From d6714c22b43fbcbead7e7b706ff270e15f04a791 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 22 Aug 2009 13:56:46 -0700 Subject: rcu: Renamings to increase RCU clarity Make RCU-sched, RCU-bh, and RCU-preempt be underlying implementations, with "RCU" defined in terms of one of the three. Update the outdated rcu_qsctr_inc() names, as these functions no longer increment anything. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746132696-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 80 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 50 insertions(+), 30 deletions(-) (limited to 'kernel/rcutree.c') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index a162f859dd32..4d71d4e8b5a8 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -74,26 +74,25 @@ EXPORT_SYMBOL_GPL(rcu_lock_map); .n_force_qs_ngp = 0, \ } -struct rcu_state rcu_state = RCU_STATE_INITIALIZER(rcu_state); -DEFINE_PER_CPU(struct rcu_data, rcu_data); +struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched_state); +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); /* - * Increment the quiescent state counter. - * The counter is a bit degenerated: We do not need to know + * Note a quiescent state. Because we do not need to know * how many quiescent states passed, just if there was at least - * one since the start of the grace period. Thus just a flag. + * one since the start of the grace period, this just sets a flag. */ -void rcu_qsctr_inc(int cpu) +void rcu_sched_qs(int cpu) { - struct rcu_data *rdp = &per_cpu(rcu_data, cpu); + struct rcu_data *rdp = &per_cpu(rcu_sched_data, cpu); rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; } -void rcu_bh_qsctr_inc(int cpu) +void rcu_bh_qs(int cpu) { struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu); rdp->passed_quiesc = 1; @@ -113,12 +112,22 @@ static int qlowmark = 100; /* Once only this many pending, use blimit. */ static void force_quiescent_state(struct rcu_state *rsp, int relaxed); +/* + * Return the number of RCU-sched batches processed thus far for debug & stats. + */ +long rcu_batches_completed_sched(void) +{ + return rcu_sched_state.completed; +} +EXPORT_SYMBOL_GPL(rcu_batches_completed_sched); + /* * Return the number of RCU batches processed thus far for debug & stats. + * @@@ placeholder, maps to rcu_batches_completed_sched(). */ long rcu_batches_completed(void) { - return rcu_state.completed; + return rcu_batches_completed_sched(); } EXPORT_SYMBOL_GPL(rcu_batches_completed); @@ -310,7 +319,7 @@ void rcu_irq_exit(void) WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs); /* If the interrupt queued a callback, get out of dyntick mode. */ - if (__get_cpu_var(rcu_data).nxtlist || + if (__get_cpu_var(rcu_sched_data).nxtlist || __get_cpu_var(rcu_bh_data).nxtlist) set_need_resched(); } @@ -847,7 +856,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) /* * Move callbacks from the outgoing CPU to the running CPU. * Note that the outgoing CPU is now quiscent, so it is now - * (uncharacteristically) safe to access it rcu_data structure. + * (uncharacteristically) safe to access its rcu_data structure. * Note also that we must carefully retain the order of the * outgoing CPU's callbacks in order for rcu_barrier() to work * correctly. Finally, note that we start all the callbacks @@ -878,7 +887,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) */ static void rcu_offline_cpu(int cpu) { - __rcu_offline_cpu(cpu, &rcu_state); + __rcu_offline_cpu(cpu, &rcu_sched_state); __rcu_offline_cpu(cpu, &rcu_bh_state); } @@ -973,17 +982,16 @@ void rcu_check_callbacks(int cpu, int user) * Get here if this CPU took its interrupt from user * mode or from the idle loop, and if this is not a * nested interrupt. In this case, the CPU is in - * a quiescent state, so count it. + * a quiescent state, so note it. * * No memory barrier is required here because both - * rcu_qsctr_inc() and rcu_bh_qsctr_inc() reference - * only CPU-local variables that other CPUs neither - * access nor modify, at least not while the corresponding - * CPU is online. + * rcu_sched_qs() and rcu_bh_qs() reference only CPU-local + * variables that other CPUs neither access nor modify, + * at least not while the corresponding CPU is online. */ - rcu_qsctr_inc(cpu); - rcu_bh_qsctr_inc(cpu); + rcu_sched_qs(cpu); + rcu_bh_qs(cpu); } else if (!in_softirq()) { @@ -991,10 +999,10 @@ void rcu_check_callbacks(int cpu, int user) * Get here if this CPU did not take its interrupt from * softirq, in other words, if it is not interrupting * a rcu_bh read-side critical section. This is an _bh - * critical section, so count it. + * critical section, so note it. */ - rcu_bh_qsctr_inc(cpu); + rcu_bh_qs(cpu); } raise_softirq(RCU_SOFTIRQ); } @@ -1174,7 +1182,8 @@ static void rcu_process_callbacks(struct softirq_action *unused) */ smp_mb(); /* See above block comment. */ - __rcu_process_callbacks(&rcu_state, &__get_cpu_var(rcu_data)); + __rcu_process_callbacks(&rcu_sched_state, + &__get_cpu_var(rcu_sched_data)); __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data)); /* @@ -1231,14 +1240,25 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), } /* - * Queue an RCU callback for invocation after a grace period. + * Queue an RCU-sched callback for invocation after a grace period. + */ +void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) +{ + __call_rcu(head, func, &rcu_sched_state); +} +EXPORT_SYMBOL_GPL(call_rcu_sched); + +/* + * @@@ Queue an RCU callback for invocation after a grace period. + * @@@ Placeholder pending rcutree_plugin.h. */ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) { - __call_rcu(head, func, &rcu_state); + call_rcu_sched(head, func); } EXPORT_SYMBOL_GPL(call_rcu); + /* * Queue an RCU for invocation after a quicker grace period. */ @@ -1311,7 +1331,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) */ int rcu_pending(int cpu) { - return __rcu_pending(&rcu_state, &per_cpu(rcu_data, cpu)) || + return __rcu_pending(&rcu_sched_state, &per_cpu(rcu_sched_data, cpu)) || __rcu_pending(&rcu_bh_state, &per_cpu(rcu_bh_data, cpu)); } @@ -1324,7 +1344,7 @@ int rcu_pending(int cpu) int rcu_needs_cpu(int cpu) { /* RCU callbacks either ready or pending? */ - return per_cpu(rcu_data, cpu).nxtlist || + return per_cpu(rcu_sched_data, cpu).nxtlist || per_cpu(rcu_bh_data, cpu).nxtlist; } @@ -1418,7 +1438,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp) static void __cpuinit rcu_online_cpu(int cpu) { - rcu_init_percpu_data(cpu, &rcu_state); + rcu_init_percpu_data(cpu, &rcu_sched_state); rcu_init_percpu_data(cpu, &rcu_bh_state); } @@ -1545,10 +1565,10 @@ void __init __rcu_init(void) #ifdef CONFIG_RCU_CPU_STALL_DETECTOR printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n"); #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ - rcu_init_one(&rcu_state); - RCU_DATA_PTR_INIT(&rcu_state, rcu_data); + rcu_init_one(&rcu_sched_state); + RCU_DATA_PTR_INIT(&rcu_sched_state, rcu_sched_data); for_each_possible_cpu(i) - rcu_boot_init_percpu_data(i, &rcu_state); + rcu_boot_init_percpu_data(i, &rcu_sched_state); rcu_init_one(&rcu_bh_state); RCU_DATA_PTR_INIT(&rcu_bh_state, rcu_bh_data); for_each_possible_cpu(i) -- cgit v1.2.3