srcutree: Suppress to-big transition for atomic SRCU

Initially (and perhaps forever), call_srcu() will not be available for
atomic srcu_struct structures.  There is therefore no reason to transition
such a structure to big, because the main purpose of such a transition
is to reduce lock contention for concurrent SRCU callback queueing.

This commit therefore adds an is_atomic parameter to both the
check_init_srcu_struct() and init_srcu_struct_fields() functions, which
suppresses the initialization-time transition to big that is enabled by
default on large systems.

It will still be possible to force a transition using rcutorture as a
destructive test.  This might (or might not) be adjusted later.

[ paulmck: Apply feedback from Kunwu Chan. ]

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

0 files changed, 0 insertions, 0 deletions