On Thu, Aug 22, 2024 at 11:21:28AM +0800, Zhen Lei wrote: > The value of ARRAY_SIZE() can be determined at compile time, so if both > sides of the equation are ARRAY_SIZE(), using BUILD_BUG_ON() can help us > catch the problem earlier. > > While there are cases where unequal array sizes will work, there is no > point in allowing them, so it makes more sense to force them to be equal > using BUILD_BUG_ON(). > > Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Paul E. McKenney <[email protected]> > --- > kernel/rcu/srcutree.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c > index b24db425f16d850..a9c7795bb77d650 100644 > --- a/kernel/rcu/srcutree.c > +++ b/kernel/rcu/srcutree.c > @@ -128,7 +128,7 @@ static void init_srcu_struct_data(struct srcu_struct *ssp) > * Initialize the per-CPU srcu_data array, which feeds into the > * leaves of the srcu_node tree. > */ > - WARN_ON_ONCE(ARRAY_SIZE(sdp->srcu_lock_count) != > + BUILD_BUG_ON(ARRAY_SIZE(sdp->srcu_lock_count) != > ARRAY_SIZE(sdp->srcu_unlock_count)); > for_each_possible_cpu(cpu) { > sdp = per_cpu_ptr(ssp->sda, cpu); > @@ -186,7 +186,7 @@ static bool init_srcu_struct_nodes(struct srcu_struct > *ssp, gfp_t gfp_flags) > /* Each pass through this loop initializes one srcu_node structure. */ > srcu_for_each_node_breadth_first(ssp, snp) { > spin_lock_init(&ACCESS_PRIVATE(snp, lock)); > - WARN_ON_ONCE(ARRAY_SIZE(snp->srcu_have_cbs) != > + BUILD_BUG_ON(ARRAY_SIZE(snp->srcu_have_cbs) != > ARRAY_SIZE(snp->srcu_data_have_cbs)); > for (i = 0; i < ARRAY_SIZE(snp->srcu_have_cbs); i++) { > snp->srcu_have_cbs[i] = SRCU_SNP_INIT_SEQ; > -- > 2.34.1 >
