From: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
To: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: <intel-xe@lists.freedesktop.org>, <matthew.brost@intel.com>,
<stuart.summers@intel.com>
Subject: Re: [PATCH v4 05/11] drm/xe/multi_queue: Store primary LRC and position info in LRC
Date: Wed, 6 May 2026 18:39:31 -0700 [thread overview]
Message-ID: <afvtU7iUr4g3Y96-@nvishwa1-desk> (raw)
In-Reply-To: <afveRR-TNmiAdCFx@nvishwa1-desk>
On Wed, May 06, 2026 at 05:35:20PM -0700, Niranjana Vishwanathapura wrote:
>On Wed, May 06, 2026 at 03:35:06PM -0700, Umesh Nerlige Ramappa wrote:
>>For an LRC belonging to the secondary queue, in order to check if its
>>context group is active, we need to check the LRC of the primary queue.
>>In addition to that we want to compare the secondary queue position to
>>CSMQDEBUG register to check if the queue itself is active.
>>
>>To do so, store primary LRC and position information in the LRC.
>>
>>A note on references involved:
>>
>>- In general the Queue takes a ref on its LRC.
>>- In addition, for multi-queue,
>>a. Primary Queue takes a ref for each Secondary LRC.
>>b. Each Secondary Queue takes a ref to the Primary Queue
>>
>>In the current patch, each LRC in the queue group is storing a pointer
>>to primary LRC. Both primary and secondary LRCs are freed only when
>>primary queue is destroyed. At this time, all secondary queues are
>>already destroyed, so there is no one using secondary LRCs. We should be
>>good without taking any additional references.
>>
>>Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
>>---
>>v2:
>>- Store primary LRC instead of primary queue (Niranjana)
>>- Drop the valid flag and check if primary_lrc is NULL (Niranjana)
>>- Document/Revisit references (Matt/Umesh)
>>
>>v3:
>>- Drop the reference logic since it's not needed (Niranjana)
>>- Move lrc->multi_queue initialization to a later point (Niranjana)
>>
>>v4: (Niranjana)
>>- Set lrc[0].multi_queue.primary_lrc in xe_exec_queue_set_lrc
>>- Set lrc[0].multi_queue.pos in xe_exec_queue_group_add
>>- Include primary_context_desc and pos in snapshot
>>---
>>drivers/gpu/drm/xe/xe_exec_queue.c | 6 +++++-
>>drivers/gpu/drm/xe/xe_lrc.c | 14 ++++++++++++++
>>drivers/gpu/drm/xe/xe_lrc.h | 9 +++++++++
>>drivers/gpu/drm/xe/xe_lrc_types.h | 8 ++++++++
>>4 files changed, 36 insertions(+), 1 deletion(-)
>>
>>diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
>>index 62a75c8fe72f..4647a24dcffb 100644
>>--- a/drivers/gpu/drm/xe/xe_exec_queue.c
>>+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>>@@ -275,8 +275,11 @@ static void xe_exec_queue_set_lrc(struct xe_exec_queue *q, struct xe_lrc *lrc, u
>>{
>> xe_assert(gt_to_xe(q->gt), idx < q->width);
>>
>>- scoped_guard(spinlock, &q->lrc_lookup_lock)
>>+ scoped_guard(spinlock, &q->lrc_lookup_lock) {
>> q->lrc[idx] = lrc;
>>+ if (xe_exec_queue_is_multi_queue(q))
>>+ q->lrc[idx]->multi_queue.primary_lrc = q->multi_queue.group->primary->lrc[0];
>>+ }
>>}
>>
>>/**
>>@@ -907,6 +910,7 @@ static int xe_exec_queue_group_add(struct xe_device *xe, struct xe_exec_queue *q
>> }
>>
>> q->multi_queue.pos = pos;
>>+ q->lrc[0]->multi_queue.pos = pos;
>>
>> return 0;
>>}
>>diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
>>index b31525bd2a4c..3def999ce48a 100644
>>--- a/drivers/gpu/drm/xe/xe_lrc.c
>>+++ b/drivers/gpu/drm/xe/xe_lrc.c
>>@@ -2466,6 +2466,14 @@ struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc)
>> 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));
>>+ if (xe_lrc_is_multi_queue(lrc)) {
>>+ snapshot->multi_queue.primary_context_desc =
>>+ xe_lrc_ggtt_addr(lrc->multi_queue.primary_lrc);
>>+ snapshot->multi_queue.pos = lrc->multi_queue.pos;
>>+ } else {
>>+ snapshot->multi_queue.primary_context_desc = 0;
>>+ snapshot->multi_queue.pos = 0;
>>+ }
>> snapshot->ctx_job_timestamp = xe_lrc_ctx_job_timestamp(lrc);
>> return snapshot;
>>}
>>@@ -2521,6 +2529,12 @@ void xe_lrc_snapshot_print(struct xe_lrc_snapshot *snapshot, struct drm_printer
>> drm_printf(p, "\tTimestamp: 0x%016llx\n", snapshot->ctx_timestamp);
>> drm_printf(p, "\tTimestamp ms: %llu\n", snapshot->ctx_timestamp_ms);
>> drm_printf(p, "\tJob Timestamp: 0x%08x\n", snapshot->ctx_job_timestamp);
>>+ if (snapshot->multi_queue.primary_context_desc) {
>>+ drm_printf(p, "\tMulti queue primary Context Desc: 0x%08x\n",
>>+ snapshot->multi_queue.primary_context_desc);
>>+ drm_printf(p, "\tMulti queue position: %d\n",
>>+ snapshot->multi_queue.pos);
>
>What I am seeing is that LRC snapshot is printed along with exec_queue snapshot.
>The multi_queue position is already printed as part of exec_queue snapshot.
>Besides, as multi-queue primary guc id is also printed, one can easily get
>the primary context descriptor also. So, perhaps we can remove printing
>these info here as I am seeing LRC snapshot is always printed along with
>exec_queue snapshot. Sorry, for the confusion.
>
With that taken care of,
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>Niranjana
>
>>+ }
>>
>> if (!snapshot->lrc_snapshot)
>> return;
>>diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
>>index d280e6572398..d0deb916e4f1 100644
>>--- a/drivers/gpu/drm/xe/xe_lrc.h
>>+++ b/drivers/gpu/drm/xe/xe_lrc.h
>>@@ -40,6 +40,10 @@ struct xe_lrc_snapshot {
>> u64 ctx_timestamp;
>> u64 ctx_timestamp_ms;
>> u32 ctx_job_timestamp;
>>+ struct {
>>+ u32 primary_context_desc;
>>+ u8 pos;
>>+ } multi_queue;
>>};
>>
>>#define LRC_PPHWSP_FLUSH_INVAL_SCRATCH_ADDR (0x34 * 4)
>>@@ -91,6 +95,11 @@ static inline size_t xe_lrc_ring_size(void)
>> return SZ_16K;
>>}
>>
>>+static inline bool xe_lrc_is_multi_queue(struct xe_lrc *lrc)
>>+{
>>+ return lrc->multi_queue.primary_lrc;
>>+}
>>+
>>size_t xe_gt_lrc_hang_replay_size(struct xe_gt *gt, enum xe_engine_class class);
>>size_t xe_gt_lrc_size(struct xe_gt *gt, enum xe_engine_class class);
>>u32 xe_lrc_pphwsp_offset(struct xe_lrc *lrc);
>>diff --git a/drivers/gpu/drm/xe/xe_lrc_types.h b/drivers/gpu/drm/xe/xe_lrc_types.h
>>index 5a718f759ed6..0a5c13ec2ad7 100644
>>--- a/drivers/gpu/drm/xe/xe_lrc_types.h
>>+++ b/drivers/gpu/drm/xe/xe_lrc_types.h
>>@@ -63,6 +63,14 @@ struct xe_lrc {
>>
>> /** @ctx_timestamp: readout value of CTX_TIMESTAMP on last update */
>> u64 ctx_timestamp;
>>+
>>+ /** @multi_queue: Multi queue LRC related information */
>>+ struct {
>>+ /** @multi_queue.primary_lrc: Primary lrc of this multi-queue group*/
>>+ struct xe_lrc *primary_lrc;
>>+ /** @multi_queue.pos: Position of LRC within the multi-queue group */
>>+ u8 pos;
>>+ } multi_queue;
>>};
>>
>>struct xe_lrc_snapshot;
>>--
>>2.51.0
>>
next prev parent reply other threads:[~2026-05-07 1:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-06 22:35 [PATCH v4 00/11] Support run ticks for multi-queue use case Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 01/11] drm/xe/lrc: Use 64 bit ctx timestamp in the LRC snapshot Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 02/11] drm/xe: Add timestamp_ms to " Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 03/11] drm/xe/lrc: Refactor xe_lrc_timestamp to simplify logic Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 04/11] drm/xe/multi_queue: Refactor check for multi queue support for engine class Umesh Nerlige Ramappa
2026-05-07 0:28 ` Niranjana Vishwanathapura
2026-05-06 22:35 ` [PATCH v4 05/11] drm/xe/multi_queue: Store primary LRC and position info in LRC Umesh Nerlige Ramappa
2026-05-07 0:35 ` Niranjana Vishwanathapura
2026-05-07 1:39 ` Niranjana Vishwanathapura [this message]
2026-05-06 22:35 ` [PATCH v4 06/11] drm/xe/multi_queue: Add helpers to access CS QUEUE TIMESTAMP from lrc Umesh Nerlige Ramappa
2026-05-07 0:29 ` Niranjana Vishwanathapura
2026-05-06 22:35 ` [PATCH v4 07/11] drm/xe/lrc: Refactor out engine id to hwe conversion Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 08/11] drm/xe/multi_queue: Capture queue run times for active queues Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 09/11] drm/xe/multi_queue: Add trace event for the multi queue timestamp Umesh Nerlige Ramappa
2026-05-07 0:28 ` Niranjana Vishwanathapura
2026-05-06 22:35 ` [PATCH v4 10/11] drm/xe/multi_queue: Use QUEUE_TIMESTAMP as job timestamp for multi-queue Umesh Nerlige Ramappa
2026-05-06 22:35 ` [PATCH v4 11/11] drm/xe/multi_queue: Whitelist QUEUE_TIMESTAMP register Umesh Nerlige Ramappa
2026-05-06 22:41 ` ✗ CI.checkpatch: warning for Support run ticks for multi-queue use case (rev4) Patchwork
2026-05-06 22:42 ` ✓ CI.KUnit: success " Patchwork
2026-05-06 23:44 ` ✓ Xe.CI.BAT: " Patchwork
2026-05-07 0:44 ` ✗ Xe.CI.FULL: failure " Patchwork
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