On Mon, Oct 15, 2012 at 02:56:07PM -0700, Paul E. McKenney wrote: > On Sat, Oct 13, 2012 at 01:14:16AM +0800, Lai Jiangshan wrote: > > In old days, we have two different API sets for dynamic-allocated per_cpu > > data > > and DEFINE_PER_CPU()-defined per_cpu data, and since we used > > dynamic-allocated per_cpu data, we can't use DEFINE_PER_CPU()-defined > > per_cpu data(otherwise we will introduce a lot of duplicated code. > > > > In new days, we have only one API sets for both type of per_cpu data, > > so we can use DEFINE_PER_CPU() for DEFINE_SRCU() which allows us > > define and init srcu struct in build time and allows us use srcu APIs > > in very early boot time. > > > > We also provide DEFINE_STATIC_SRCU() which defines an internal srcu struct > > inside a single *.c. > > > > Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com> > > --- > > include/linux/srcu.h | 30 ++++++++++++++++++++++++++++++ > > 1 files changed, 30 insertions(+), 0 deletions(-) > > > > diff --git a/include/linux/srcu.h b/include/linux/srcu.h > > index 5cce128..f986df1 100644 > > --- a/include/linux/srcu.h > > +++ b/include/linux/srcu.h > > @@ -42,6 +42,8 @@ struct rcu_batch { > > struct rcu_head *head, **tail; > > }; > > > > +#define RCU_BATCH_INIT(name) { NULL, &(name.head) } > > + > > struct srcu_struct { > > unsigned completed; > > struct srcu_struct_array __percpu *per_cpu_ref; > > @@ -72,14 +74,42 @@ int __init_srcu_struct(struct srcu_struct *sp, const > > char *name, > > __init_srcu_struct((sp), #sp, &__srcu_key); \ > > }) > > > > +#define __SRCU_DEP_MAP_INIT(srcu_name) .dep_map = { .name = #srcu_name > > }, > > #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > > > int init_srcu_struct(struct srcu_struct *sp); > > > > +#define __SRCU_DEP_MAP_INIT(srcu_name) > > #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > > > void process_srcu(struct work_struct *work); > > > > +#define __SRCU_STRUCT_INIT(name) \ > > + { \ > > + .completed = -300, \ > > + .per_cpu_ref = &name##_srcu_array, \ > > + .queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \ > > + .running = false, \ > > + .batch_queue = RCU_BATCH_INIT(name.batch_queue), \ > > + .batch_check0 = RCU_BATCH_INIT(name.batch_check0), \ > > + .batch_check1 = RCU_BATCH_INIT(name.batch_check1), \ > > + .batch_done = RCU_BATCH_INIT(name.batch_done), \ > > + .work = __DELAYED_WORK_INITIALIZER(name.work, process_srcu),\ > > + __SRCU_DEP_MAP_INIT(name) \ > > + } > > + > > +/* > > + * define and init a srcu struct at build time. > > + * dont't call init_srcu_struct() nor cleanup_srcu_struct() on it. > > + */ > > +#define DEFINE_SRCU(name) \ > > + static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\ > > + struct srcu_struct name = __SRCU_STRUCT_INIT(name); > > + > > +#define DEFINE_STATIC_SRCU(name) > > \ > > + static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\ > > + static struct srcu_struct name = __SRCU_STRUCT_INIT(name); > > + > > Why not collapse DEFINE_SRCU() and DEFINE_STATIC_SRCU() as follows? > > +#define DEFINE_SRCU(name) \ > + struct srcu_struct name = __SRCU_STRUCT_INIT(name); \ > + static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array); > > Then "static DEFINE_SRCU(foo)" would create a static srcu_struct without > the need for a separate DEFINE_STATIC_SRCU().
Never mind!!! This of course results in a forward reference and a compiler warning... Thanx, Paul > > /** > > * call_srcu() - Queue a callback for invocation after an SRCU grace period > > * @sp: srcu_struct in queue the callback > > -- > > 1.7.7.6 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/