diff options
| -rw-r--r-- | kernel/rcu/tree.c | 102 |
1 files changed, 35 insertions, 67 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d3428d4a68dc..2a49a04a1d98 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3352,7 +3352,7 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf) * Do boot-time initialization of a CPU's per-CPU RCU data. */ static void __init -rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) +rcu_boot_init_percpu_data(int cpu) { struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); @@ -3361,23 +3361,25 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->dynticks = &per_cpu(rcu_dynticks, cpu); WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1); WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp->dynticks))); - rdp->rcu_ofl_gp_seq = rsp->gp_seq; + rdp->rcu_ofl_gp_seq = rcu_state.gp_seq; rdp->rcu_ofl_gp_flags = RCU_GP_CLEANED; - rdp->rcu_onl_gp_seq = rsp->gp_seq; + rdp->rcu_onl_gp_seq = rcu_state.gp_seq; rdp->rcu_onl_gp_flags = RCU_GP_CLEANED; rdp->cpu = cpu; - rdp->rsp = rsp; + rdp->rsp = &rcu_state; rcu_boot_init_nocb_percpu_data(rdp); } /* - * Initialize a CPU's per-CPU RCU data. Note that only one online or + * Invoked early in the CPU-online process, when pretty much all services + * are available. The incoming CPU is not present. + * + * Initializes a CPU's per-CPU RCU data. Note that only one online or * offline event can be happening at a given time. Note also that we can * accept some slop in the rsp->gp_seq access due to the fact that this * CPU cannot possibly have any RCU callbacks in flight yet. */ -static void -rcu_init_percpu_data(int cpu, struct rcu_state *rsp) +int rcutree_prepare_cpu(unsigned int cpu) { unsigned long flags; struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); @@ -3386,7 +3388,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp) /* Set up local state, ensuring consistent view of global state. */ raw_spin_lock_irqsave_rcu_node(rnp, flags); rdp->qlen_last_fqs_check = 0; - rdp->n_force_qs_snap = rsp->n_force_qs; + rdp->n_force_qs_snap = rcu_state.n_force_qs; rdp->blimit = blimit; if (rcu_segcblist_empty(&rdp->cblist) && /* No early-boot CBs? */ !init_nocb_callback_list(rdp)) @@ -3410,21 +3412,8 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->core_needs_qs = false; rdp->rcu_iw_pending = false; rdp->rcu_iw_gp_seq = rnp->gp_seq - 1; - trace_rcu_grace_period(rsp->name, rdp->gp_seq, TPS("cpuonl")); + trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("cpuonl")); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); -} - -/* - * Invoked early in the CPU-online process, when pretty much all - * services are available. The incoming CPU is not present. - */ -int rcutree_prepare_cpu(unsigned int cpu) -{ - struct rcu_state *rsp; - - for_each_rcu_flavor(rsp) - rcu_init_percpu_data(cpu, rsp); - rcu_prepare_kthreads(cpu); rcu_spawn_all_nocb_kthreads(cpu); @@ -3548,23 +3537,32 @@ void rcu_cpu_starting(unsigned int cpu) #ifdef CONFIG_HOTPLUG_CPU /* - * The CPU is exiting the idle loop into the arch_cpu_idle_dead() - * function. We now remove it from the rcu_node tree's ->qsmaskinitnext - * bit masks. + * The outgoing function has no further need of RCU, so remove it from + * the rcu_node tree's ->qsmaskinitnext bit masks. + * + * Note that this function is special in that it is invoked directly + * from the outgoing CPU rather than from the cpuhp_step mechanism. + * This is because this function must be invoked at a precise location. */ -static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp) +void rcu_report_dead(unsigned int cpu) { unsigned long flags; unsigned long mask; struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */ + /* QS for any half-done expedited RCU-sched GP. */ + preempt_disable(); + rcu_report_exp_rdp(&rcu_state, this_cpu_ptr(&rcu_data)); + preempt_enable(); + rcu_preempt_deferred_qs(current); + /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ mask = rdp->grpmask; - spin_lock(&rsp->ofl_lock); + spin_lock(&rcu_state.ofl_lock); raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */ - rdp->rcu_ofl_gp_seq = READ_ONCE(rsp->gp_seq); - rdp->rcu_ofl_gp_flags = READ_ONCE(rsp->gp_flags); + rdp->rcu_ofl_gp_seq = READ_ONCE(rcu_state.gp_seq); + rdp->rcu_ofl_gp_flags = READ_ONCE(rcu_state.gp_flags); if (rnp->qsmask & mask) { /* RCU waiting on outgoing CPU? */ /* Report quiescent state -before- changing ->qsmaskinitnext! */ rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags); @@ -3572,34 +3570,17 @@ static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp) } rnp->qsmaskinitnext &= ~mask; raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - spin_unlock(&rsp->ofl_lock); -} - -/* - * The outgoing function has no further need of RCU, so remove it from - * the list of CPUs that RCU must track. - * - * Note that this function is special in that it is invoked directly - * from the outgoing CPU rather than from the cpuhp_step mechanism. - * This is because this function must be invoked at a precise location. - */ -void rcu_report_dead(unsigned int cpu) -{ - struct rcu_state *rsp; - - /* QS for any half-done expedited RCU-sched GP. */ - preempt_disable(); - rcu_report_exp_rdp(&rcu_state, this_cpu_ptr(&rcu_data)); - preempt_enable(); - rcu_preempt_deferred_qs(current); - for_each_rcu_flavor(rsp) - rcu_cleanup_dying_idle_cpu(cpu, rsp); + spin_unlock(&rcu_state.ofl_lock); per_cpu(rcu_cpu_started, cpu) = 0; } -/* Migrate the dead CPU's callbacks to the current CPU. */ -static void rcu_migrate_callbacks(int cpu, struct rcu_state *rsp) +/* + * The outgoing CPU has just passed through the dying-idle state, and we + * are being invoked from the CPU that was IPIed to continue the offline + * operation. Migrate the outgoing CPU's callbacks to the current CPU. + */ +void rcutree_migrate_callbacks(int cpu) { unsigned long flags; struct rcu_data *my_rdp; @@ -3632,19 +3613,6 @@ static void rcu_migrate_callbacks(int cpu, struct rcu_state *rsp) cpu, rcu_segcblist_n_cbs(&rdp->cblist), rcu_segcblist_first_cb(&rdp->cblist)); } - -/* - * The outgoing CPU has just passed through the dying-idle state, - * and we are being invoked from the CPU that was IPIed to continue the - * offline operation. We need to migrate the outgoing CPU's callbacks. - */ -void rcutree_migrate_callbacks(int cpu) -{ - struct rcu_state *rsp; - - for_each_rcu_flavor(rsp) - rcu_migrate_callbacks(cpu, rsp); -} #endif /* @@ -3814,7 +3782,7 @@ static void __init rcu_init_one(struct rcu_state *rsp) while (i > rnp->grphi) rnp++; per_cpu_ptr(&rcu_data, i)->mynode = rnp; - rcu_boot_init_percpu_data(i, rsp); + rcu_boot_init_percpu_data(i); } list_add(&rsp->flavors, &rcu_struct_flavors); } |