From de844846f72b152119faaef1b363448dc8ea368f Mon Sep 17 00:00:00 2001 From: Philip Yang Date: Wed, 4 Dec 2024 17:49:08 -0500 Subject: [PATCH] drm/amdkfd: Improve signal event slow path If event slot is not signaled, kfd_signal_event_interrupt goes to slow path to scan all event slots to find the signaled event, this is needed for old ASICs that don't have the event ID or the event IDs are incorrect in the IH payload. There is case that GPU signal the same event twice, then driver process the first event interrupt, set_event and event slot is auto-reset, then for the second event interrupt, KFD goes to slow path as event is not signaled, just drop the second event interrupt because the application only need wakeup once. Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_events.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c index ea37922492093..d075f24e5f9f3 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c @@ -748,6 +748,16 @@ void kfd_signal_event_interrupt(u32 pasid, uint32_t partial_id, uint64_t *slots = page_slots(p->signal_page); uint32_t id; + /* + * If id is valid but slot is not signaled, GPU may signal the same event twice + * before driver have chance to process the first interrupt, then signal slot is + * auto-reset after set_event wakeup the user space, just drop the second event as + * the application only need wakeup once. + */ + if ((valid_id_bits > 31 || (1U << valid_id_bits) >= KFD_SIGNAL_EVENT_LIMIT) && + partial_id < KFD_SIGNAL_EVENT_LIMIT && slots[partial_id] == UNSIGNALED_EVENT_SLOT) + goto out_unlock; + if (valid_id_bits) pr_debug_ratelimited("Partial ID invalid: %u (%u valid bits)\n", partial_id, valid_id_bits); @@ -776,6 +786,7 @@ void kfd_signal_event_interrupt(u32 pasid, uint32_t partial_id, } } +out_unlock: rcu_read_unlock(); kfd_unref_process(p); } -- 2.39.5