drivers/gpu/drm/panthor/panthor_drv.c | 2 +- drivers/gpu/drm/panthor/panthor_sched.c | 32 +++++++++++++++++-------- drivers/gpu/drm/panthor/panthor_sched.h | 3 ++- 3 files changed, 25 insertions(+), 12 deletions(-)
Userspace relies on the ring field of gpu_scheduler tracepoints to
identify a drm_gpu_scheduler. The value of the ring field is taken from
sched->name.
Because we typically have multiple schedulers running in parallel in
each process, assign unique names to schedulers such that userspace can
distinguish them.
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
---
v2:
- include drm_client_id in the name to be truly unique
- remove unnecessary NULL in drm_sched_init_args initialization
- reformat to column width 100
---
drivers/gpu/drm/panthor/panthor_drv.c | 2 +-
drivers/gpu/drm/panthor/panthor_sched.c | 32 +++++++++++++++++--------
drivers/gpu/drm/panthor/panthor_sched.h | 3 ++-
3 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 9256806eb6623..be962b1387f03 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1105,7 +1105,7 @@ static int panthor_ioctl_group_create(struct drm_device *ddev, void *data,
if (ret)
goto out;
- ret = panthor_group_create(pfile, args, queue_args);
+ ret = panthor_group_create(pfile, args, queue_args, file->client_id);
if (ret < 0)
goto out;
args->group_handle = ret;
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index ba5dc3e443d9c..62f17476e5852 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -360,6 +360,9 @@ struct panthor_queue {
/** @entity: DRM scheduling entity used for this queue. */
struct drm_sched_entity entity;
+ /** @name: DRM scheduler name for this queue. */
+ char name[32];
+
/**
* @remaining_time: Time remaining before the job timeout expires.
*
@@ -3308,9 +3311,10 @@ static u32 calc_profiling_ringbuf_num_slots(struct panthor_device *ptdev,
static struct panthor_queue *
group_create_queue(struct panthor_group *group,
- const struct drm_panthor_queue_create *args)
+ const struct drm_panthor_queue_create *args,
+ u64 drm_client_id, u32 gid, u32 qid)
{
- const struct drm_sched_init_args sched_args = {
+ struct drm_sched_init_args sched_args = {
.ops = &panthor_queue_sched_ops,
.submit_wq = group->ptdev->scheduler->wq,
.num_rqs = 1,
@@ -3323,7 +3327,6 @@ group_create_queue(struct panthor_group *group,
.credit_limit = args->ringbuf_size / sizeof(u64),
.timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
.timeout_wq = group->ptdev->reset.wq,
- .name = "panthor-queue",
.dev = group->ptdev->base.dev,
};
struct drm_gpu_scheduler *drm_sched;
@@ -3398,6 +3401,11 @@ group_create_queue(struct panthor_group *group,
if (ret)
goto err_free_queue;
+ /* assign a unique name */
+ snprintf(queue->name, sizeof(queue->name), "panthor-queue-%llu-%u-%u",
+ drm_client_id, gid, qid);
+ sched_args.name = queue->name;
+
ret = drm_sched_init(&queue->scheduler, &sched_args);
if (ret)
goto err_free_queue;
@@ -3447,7 +3455,8 @@ static void add_group_kbo_sizes(struct panthor_device *ptdev,
int panthor_group_create(struct panthor_file *pfile,
const struct drm_panthor_group_create *group_args,
- const struct drm_panthor_queue_create *queue_args)
+ const struct drm_panthor_queue_create *queue_args,
+ u64 drm_client_id)
{
struct panthor_device *ptdev = pfile->ptdev;
struct panthor_group_pool *gpool = pfile->groups;
@@ -3540,12 +3549,16 @@ int panthor_group_create(struct panthor_file *pfile,
memset(group->syncobjs->kmap, 0,
group_args->queues.count * sizeof(struct panthor_syncobj_64b));
+ ret = xa_alloc(&gpool->xa, &gid, group, XA_LIMIT(1, MAX_GROUPS_PER_POOL), GFP_KERNEL);
+ if (ret)
+ goto err_put_group;
+
for (i = 0; i < group_args->queues.count; i++) {
- group->queues[i] = group_create_queue(group, &queue_args[i]);
+ group->queues[i] = group_create_queue(group, &queue_args[i], drm_client_id, gid, i);
if (IS_ERR(group->queues[i])) {
ret = PTR_ERR(group->queues[i]);
group->queues[i] = NULL;
- goto err_put_group;
+ goto err_erase_gid;
}
group->queue_count++;
@@ -3553,10 +3566,6 @@ int panthor_group_create(struct panthor_file *pfile,
group->idle_queues = GENMASK(group->queue_count - 1, 0);
- ret = xa_alloc(&gpool->xa, &gid, group, XA_LIMIT(1, MAX_GROUPS_PER_POOL), GFP_KERNEL);
- if (ret)
- goto err_put_group;
-
mutex_lock(&sched->reset.lock);
if (atomic_read(&sched->reset.in_progress)) {
panthor_group_stop(group);
@@ -3575,6 +3584,9 @@ int panthor_group_create(struct panthor_file *pfile,
return gid;
+err_erase_gid:
+ xa_erase(&gpool->xa, gid);
+
err_put_group:
group_put(group);
return ret;
diff --git a/drivers/gpu/drm/panthor/panthor_sched.h b/drivers/gpu/drm/panthor/panthor_sched.h
index 742b0b4ff3a3c..f4a475aa34c0a 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.h
+++ b/drivers/gpu/drm/panthor/panthor_sched.h
@@ -21,7 +21,8 @@ struct panthor_job;
int panthor_group_create(struct panthor_file *pfile,
const struct drm_panthor_group_create *group_args,
- const struct drm_panthor_queue_create *queue_args);
+ const struct drm_panthor_queue_create *queue_args,
+ u64 drm_client_id);
int panthor_group_destroy(struct panthor_file *pfile, u32 group_handle);
int panthor_group_get_state(struct panthor_file *pfile,
struct drm_panthor_group_get_state *get_state);
--
2.51.0.318.gd7df087d1a-googOn Fri, 29 Aug 2025 16:02:50 -0700
Chia-I Wu <olvaffe@gmail.com> wrote:
> Userspace relies on the ring field of gpu_scheduler tracepoints to
> identify a drm_gpu_scheduler. The value of the ring field is taken from
> sched->name.
>
> Because we typically have multiple schedulers running in parallel in
> each process, assign unique names to schedulers such that userspace can
> distinguish them.
>
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
>
> ---
>
> v2:
> - include drm_client_id in the name to be truly unique
> - remove unnecessary NULL in drm_sched_init_args initialization
> - reformat to column width 100
> ---
> drivers/gpu/drm/panthor/panthor_drv.c | 2 +-
> drivers/gpu/drm/panthor/panthor_sched.c | 32 +++++++++++++++++--------
> drivers/gpu/drm/panthor/panthor_sched.h | 3 ++-
> 3 files changed, 25 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> index 9256806eb6623..be962b1387f03 100644
> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> @@ -1105,7 +1105,7 @@ static int panthor_ioctl_group_create(struct drm_device *ddev, void *data,
> if (ret)
> goto out;
>
> - ret = panthor_group_create(pfile, args, queue_args);
> + ret = panthor_group_create(pfile, args, queue_args, file->client_id);
Hm, maybe it's time we start passing drm_file instead of panthor_file
to limit the number of arguments, but I guess this can be done in a
follow-up patch.
> if (ret < 0)
> goto out;
> args->group_handle = ret;
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index ba5dc3e443d9c..62f17476e5852 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -360,6 +360,9 @@ struct panthor_queue {
> /** @entity: DRM scheduling entity used for this queue. */
> struct drm_sched_entity entity;
>
> + /** @name: DRM scheduler name for this queue. */
> + char name[32];
The base string ("panthor-queue---") is already 16 characters. You then
have a group ID that's below 128 IIRC, and a queue ID that's no more
than 15, so that's 5 more chars. This leaves you 10 chars for the
client ID (theoretically a 64-bit integer). I know the logic is sane
because you truncate the string, but I'm wondering if we shouldn't make
this string bigger to cover the theoretical max client_id, or simply
dynamically allocate it (kasprintf()), so we don't have to think about
it if we end up adding more stuff to the string.
> +
> /**
> * @remaining_time: Time remaining before the job timeout expires.
> *
> @@ -3308,9 +3311,10 @@ static u32 calc_profiling_ringbuf_num_slots(struct panthor_device *ptdev,
>
> static struct panthor_queue *
> group_create_queue(struct panthor_group *group,
> - const struct drm_panthor_queue_create *args)
> + const struct drm_panthor_queue_create *args,
> + u64 drm_client_id, u32 gid, u32 qid)
> {
> - const struct drm_sched_init_args sched_args = {
> + struct drm_sched_init_args sched_args = {
> .ops = &panthor_queue_sched_ops,
> .submit_wq = group->ptdev->scheduler->wq,
> .num_rqs = 1,
> @@ -3323,7 +3327,6 @@ group_create_queue(struct panthor_group *group,
> .credit_limit = args->ringbuf_size / sizeof(u64),
> .timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
> .timeout_wq = group->ptdev->reset.wq,
> - .name = "panthor-queue",
> .dev = group->ptdev->base.dev,
> };
> struct drm_gpu_scheduler *drm_sched;
> @@ -3398,6 +3401,11 @@ group_create_queue(struct panthor_group *group,
> if (ret)
> goto err_free_queue;
>
> + /* assign a unique name */
> + snprintf(queue->name, sizeof(queue->name), "panthor-queue-%llu-%u-%u",
> + drm_client_id, gid, qid);
> + sched_args.name = queue->name;
> +
> ret = drm_sched_init(&queue->scheduler, &sched_args);
> if (ret)
> goto err_free_queue;
> @@ -3447,7 +3455,8 @@ static void add_group_kbo_sizes(struct panthor_device *ptdev,
>
> int panthor_group_create(struct panthor_file *pfile,
> const struct drm_panthor_group_create *group_args,
> - const struct drm_panthor_queue_create *queue_args)
> + const struct drm_panthor_queue_create *queue_args,
> + u64 drm_client_id)
> {
> struct panthor_device *ptdev = pfile->ptdev;
> struct panthor_group_pool *gpool = pfile->groups;
> @@ -3540,12 +3549,16 @@ int panthor_group_create(struct panthor_file *pfile,
> memset(group->syncobjs->kmap, 0,
> group_args->queues.count * sizeof(struct panthor_syncobj_64b));
>
> + ret = xa_alloc(&gpool->xa, &gid, group, XA_LIMIT(1, MAX_GROUPS_PER_POOL), GFP_KERNEL);
> + if (ret)
> + goto err_put_group;
> +
> for (i = 0; i < group_args->queues.count; i++) {
> - group->queues[i] = group_create_queue(group, &queue_args[i]);
> + group->queues[i] = group_create_queue(group, &queue_args[i], drm_client_id, gid, i);
> if (IS_ERR(group->queues[i])) {
> ret = PTR_ERR(group->queues[i]);
> group->queues[i] = NULL;
> - goto err_put_group;
> + goto err_erase_gid;
> }
>
> group->queue_count++;
> @@ -3553,10 +3566,6 @@ int panthor_group_create(struct panthor_file *pfile,
>
> group->idle_queues = GENMASK(group->queue_count - 1, 0);
>
> - ret = xa_alloc(&gpool->xa, &gid, group, XA_LIMIT(1, MAX_GROUPS_PER_POOL), GFP_KERNEL);
> - if (ret)
> - goto err_put_group;
> -
> mutex_lock(&sched->reset.lock);
> if (atomic_read(&sched->reset.in_progress)) {
> panthor_group_stop(group);
> @@ -3575,6 +3584,9 @@ int panthor_group_create(struct panthor_file *pfile,
>
> return gid;
>
> +err_erase_gid:
> + xa_erase(&gpool->xa, gid);
> +
> err_put_group:
> group_put(group);
> return ret;
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.h b/drivers/gpu/drm/panthor/panthor_sched.h
> index 742b0b4ff3a3c..f4a475aa34c0a 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.h
> +++ b/drivers/gpu/drm/panthor/panthor_sched.h
> @@ -21,7 +21,8 @@ struct panthor_job;
>
> int panthor_group_create(struct panthor_file *pfile,
> const struct drm_panthor_group_create *group_args,
> - const struct drm_panthor_queue_create *queue_args);
> + const struct drm_panthor_queue_create *queue_args,
> + u64 drm_client_id);
> int panthor_group_destroy(struct panthor_file *pfile, u32 group_handle);
> int panthor_group_get_state(struct panthor_file *pfile,
> struct drm_panthor_group_get_state *get_state);
On Mon, Sep 1, 2025 at 12:27 AM Boris Brezillon
<boris.brezillon@collabora.com> wrote:
<snipped>
> > diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> > index ba5dc3e443d9c..62f17476e5852 100644
> > --- a/drivers/gpu/drm/panthor/panthor_sched.c
> > +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> > @@ -360,6 +360,9 @@ struct panthor_queue {
> > /** @entity: DRM scheduling entity used for this queue. */
> > struct drm_sched_entity entity;
> >
> > + /** @name: DRM scheduler name for this queue. */
> > + char name[32];
>
> The base string ("panthor-queue---") is already 16 characters. You then
> have a group ID that's below 128 IIRC, and a queue ID that's no more
> than 15, so that's 5 more chars. This leaves you 10 chars for the
> client ID (theoretically a 64-bit integer). I know the logic is sane
> because you truncate the string, but I'm wondering if we shouldn't make
> this string bigger to cover the theoretical max client_id, or simply
> dynamically allocate it (kasprintf()), so we don't have to think about
> it if we end up adding more stuff to the string.
It seems we don't validate queue count. Sending
https://lore.kernel.org/lkml/20250902192001.409738-1-olvaffe@gmail.com/
for that.
On a user device that opens the render node once per second, 10 chars
are good for 317 years. It lasts significantly shorter on a test
device, but the uptime is also significantly shorter on such a device
(hopefully).
But kasprintf should be harmless here. I can certainly switch to it.
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