From c0f97f20e5d97a1358ade650fcf6a322c0c9bc72 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 24 Jul 2020 20:22:05 -0700 Subject: [PATCH] rcu: Move rcu_cpu_started per-CPU variable to rcu_data When the rcu_cpu_started per-CPU variable was added by commit f64c6013a202 ("rcu/x86: Provide early rcu_cpu_starting() callback"), there were multiple sets of per-CPU rcu_data structures. Therefore, the rcu_cpu_started flag was added as a separate per-CPU variable. But now there is only one set of per-CPU rcu_data structures, so this commit moves rcu_cpu_started to a new ->cpu_started field in that structure. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 13 +++++-------- kernel/rcu/tree.h | 1 + 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index da05afc53493..52108dd92169 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3967,8 +3967,6 @@ int rcutree_offline_cpu(unsigned int cpu) return 0; } -static DEFINE_PER_CPU(int, rcu_cpu_started); - /* * Mark the specified CPU as being online so that subsequent grace periods * (both expedited and normal) will wait on it. Note that this means that @@ -3988,12 +3986,11 @@ void rcu_cpu_starting(unsigned int cpu) struct rcu_node *rnp; bool newcpu; - if (per_cpu(rcu_cpu_started, cpu)) - return; - - per_cpu(rcu_cpu_started, cpu) = 1; - rdp = per_cpu_ptr(&rcu_data, cpu); + if (rdp->cpu_started) + return; + rdp->cpu_started = true; + rnp = rdp->mynode; mask = rdp->grpmask; raw_spin_lock_irqsave_rcu_node(rnp, flags); @@ -4053,7 +4050,7 @@ void rcu_report_dead(unsigned int cpu) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); raw_spin_unlock(&rcu_state.ofl_lock); - per_cpu(rcu_cpu_started, cpu) = 0; + rdp->cpu_started = false; } /* diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index c96ae351688b..309bc7f41d35 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -156,6 +156,7 @@ struct rcu_data { bool beenonline; /* CPU online at least once. */ bool gpwrap; /* Possible ->gp_seq wrap. */ bool exp_deferred_qs; /* This CPU awaiting a deferred QS? */ + bool cpu_started; /* RCU watching this onlining CPU. */ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ unsigned long grpmask; /* Mask to apply to leaf qsmask. */ unsigned long ticks_this_gp; /* The number of scheduling-clock */