diff options
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 268 |
1 files changed, 134 insertions, 134 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 53ae9598f798..3ec8160fc75f 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -46,7 +46,6 @@ #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/time.h> -#include <linux/kernel_stat.h> #include "rcutree.h" @@ -66,11 +65,11 @@ static struct lock_class_key rcu_node_class[NUM_RCU_LVLS]; .signaled = RCU_GP_IDLE, \ .gpnum = -300, \ .completed = -300, \ - .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \ + .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&name.onofflock), \ .orphan_cbs_list = NULL, \ .orphan_cbs_tail = &name.orphan_cbs_list, \ .orphan_qlen = 0, \ - .fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \ + .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&name.fqslock), \ .n_force_qs = 0, \ .n_force_qs_ngp = 0, \ } @@ -81,9 +80,6 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state); DEFINE_PER_CPU(struct rcu_data, rcu_bh_data); -static int rcu_scheduler_active __read_mostly; - - /* * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s * permit this function to be invoked without holding the root rcu_node @@ -157,6 +153,24 @@ long rcu_batches_completed_bh(void) EXPORT_SYMBOL_GPL(rcu_batches_completed_bh); /* + * Force a quiescent state for RCU BH. + */ +void rcu_bh_force_quiescent_state(void) +{ + force_quiescent_state(&rcu_bh_state, 0); +} +EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state); + +/* + * Force a quiescent state for RCU-sched. + */ +void rcu_sched_force_quiescent_state(void) +{ + force_quiescent_state(&rcu_sched_state, 0); +} +EXPORT_SYMBOL_GPL(rcu_sched_force_quiescent_state); + +/* * Does the CPU have callbacks ready to be invoked? */ static int @@ -439,10 +453,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp) /* Only let one CPU complain about others per time interval. */ - spin_lock_irqsave(&rnp->lock, flags); + raw_spin_lock_irqsave(&rnp->lock, flags); delta = jiffies - rsp->jiffies_stall; if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) { - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK; @@ -452,13 +466,15 @@ static void print_other_cpu_stall(struct rcu_state *rsp) * due to CPU offlining. */ rcu_print_task_stall(rnp); - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); /* OK, time to rat on our buddy... */ printk(KERN_ERR "INFO: RCU detected CPU stalls:"); rcu_for_each_leaf_node(rsp, rnp) { + raw_spin_lock_irqsave(&rnp->lock, flags); rcu_print_task_stall(rnp); + raw_spin_unlock_irqrestore(&rnp->lock, flags); if (rnp->qsmask == 0) continue; for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++) @@ -469,6 +485,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp) smp_processor_id(), (long)(jiffies - rsp->gp_start)); trigger_all_cpu_backtrace(); + /* If so configured, complain about tasks blocking the grace period. */ + + rcu_print_detail_task_stall(rsp); + force_quiescent_state(rsp, 0); /* Kick them all. */ } @@ -481,11 +501,11 @@ static void print_cpu_stall(struct rcu_state *rsp) smp_processor_id(), jiffies - rsp->gp_start); trigger_all_cpu_backtrace(); - spin_lock_irqsave(&rnp->lock, flags); - if ((long)(jiffies - rsp->jiffies_stall) >= 0) + raw_spin_lock_irqsave(&rnp->lock, flags); + if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall)) rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK; - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); set_need_resched(); /* kick ourselves to get things going. */ } @@ -545,12 +565,12 @@ static void note_new_gpnum(struct rcu_state *rsp, struct rcu_data *rdp) local_irq_save(flags); rnp = rdp->mynode; if (rdp->gpnum == ACCESS_ONCE(rnp->gpnum) || /* outside lock. */ - !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */ + !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */ local_irq_restore(flags); return; } __note_new_gpnum(rsp, rnp, rdp); - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -609,12 +629,12 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp) local_irq_save(flags); rnp = rdp->mynode; if (rdp->completed == ACCESS_ONCE(rnp->completed) || /* outside lock. */ - !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */ + !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */ local_irq_restore(flags); return; } __rcu_process_gp_end(rsp, rnp, rdp); - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -659,12 +679,14 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) struct rcu_data *rdp = rsp->rda[smp_processor_id()]; struct rcu_node *rnp = rcu_get_root(rsp); - if (!cpu_needs_another_gp(rsp, rdp)) { + if (!cpu_needs_another_gp(rsp, rdp) || rsp->fqs_active) { + if (cpu_needs_another_gp(rsp, rdp)) + rsp->fqs_need_gp = 1; if (rnp->completed == rsp->completed) { - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ /* * Propagate new ->completed value to rcu_node structures @@ -672,9 +694,9 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) * of the next grace period to process their callbacks. */ rcu_for_each_node_breadth_first(rsp, rnp) { - spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ rnp->completed = rsp->completed; - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } local_irq_restore(flags); return; @@ -695,15 +717,15 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) rnp->completed = rsp->completed; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ rcu_start_gp_per_cpu(rsp, rnp, rdp); - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - spin_unlock(&rnp->lock); /* leave irqs disabled. */ + raw_spin_unlock(&rnp->lock); /* leave irqs disabled. */ /* Exclude any concurrent CPU-hotplug operations. */ - spin_lock(&rsp->onofflock); /* irqs already disabled. */ + raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */ /* * Set the quiescent-state-needed bits in all the rcu_node @@ -723,21 +745,21 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) * irqs disabled. */ rcu_for_each_node_breadth_first(rsp, rnp) { - spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ rcu_preempt_check_blocked_tasks(rnp); rnp->qsmask = rnp->qsmaskinit; rnp->gpnum = rsp->gpnum; rnp->completed = rsp->completed; if (rnp == rdp->mynode) rcu_start_gp_per_cpu(rsp, rnp, rdp); - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } rnp = rcu_get_root(rsp); - spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */ - spin_unlock(&rnp->lock); /* irqs remain disabled. */ - spin_unlock_irqrestore(&rsp->onofflock, flags); + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock_irqrestore(&rsp->onofflock, flags); } /* @@ -776,14 +798,14 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, if (!(rnp->qsmask & mask)) { /* Our bit has already been cleared, so done. */ - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } rnp->qsmask &= ~mask; if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) { /* Other bits still set at this level, so done. */ - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } mask = rnp->grpmask; @@ -793,10 +815,10 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, break; } - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); rnp_c = rnp; rnp = rnp->parent; - spin_lock_irqsave(&rnp->lock, flags); + raw_spin_lock_irqsave(&rnp->lock, flags); WARN_ON_ONCE(rnp_c->qsmask); } @@ -825,7 +847,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las struct rcu_node *rnp; rnp = rdp->mynode; - spin_lock_irqsave(&rnp->lock, flags); + raw_spin_lock_irqsave(&rnp->lock, flags); if (lastcomp != rnp->completed) { /* @@ -837,12 +859,12 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las * race occurred. */ rdp->passed_quiesc = 0; /* try again later! */ - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } mask = rdp->grpmask; if ((rnp->qsmask & mask) == 0) { - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } else { rdp->qs_pending = 0; @@ -906,7 +928,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp) if (rdp->nxtlist == NULL) return; /* irqs disabled, so comparison is stable. */ - spin_lock(&rsp->onofflock); /* irqs already disabled. */ + raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */ *rsp->orphan_cbs_tail = rdp->nxtlist; rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL]; rdp->nxtlist = NULL; @@ -914,7 +936,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp) rdp->nxttail[i] = &rdp->nxtlist; rsp->orphan_qlen += rdp->qlen; rdp->qlen = 0; - spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ + raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ } /* @@ -925,10 +947,10 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) unsigned long flags; struct rcu_data *rdp; - spin_lock_irqsave(&rsp->onofflock, flags); + raw_spin_lock_irqsave(&rsp->onofflock, flags); rdp = rsp->rda[smp_processor_id()]; if (rsp->orphan_cbs_list == NULL) { - spin_unlock_irqrestore(&rsp->onofflock, flags); + raw_spin_unlock_irqrestore(&rsp->onofflock, flags); return; } *rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list; @@ -937,7 +959,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) rsp->orphan_cbs_list = NULL; rsp->orphan_cbs_tail = &rsp->orphan_cbs_list; rsp->orphan_qlen = 0; - spin_unlock_irqrestore(&rsp->onofflock, flags); + raw_spin_unlock_irqrestore(&rsp->onofflock, flags); } /* @@ -953,23 +975,23 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) struct rcu_node *rnp; /* Exclude any attempts to start a new grace period. */ - spin_lock_irqsave(&rsp->onofflock, flags); + raw_spin_lock_irqsave(&rsp->onofflock, flags); /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */ rnp = rdp->mynode; /* this is the outgoing CPU's rnp. */ mask = rdp->grpmask; /* rnp->grplo is constant. */ do { - spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ rnp->qsmaskinit &= ~mask; if (rnp->qsmaskinit != 0) { if (rnp != rdp->mynode) - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ break; } if (rnp == rdp->mynode) need_report = rcu_preempt_offline_tasks(rsp, rnp, rdp); else - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ mask = rnp->grpmask; rnp = rnp->parent; } while (rnp != NULL); @@ -980,12 +1002,12 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) * because invoking rcu_report_unblock_qs_rnp() with ->onofflock * held leads to deadlock. */ - spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ + raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ rnp = rdp->mynode; if (need_report & RCU_OFL_TASKS_NORM_GP) rcu_report_unblock_qs_rnp(rnp, flags); else - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); if (need_report & RCU_OFL_TASKS_EXP_GP) rcu_report_exp_rnp(rsp, rnp); @@ -1144,11 +1166,9 @@ void rcu_check_callbacks(int cpu, int user) /* * Scan the leaf rcu_node structures, processing dyntick state for any that * have not yet encountered a quiescent state, using the function specified. - * Returns 1 if the current grace period ends while scanning (possibly - * because we made it end). + * The caller must have suppressed start of new grace periods. */ -static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, - int (*f)(struct rcu_data *)) +static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) { unsigned long bit; int cpu; @@ -1158,13 +1178,13 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, rcu_for_each_leaf_node(rsp, rnp) { mask = 0; - spin_lock_irqsave(&rnp->lock, flags); - if (rnp->completed != lastcomp) { - spin_unlock_irqrestore(&rnp->lock, flags); - return 1; + raw_spin_lock_irqsave(&rnp->lock, flags); + if (!rcu_gp_in_progress(rsp)) { + raw_spin_unlock_irqrestore(&rnp->lock, flags); + return; } if (rnp->qsmask == 0) { - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); continue; } cpu = rnp->grplo; @@ -1173,15 +1193,14 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu])) mask |= bit; } - if (mask != 0 && rnp->completed == lastcomp) { + if (mask != 0) { /* rcu_report_qs_rnp() releases rnp->lock. */ rcu_report_qs_rnp(mask, rsp, rnp, flags); continue; } - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } - return 0; } /* @@ -1191,32 +1210,26 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, static void force_quiescent_state(struct rcu_state *rsp, int relaxed) { unsigned long flags; - long lastcomp; struct rcu_node *rnp = rcu_get_root(rsp); - u8 signaled; - u8 forcenow; if (!rcu_gp_in_progress(rsp)) return; /* No grace period in progress, nothing to force. */ - if (!spin_trylock_irqsave(&rsp->fqslock, flags)) { + if (!raw_spin_trylock_irqsave(&rsp->fqslock, flags)) { rsp->n_force_qs_lh++; /* Inexact, can lose counts. Tough! */ return; /* Someone else is already on the job. */ } - if (relaxed && - (long)(rsp->jiffies_force_qs - jiffies) >= 0) - goto unlock_ret; /* no emergency and done recently. */ + if (relaxed && ULONG_CMP_GE(rsp->jiffies_force_qs, jiffies)) + goto unlock_fqs_ret; /* no emergency and done recently. */ rsp->n_force_qs++; - spin_lock(&rnp->lock); - lastcomp = rsp->gpnum - 1; - signaled = rsp->signaled; + raw_spin_lock(&rnp->lock); /* irqs already disabled */ rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; if(!rcu_gp_in_progress(rsp)) { rsp->n_force_qs_ngp++; - spin_unlock(&rnp->lock); - goto unlock_ret; /* no GP in progress, time updated. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled */ + goto unlock_fqs_ret; /* no GP in progress, time updated. */ } - spin_unlock(&rnp->lock); - switch (signaled) { + rsp->fqs_active = 1; + switch (rsp->signaled) { case RCU_GP_IDLE: case RCU_GP_INIT: @@ -1224,45 +1237,38 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) case RCU_SAVE_DYNTICK: + raw_spin_unlock(&rnp->lock); /* irqs remain disabled */ if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK) break; /* So gcc recognizes the dead code. */ /* Record dyntick-idle state. */ - if (rcu_process_dyntick(rsp, lastcomp, - dyntick_save_progress_counter)) - goto unlock_ret; - /* fall into next case. */ - - case RCU_SAVE_COMPLETED: - - /* Update state, record completion counter. */ - forcenow = 0; - spin_lock(&rnp->lock); - if (lastcomp + 1 == rsp->gpnum && - lastcomp == rsp->completed && - rsp->signaled == signaled) { + force_qs_rnp(rsp, dyntick_save_progress_counter); + raw_spin_lock(&rnp->lock); /* irqs already disabled */ + if (rcu_gp_in_progress(rsp)) rsp->signaled = RCU_FORCE_QS; - rsp->completed_fqs = lastcomp; - forcenow = signaled == RCU_SAVE_COMPLETED; - } - spin_unlock(&rnp->lock); - if (!forcenow) - break; - /* fall into next case. */ + break; case RCU_FORCE_QS: /* Check dyntick-idle state, send IPI to laggarts. */ - if (rcu_process_dyntick(rsp, rsp->completed_fqs, - rcu_implicit_dynticks_qs)) - goto unlock_ret; + raw_spin_unlock(&rnp->lock); /* irqs remain disabled */ + force_qs_rnp(rsp, rcu_implicit_dynticks_qs); /* Leave state in case more forcing is required. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled */ break; } -unlock_ret: - spin_unlock_irqrestore(&rsp->fqslock, flags); + rsp->fqs_active = 0; + if (rsp->fqs_need_gp) { + raw_spin_unlock(&rsp->fqslock); /* irqs remain disabled */ + rsp->fqs_need_gp = 0; + rcu_start_gp(rsp, flags); /* releases rnp->lock */ + return; + } + raw_spin_unlock(&rnp->lock); /* irqs remain disabled */ +unlock_fqs_ret: + raw_spin_unlock_irqrestore(&rsp->fqslock, flags); } #else /* #ifdef CONFIG_SMP */ @@ -1290,7 +1296,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) * If an RCU GP has gone long enough, go check for dyntick * idle CPUs and, if needed, send resched IPIs. */ - if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0) + if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies)) force_quiescent_state(rsp, 1); /* @@ -1304,7 +1310,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) /* Does this CPU require a not-yet-started grace period? */ if (cpu_needs_another_gp(rsp, rdp)) { - spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags); + raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags); rcu_start_gp(rsp, flags); /* releases above lock */ } @@ -1335,6 +1341,9 @@ static void rcu_process_callbacks(struct softirq_action *unused) * grace-period manipulations above. */ smp_mb(); /* See above block comment. */ + + /* If we are last CPU on way to dyntick-idle mode, accelerate it. */ + rcu_needs_cpu_flush(); } static void @@ -1369,7 +1378,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), unsigned long nestflag; struct rcu_node *rnp_root = rcu_get_root(rsp); - spin_lock_irqsave(&rnp_root->lock, nestflag); + raw_spin_lock_irqsave(&rnp_root->lock, nestflag); rcu_start_gp(rsp, nestflag); /* releases rnp_root->lock. */ } @@ -1387,7 +1396,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), force_quiescent_state(rsp, 0); rdp->n_force_qs_snap = rsp->n_force_qs; rdp->qlen_last_fqs_check = rdp->qlen; - } else if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0) + } else if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies)) force_quiescent_state(rsp, 1); local_irq_restore(flags); } @@ -1520,7 +1529,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) /* Has an RCU GP gone long enough to send resched IPIs &c? */ if (rcu_gp_in_progress(rsp) && - ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) { + ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies)) { rdp->n_rp_need_fqs++; return 1; } @@ -1545,10 +1554,9 @@ static int rcu_pending(int cpu) /* * Check to see if any future RCU-related work will need to be done * by the current CPU, even if none need be done immediately, returning - * 1 if so. This function is part of the RCU implementation; it is -not- - * an exported member of the RCU API. + * 1 if so. */ -int rcu_needs_cpu(int cpu) +static int rcu_needs_cpu_quick_check(int cpu) { /* RCU callbacks either ready or pending? */ return per_cpu(rcu_sched_data, cpu).nxtlist || @@ -1556,21 +1564,6 @@ int rcu_needs_cpu(int cpu) rcu_preempt_needs_cpu(cpu); } -/* - * This function is invoked towards the end of the scheduler's initialization - * process. Before this is called, the idle task might contain - * RCU read-side critical sections (during which time, this idle - * task is booting the system). After this function is called, the - * idle tasks are prohibited from containing RCU read-side critical - * sections. - */ -void rcu_scheduler_starting(void) -{ - WARN_ON(num_online_cpus() != 1); - WARN_ON(nr_context_switches() > 0); - rcu_scheduler_active = 1; -} - static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL}; static atomic_t rcu_barrier_cpu_count; static DEFINE_MUTEX(rcu_barrier_mutex); @@ -1659,7 +1652,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) struct rcu_node *rnp = rcu_get_root(rsp); /* Set up local state, ensuring consistent view of global state. */ - spin_lock_irqsave(&rnp->lock, flags); + raw_spin_lock_irqsave(&rnp->lock, flags); rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo); rdp->nxtlist = NULL; for (i = 0; i < RCU_NEXT_SIZE; i++) @@ -1669,7 +1662,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->dynticks = &per_cpu(rcu_dynticks, cpu); #endif /* #ifdef CONFIG_NO_HZ */ rdp->cpu = cpu; - spin_unlock_irqrestore(&rnp->lock, flags); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -1687,7 +1680,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) struct rcu_node *rnp = rcu_get_root(rsp); /* Set up local state, ensuring consistent view of global state. */ - spin_lock_irqsave(&rnp->lock, flags); + raw_spin_lock_irqsave(&rnp->lock, flags); rdp->passed_quiesc = 0; /* We could be racing with new GP, */ rdp->qs_pending = 1; /* so set up to respond to current GP. */ rdp->beenonline = 1; /* We have now been online. */ @@ -1695,7 +1688,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) rdp->qlen_last_fqs_check = 0; rdp->n_force_qs_snap = rsp->n_force_qs; rdp->blimit = blimit; - spin_unlock(&rnp->lock); /* irqs remain disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ /* * A new grace period might start here. If so, we won't be part @@ -1703,14 +1696,14 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) */ /* Exclude any attempts to start a new GP on large systems. */ - spin_lock(&rsp->onofflock); /* irqs already disabled. */ + raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */ /* Add CPU to rcu_node bitmasks. */ rnp = rdp->mynode; mask = rdp->grpmask; do { /* Exclude any attempts to start a new GP on small systems. */ - spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock(&rnp->lock); /* irqs already disabled. */ rnp->qsmaskinit |= mask; mask = rnp->grpmask; if (rnp == rdp->mynode) { @@ -1718,11 +1711,11 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) rdp->completed = rnp->completed; rdp->passed_quiesc_completed = rnp->completed - 1; } - spin_unlock(&rnp->lock); /* irqs already disabled. */ + raw_spin_unlock(&rnp->lock); /* irqs already disabled. */ rnp = rnp->parent; } while (rnp != NULL && !(rnp->qsmaskinit & mask)); - spin_unlock_irqrestore(&rsp->onofflock, flags); + raw_spin_unlock_irqrestore(&rsp->onofflock, flags); } static void __cpuinit rcu_online_cpu(int cpu) @@ -1806,11 +1799,17 @@ static void __init rcu_init_levelspread(struct rcu_state *rsp) */ static void __init rcu_init_one(struct rcu_state *rsp) { + static char *buf[] = { "rcu_node_level_0", + "rcu_node_level_1", + "rcu_node_level_2", + "rcu_node_level_3" }; /* Match MAX_RCU_LVLS */ int cpustride = 1; int i; int j; struct rcu_node *rnp; + BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */ + /* Initialize the level-tracking arrays. */ for (i = 1; i < NUM_RCU_LVLS; i++) @@ -1823,8 +1822,9 @@ static void __init rcu_init_one(struct rcu_state *rsp) cpustride *= rsp->levelspread[i]; rnp = rsp->level[i]; for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) { - spin_lock_init(&rnp->lock); - lockdep_set_class(&rnp->lock, &rcu_node_class[i]); + raw_spin_lock_init(&rnp->lock); + lockdep_set_class_and_name(&rnp->lock, + &rcu_node_class[i], buf[i]); rnp->gpnum = 0; rnp->qsmask = 0; rnp->qsmaskinit = 0; @@ -1876,7 +1876,7 @@ do { \ void __init rcu_init(void) { - int i; + int cpu; rcu_bootup_announce(); #ifdef CONFIG_RCU_CPU_STALL_DETECTOR @@ -1896,8 +1896,8 @@ void __init rcu_init(void) * or the scheduler are operational. */ cpu_notifier(rcu_cpu_notify, 0); - for_each_online_cpu(i) - rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)i); + for_each_online_cpu(cpu) + rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu); } #include "rcutree_plugin.h" |