El lun, 21-09-2026 a las 18:24 -0300, Maíra Canal escribió:
> A global perfmon counts concurrent activity from every job, so no
> dependency is added while one is set. Skip the accumulator for the
> jobs
> carrying no perfmon while a global perfmon is enabled, which is every
> job
> in the common case.
>
> Jobs carrying their own perfmon stay tracked. The global perfmon may
> be
> cleared before such a job runs, and the next job carrying a perfmon
> has
> to wait for it, otherwise both are in flight at once and only one
> gets
> programmed in the HW.
>
> Signed-off-by: Maíra Canal <[email protected]>
> ---
> drivers/gpu/drm/v3d/v3d_submit.c | 18 ++++++++----------
> 1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_submit.c
> b/drivers/gpu/drm/v3d/v3d_submit.c
> index bc3c43fd4fd9..7548faab67ba 100644
> --- a/drivers/gpu/drm/v3d/v3d_submit.c
> +++ b/drivers/gpu/drm/v3d/v3d_submit.c
> @@ -359,15 +359,15 @@ v3d_attach_perfmon_to_jobs(struct v3d_submit
> *submit, u32 perfmon_id)
> * track concurrent activity from all jobs.
> *
> * Keeping track of the in-flight jobs costs a fence merge per job,
> so it is
> - * only done while at least one perfmon is alive. Jobs submitted
> while no
> - * perfmon exists go untracked and may overlap the first measured
> job.
> + * only done while at least one perfmon is alive, and is skipped for
> the jobs
> + * carrying no perfmon while a global perfmon is set. Jobs submitted
> while
> + * tracking is off go untracked and may overlap the first measured
> job.
> */
> static int
> v3d_serialize_for_perfmon(struct v3d_job *job)
> {
> struct v3d_dev *v3d = job->v3d;
> struct dma_fence *merged;
> - bool is_global_perfmon;
> int ret;
>
> lockdep_assert_held(&v3d->sched_lock);
> @@ -375,11 +375,10 @@ v3d_serialize_for_perfmon(struct v3d_job *job)
> if (!atomic_read(&v3d->perfmon_state.nperfmons))
> return 0;
>
> - scoped_guard(spinlock_irqsave, &v3d->perfmon_state.lock)
> - is_global_perfmon = !!v3d->global_perfmon;
> -
> - if (is_global_perfmon)
> - goto publish;
> + scoped_guard(spinlock_irqsave, &v3d->perfmon_state.lock) {
> + if (!job->perfmon && v3d->global_perfmon)
> + return 0;
Same suggestion as in previous patch about updating docs for
last_hw_fence. This change means we don't update it in this case
either, to we should probably reflect that the field documentation.
> + }
>
> if (job->perfmon) {
> for (enum v3d_queue q = 0; q < V3D_MAX_QUEUES; q++)
> {
> @@ -400,7 +399,6 @@ v3d_serialize_for_perfmon(struct v3d_job *job)
> return ret;
> }
>
> -publish:
> /*
> * Accumulate every in-flight job on this queue into one
> merged fence.
> * A HW queue is fed by several scheduler entities (one per-
> fd), so jobs
> @@ -414,7 +412,7 @@ v3d_serialize_for_perfmon(struct v3d_job *job)
> dma_fence_put(v3d->perfmon_state.last_hw_fence[job->queue]);
> v3d->perfmon_state.last_hw_fence[job->queue] = merged;
>
> - if (job->perfmon && !is_global_perfmon) {
> + if (job->perfmon) {
> dma_fence_put(v3d->perfmon_state.fence);
> v3d->perfmon_state.fence = dma_fence_get(job-
> >done_fence);
> }
>
