On 30/07/2026 12:45, Nicolas Frattaroli wrote: > Add two new event tracepoints: gpu_cache_flush_start to be emitted after > acquiring the flush mutex and reqs spinlock, and gpu_cache_flush_end to > be emitted when leaving the function. > > This allows debugging the duration a flush takes irrespective of initial > function entry lock contention by subtracting the start tracepoint's > timestamp from the end tracepoint timestamp, and additionally contains > information such as which caches were flushed. > > Signed-off-by: Nicolas Frattaroli <[email protected]>
Reviewed-by: Steven Price <[email protected]> Thanks, Steve > --- > drivers/gpu/drm/panthor/panthor_gpu.c | 3 ++ > drivers/gpu/drm/panthor/panthor_trace.h | 49 > +++++++++++++++++++++++++++++++++ > 2 files changed, 52 insertions(+) > > diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c > b/drivers/gpu/drm/panthor/panthor_gpu.c > index f015bde80abf..a25955ad668b 100644 > --- a/drivers/gpu/drm/panthor/panthor_gpu.c > +++ b/drivers/gpu/drm/panthor/panthor_gpu.c > @@ -336,6 +336,7 @@ int panthor_gpu_flush_caches(struct panthor_device *ptdev, > guard(mutex)(&ptdev->gpu->cache_flush_lock); > > spin_lock(&ptdev->gpu->reqs_lock); > + trace_gpu_cache_flush_start(ptdev->base.dev, l2, lsc, other); > if (!(ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED)) { > ptdev->gpu->pending_reqs |= GPU_IRQ_CLEAN_CACHES_COMPLETED; > gpu_write(gpu->iomem, GPU_CMD, GPU_FLUSH_CACHES(l2, lsc, > other)); > @@ -345,6 +346,7 @@ int panthor_gpu_flush_caches(struct panthor_device *ptdev, > > if (ret) { > spin_unlock(&ptdev->gpu->reqs_lock); > + trace_gpu_cache_flush_end(ptdev->base.dev, l2, lsc, other); > return ret; > } > > @@ -358,6 +360,7 @@ int panthor_gpu_flush_caches(struct panthor_device *ptdev, > ptdev->gpu->pending_reqs &= > ~GPU_IRQ_CLEAN_CACHES_COMPLETED; > } > spin_unlock(&ptdev->gpu->reqs_lock); > + trace_gpu_cache_flush_end(ptdev->base.dev, l2, lsc, other); > > if (ret) { > panthor_device_schedule_reset(ptdev); > diff --git a/drivers/gpu/drm/panthor/panthor_trace.h > b/drivers/gpu/drm/panthor/panthor_trace.h > index 6ffeb4fe6599..6951b95b1de7 100644 > --- a/drivers/gpu/drm/panthor/panthor_trace.h > +++ b/drivers/gpu/drm/panthor/panthor_trace.h > @@ -76,6 +76,55 @@ TRACE_EVENT(gpu_job_irq, > __entry->events, __entry->duration_ns) > ); > > +DECLARE_EVENT_CLASS(gpu_cache_flush_template, > + TP_PROTO(const struct device *dev, u32 l2, u32 lsc, u32 other), > + TP_ARGS(dev, l2, lsc, other), > + TP_STRUCT__entry( > + __string(dev_name, dev_name(dev)) > + __field(u32, l2) > + __field(u32, lsc) > + __field(u32, other) > + ), > + TP_fast_assign( > + __assign_str(dev_name); > + __entry->l2 = l2; > + __entry->lsc = lsc; > + __entry->other = other; > + ), > + TP_printk("%s: l2=0x%x lsc=0x%x other=0x%x", __get_str(dev_name), > + __entry->l2, __entry->lsc, __entry->other) > +); > + > +/** > + * gpu_cache_flush_start - called after cache flush locks taken, before flush > + * @dev: pointer to the &struct device, for printing the device name > + * @l2: "l2" flush flags > + * @lsc: "lsc" flush flags > + * @other: "other" flush flags > + * > + * Fires after any initial lock contention around the locks needed for > flushing > + * caches, but before the actual cache flush is requested. > + */ > +DEFINE_EVENT(gpu_cache_flush_template, gpu_cache_flush_start, > + TP_PROTO(const struct device *dev, u32 l2, u32 lsc, u32 other), > + TP_ARGS(dev, l2, lsc, other) > +); > + > +/** > + * gpu_cache_flush_end - called after cache flush > + * @dev: pointer to the &struct device, for printing the device name > + * @l2: "l2" flush flags > + * @lsc: "lsc" flush flags > + * @other: "other" flush flags > + * > + * Fires after either the cache flush is complete, or has failed. Can be used > + * together with gpu_cache_flush_start to get how long the flush has taken. > + */ > +DEFINE_EVENT(gpu_cache_flush_template, gpu_cache_flush_end, > + TP_PROTO(const struct device *dev, u32 l2, u32 lsc, u32 other), > + TP_ARGS(dev, l2, lsc, other) > +); > + > #endif /* __PANTHOR_TRACE_H__ */ > > #undef TRACE_INCLUDE_PATH >
