Commit 94df76a1 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Paul E. McKenney
Browse files

srcu: Remove superfluous sdp->srcu_lock_count zero filling 



Because alloc_percpu() zeroes out the allocated memory, there is no need
to zero-fill newly allocated per-CPU memory.  This commit therefore removes
the loop zeroing the ->srcu_lock_count and ->srcu_unlock_count arrays
from init_srcu_struct_nodes().  This is the only use of that function's
is_static parameter, which this commit also removes.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 6efb943b

kernel/rcu/srcutree.c

+2 −10
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ do { \ 
 * srcu_read_unlock() running against them.  So if the is_static parameter

 * is set, don't initialize ->srcu_lock_count[] and ->srcu_unlock_count[].

 */

static void init_srcu_struct_nodes(struct srcu_struct *ssp, bool is_static)

static void init_srcu_struct_nodes(struct srcu_struct *ssp)

{

	int cpu;

	int i;
@@ -148,14 +148,6 @@ static void init_srcu_struct_nodes(struct srcu_struct *ssp, bool is_static) 
		timer_setup(&sdp->delay_work, srcu_delay_timer, 0);

		sdp->ssp = ssp;

		sdp->grpmask = 1 << (cpu - sdp->mynode->grplo);

		if (is_static)

			continue;



		/* Dynamically allocated, better be no srcu_read_locks()! */

		for (i = 0; i < ARRAY_SIZE(sdp->srcu_lock_count); i++) {

			sdp->srcu_lock_count[i] = 0;

			sdp->srcu_unlock_count[i] = 0;

		}

	}

}
@@ -179,7 +171,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) 
		ssp->sda = alloc_percpu(struct srcu_data);

	if (!ssp->sda)

		return -ENOMEM;

	init_srcu_struct_nodes(ssp, is_static);

	init_srcu_struct_nodes(ssp);

	ssp->srcu_gp_seq_needed_exp = 0;

	ssp->srcu_last_gp_end = ktime_get_mono_fast_ns();

	smp_store_release(&ssp->srcu_gp_seq_needed, 0); /* Init done. */