From: Frederic Weisbecker Date: Wed, 15 May 2024 12:53:30 +0000 (+0200) Subject: rcu: Remove full memory barrier on boot time eqs sanity check X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e7a3c8ea6e2509f71150fa13b00da3ef2bbe2387;p=users%2Fjedix%2Flinux-maple.git rcu: Remove full memory barrier on boot time eqs sanity check When the boot CPU initializes the per-CPU data on behalf of all possible CPUs, a sanity check is performed on each of them to make sure none is initialized in an extended quiescent state. This check involves a full memory barrier which is useless at this early boot stage. Do a plain access instead. Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney Reviewed-by: Boqun Feng Reviewed-by: Neeraj Upadhyay --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index da5718da280d..57d813781749 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4786,7 +4786,7 @@ rcu_boot_init_percpu_data(int cpu) rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu); INIT_WORK(&rdp->strict_work, strict_work_handler); WARN_ON_ONCE(ct->dynticks_nesting != 1); - WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(cpu))); + WARN_ON_ONCE(rcu_dynticks_in_eqs(ct_dynticks_cpu(cpu))); rdp->barrier_seq_snap = rcu_state.barrier_sequence; rdp->rcu_ofl_gp_seq = rcu_state.gp_seq; rdp->rcu_ofl_gp_state = RCU_GP_CLEANED;