Re: [PATCH v2 2/9] drm/xe: Add timestamp_ms to LRC snapshot

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

On Fri, May 01, 2026 at 05:53:35PM -0700, Umesh Nerlige Ramappa wrote:
>From: Matthew Brost <matthew.brost@intel.com>
>
>Add a timestamp in milliseconds to the LRC snapshot to make it easier to
>reason about how long the LRC has been running and the average duration
>of each job.
>
>Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>---
> drivers/gpu/drm/xe/xe_lrc.c | 4 ++++
> drivers/gpu/drm/xe/xe_lrc.h | 1 +
> 2 files changed, 5 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
>index 98dc4d0eb61b..d85c712d106b 100644
>--- a/drivers/gpu/drm/xe/xe_lrc.c
>+++ b/drivers/gpu/drm/xe/xe_lrc.c
>@@ -23,6 +23,7 @@
> #include "xe_drm_client.h"
> #include "xe_exec_queue_types.h"
> #include "xe_gt.h"
>+#include "xe_gt_clock.h"
> #include "xe_gt_printk.h"
> #include "xe_hw_fence.h"
> #include "xe_map.h"
>@@ -2476,6 +2477,8 @@ struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc)
> 	snapshot->replay_size = lrc->replay_size;
> 	snapshot->lrc_snapshot = NULL;
> 	snapshot->ctx_timestamp = xe_lrc_ctx_timestamp(lrc);
>+	snapshot->ctx_timestamp_ms =
>+		xe_gt_clock_interval_to_ms(lrc->gt, xe_lrc_ctx_timestamp(lrc));
> 	snapshot->ctx_job_timestamp = xe_lrc_ctx_job_timestamp(lrc);
> 	return snapshot;
> }
>@@ -2529,6 +2532,7 @@ void xe_lrc_snapshot_print(struct xe_lrc_snapshot *snapshot, struct drm_printer
> 	drm_printf(p, "\tStart seqno: (memory) %d\n", snapshot->start_seqno);
> 	drm_printf(p, "\tSeqno: (memory) %d\n", snapshot->seqno);
> 	drm_printf(p, "\tTimestamp: 0x%016llx\n", snapshot->ctx_timestamp);
>+	drm_printf(p, "\tTimestamp ms: %llu\n", snapshot->ctx_timestamp_ms);

Do we need a separate field for this? Maybe add it in a single line?
drm_printf(p, "\tTimestamp: 0x%016llx (%llums)\n", snapshot->ctx_timestamp, snapshot->ctx_timestamp_ms);

I am hoping we don't have any script that is using these capture dumps which we might be breaking here.

> 	drm_printf(p, "\tJob Timestamp: 0x%08x\n", snapshot->ctx_job_timestamp);
>
> 	if (!snapshot->lrc_snapshot)
>diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
>index 62beaffba0af..97aef0327fc8 100644
>--- a/drivers/gpu/drm/xe/xe_lrc.h
>+++ b/drivers/gpu/drm/xe/xe_lrc.h
>@@ -39,6 +39,7 @@ struct xe_lrc_snapshot {
> 	u32 seqno;
> 	u64 ctx_timestamp;
> 	u32 ctx_job_timestamp;
>+	u64 ctx_timestamp_ms;

NIT...may be put ctx_timestamp_ms right after ctx_timestamp?
That way, we won't be adding a u32 in between two u64s.

Niranjana

> };
>
> #define LRC_PPHWSP_FLUSH_INVAL_SCRATCH_ADDR (0x34 * 4)
>-- 
>2.43.0
>