: number of engine resets associated with this engine */
> + atomic_t reset_count;
> };
>
> enum xe_hw_engine_snapshot_source_id {
> --
> 2.43.0
>
