Am 2022-04-11 um 08:52 schrieb philip yang:
On 2022-04-07 22:39, Felix Kuehling wrote:
The synchronize_rcu call in destroy_events can take several ms, which
noticeably slows down applications destroying many events. Use kfree_rcu
to free the event structure asynchronously and eliminate the
synchronize_rcu call in the user thread.
Will need similar fix in kfd_smi_ev_release, as I noticed sometime it
is slower to exit the app receiving SMI event.
Reviewed-by: Philip Yang <Philip.Yang@xxxxxxx>
Thanks. In the case of kfd_smi_ev_release you'd need to use call_rcu
because it's more than a simple kfree when you're freeing the
client->fifo. That would have some implications for module unloading,
too. Maybe you can simplify it by using DECLARE_KFIFO in struct
kfd_smi_client, since we create the fifo with a fixed size anway. That
way the cleanup is just a kfree_rcu(client).
Regards,
Felix
Signed-off-by: Felix Kuehling<Felix.Kuehling@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_events.c | 3 +--
drivers/gpu/drm/amd/amdkfd/kfd_events.h | 2 ++
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index 0fef24b0b915..75847c5d5957 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -262,8 +262,7 @@ static void destroy_event(struct kfd_process *p, struct kfd_event *ev)
p->signal_event_count--;
idr_remove(&p->event_idr, ev->event_id);
- synchronize_rcu();
- kfree(ev);
+ kfree_rcu(ev, rcu);
}
static void destroy_events(struct kfd_process *p)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.h b/drivers/gpu/drm/amd/amdkfd/kfd_events.h
index 55d376f56021..1c62c8dd6460 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.h
@@ -70,6 +70,8 @@ struct kfd_event {
struct kfd_hsa_memory_exception_data memory_exception_data;
struct kfd_hsa_hw_exception_data hw_exception_data;
};
+
+ struct rcu_head rcu; /* for asynchronous kfree_rcu */
};
#define KFD_EVENT_TIMEOUT_IMMEDIATE 0
