Commit a2203cfe authored by Marcelo Diop-Gonzalez's avatar Marcelo Diop-Gonzalez Committed by Greg Kroah-Hartman
Browse files

staging: vc04_services: don't increment service refcount when it's not needed 



There are a few places where a service's reference count is incremented,
something quick is done, and the refcount is dropped. This can be made
a little simpler/faster by not grabbing a reference in these cases.

Signed-off-by: default avatarMarcelo Diop-Gonzalez <marcgonzalez@google.com>
Link: https://lore.kernel.org/r/ac6186ac888f1acf489b5b504efcba8b0d6a8b25.1581532523.git.marcgonzalez@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3c27a36f

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

+8 −8
Original line number Diff line number Diff line
@@ -2497,11 +2497,11 @@ vchiq_instance_get_use_count(struct vchiq_instance *instance) 
	int use_count = 0, i;



	i = 0;

	while ((service = next_service_by_instance(instance->state,

		instance, &i))) {

	rcu_read_lock();

	while ((service = __next_service_by_instance(instance->state,

						     instance, &i)))

		use_count += service->service_use_count;

		unlock_service(service);

	}

	rcu_read_unlock();

	return use_count;

}
@@ -2524,11 +2524,11 @@ vchiq_instance_set_trace(struct vchiq_instance *instance, int trace) 
	int i;



	i = 0;

	while ((service = next_service_by_instance(instance->state,

		instance, &i))) {

	rcu_read_lock();

	while ((service = __next_service_by_instance(instance->state,

						     instance, &i)))

		service->trace = trace;

		unlock_service(service);

	}

	rcu_read_unlock();

	instance->trace = (trace != 0);

}

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c

+25 −11
Original line number Diff line number Diff line
@@ -222,28 +222,42 @@ find_closed_service_for_instance(struct vchiq_instance *instance, 
}



struct vchiq_service *

next_service_by_instance(struct vchiq_state *state, struct vchiq_instance *instance,

__next_service_by_instance(struct vchiq_state *state,

			   struct vchiq_instance *instance,

			   int *pidx)

{

	struct vchiq_service *service = NULL;

	int idx = *pidx;



	rcu_read_lock();

	while (idx < state->unused_service) {

		struct vchiq_service *srv;



		srv = rcu_dereference(state->services[idx++]);

		if (srv && srv->srvstate != VCHIQ_SRVSTATE_FREE &&

		    srv->instance == instance &&

		    kref_get_unless_zero(&srv->ref_count)) {

			service = rcu_pointer_handoff(srv);

		    srv->instance == instance) {

			service = srv;

			break;

		}

	}

	rcu_read_unlock();



	*pidx = idx;

	return service;

}



struct vchiq_service *

next_service_by_instance(struct vchiq_state *state,

			 struct vchiq_instance *instance,

			 int *pidx)

{

	struct vchiq_service *service;



	rcu_read_lock();

	service = __next_service_by_instance(state, instance, pidx);

	if (service && kref_get_unless_zero(&service->ref_count))

		service = rcu_pointer_handoff(service);

	else

		service = NULL;

	rcu_read_unlock();

	return service;

}
@@ -283,13 +297,13 @@ unlock_service(struct vchiq_service *service) 
int

vchiq_get_client_id(unsigned int handle)

{

	struct vchiq_service *service = find_service_by_handle(handle);

	struct vchiq_service *service;

	int id;



	rcu_read_lock();

	service = handle_to_service(handle);

	id = service ? service->client_id : 0;

	if (service)

		unlock_service(service);



	rcu_read_unlock();

	return id;

}

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h

+7 −1
Original line number Diff line number Diff line
@@ -572,7 +572,13 @@ find_closed_service_for_instance(struct vchiq_instance *instance, 
	unsigned int handle);



extern struct vchiq_service *

next_service_by_instance(struct vchiq_state *state, struct vchiq_instance *instance,

__next_service_by_instance(struct vchiq_state *state,

			   struct vchiq_instance *instance,

			   int *pidx);



extern struct vchiq_service *

next_service_by_instance(struct vchiq_state *state,

			 struct vchiq_instance *instance,

			 int *pidx);



extern void

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