From 17ef2fe97c8c8e754e4a702c42f8e5b0ffadf4dd Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 27 Apr 2018 11:39:34 -0700 Subject: [PATCH] rcu: Make rcutorture's batches-completed API use ->gp_seq The rcutorture test invokes rcu_batches_started(), rcu_batches_completed(), rcu_batches_started_bh(), rcu_batches_completed_bh(), rcu_batches_started_sched(), and rcu_batches_completed_sched() to do grace-period consistency checks, and rcuperf uses the _completed variants for statistics. These functions use ->gpnum and ->completed. This commit therefore replaces them with rcu_get_gp_seq(), rcu_bh_get_gp_seq(), and rcu_sched_get_gp_seq(), adjusting rcutorture and rcuperf to make use of them. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcu.h | 18 +++++---------- kernel/rcu/rcuperf.c | 26 ++++++++------------- kernel/rcu/rcutorture.c | 50 +++++++++++++++------------------------- kernel/rcu/tree.c | 51 ++++++++++------------------------------- 4 files changed, 45 insertions(+), 100 deletions(-) diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index db0870acfdff..f0907f9f6cd0 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -463,12 +463,9 @@ void srcutorture_get_gp_data(enum rcutorture_type test_type, #endif #ifdef CONFIG_TINY_RCU -static inline unsigned long rcu_batches_started(void) { return 0; } -static inline unsigned long rcu_batches_started_bh(void) { return 0; } -static inline unsigned long rcu_batches_started_sched(void) { return 0; } -static inline unsigned long rcu_batches_completed(void) { return 0; } -static inline unsigned long rcu_batches_completed_bh(void) { return 0; } -static inline unsigned long rcu_batches_completed_sched(void) { return 0; } +static inline unsigned long rcu_get_gp_seq(void) { return 0; } +static inline unsigned long rcu_bh_get_gp_seq(void) { return 0; } +static inline unsigned long rcu_sched_get_gp_seq(void) { return 0; } static inline unsigned long rcu_exp_batches_completed(void) { return 0; } static inline unsigned long rcu_exp_batches_completed_sched(void) { return 0; } static inline unsigned long @@ -480,12 +477,9 @@ static inline void show_rcu_gp_kthreads(void) { } #else /* #ifdef CONFIG_TINY_RCU */ extern unsigned long rcutorture_testseq; extern unsigned long rcutorture_vernum; -unsigned long rcu_batches_started(void); -unsigned long rcu_batches_started_bh(void); -unsigned long rcu_batches_started_sched(void); -unsigned long rcu_batches_completed(void); -unsigned long rcu_batches_completed_bh(void); -unsigned long rcu_batches_completed_sched(void); +unsigned long rcu_get_gp_seq(void); +unsigned long rcu_bh_get_gp_seq(void); +unsigned long rcu_sched_get_gp_seq(void); unsigned long rcu_exp_batches_completed(void); unsigned long rcu_exp_batches_completed_sched(void); unsigned long srcu_batches_completed(struct srcu_struct *sp); diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index df29119b2013..2b5a613afcf3 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -138,8 +138,7 @@ struct rcu_perf_ops { void (*cleanup)(void); int (*readlock)(void); void (*readunlock)(int idx); - unsigned long (*started)(void); - unsigned long (*completed)(void); + unsigned long (*get_gp_seq)(void); unsigned long (*exp_completed)(void); void (*async)(struct rcu_head *head, rcu_callback_t func); void (*gp_barrier)(void); @@ -179,8 +178,7 @@ static struct rcu_perf_ops rcu_ops = { .init = rcu_sync_perf_init, .readlock = rcu_perf_read_lock, .readunlock = rcu_perf_read_unlock, - .started = rcu_batches_started, - .completed = rcu_batches_completed, + .get_gp_seq = rcu_get_gp_seq, .exp_completed = rcu_exp_batches_completed, .async = call_rcu, .gp_barrier = rcu_barrier, @@ -209,8 +207,7 @@ static struct rcu_perf_ops rcu_bh_ops = { .init = rcu_sync_perf_init, .readlock = rcu_bh_perf_read_lock, .readunlock = rcu_bh_perf_read_unlock, - .started = rcu_batches_started_bh, - .completed = rcu_batches_completed_bh, + .get_gp_seq = rcu_bh_get_gp_seq, .exp_completed = rcu_exp_batches_completed_sched, .async = call_rcu_bh, .gp_barrier = rcu_barrier_bh, @@ -266,8 +263,7 @@ static struct rcu_perf_ops srcu_ops = { .init = rcu_sync_perf_init, .readlock = srcu_perf_read_lock, .readunlock = srcu_perf_read_unlock, - .started = NULL, - .completed = srcu_perf_completed, + .get_gp_seq = srcu_perf_completed, .exp_completed = srcu_perf_completed, .async = srcu_call_rcu, .gp_barrier = srcu_rcu_barrier, @@ -295,8 +291,7 @@ static struct rcu_perf_ops srcud_ops = { .cleanup = srcu_sync_perf_cleanup, .readlock = srcu_perf_read_lock, .readunlock = srcu_perf_read_unlock, - .started = NULL, - .completed = srcu_perf_completed, + .get_gp_seq = srcu_perf_completed, .exp_completed = srcu_perf_completed, .async = srcu_call_rcu, .gp_barrier = srcu_rcu_barrier, @@ -325,8 +320,7 @@ static struct rcu_perf_ops sched_ops = { .init = rcu_sync_perf_init, .readlock = sched_perf_read_lock, .readunlock = sched_perf_read_unlock, - .started = rcu_batches_started_sched, - .completed = rcu_batches_completed_sched, + .get_gp_seq = rcu_sched_get_gp_seq, .exp_completed = rcu_exp_batches_completed_sched, .async = call_rcu_sched, .gp_barrier = rcu_barrier_sched, @@ -353,8 +347,7 @@ static struct rcu_perf_ops tasks_ops = { .init = rcu_sync_perf_init, .readlock = tasks_perf_read_lock, .readunlock = tasks_perf_read_unlock, - .started = rcu_no_completed, - .completed = rcu_no_completed, + .get_gp_seq = rcu_no_completed, .async = call_rcu_tasks, .gp_barrier = rcu_barrier_tasks, .sync = synchronize_rcu_tasks, @@ -447,8 +440,7 @@ rcu_perf_writer(void *arg) b_rcu_perf_writer_started = cur_ops->exp_completed() / 2; } else { - b_rcu_perf_writer_started = - cur_ops->completed(); + b_rcu_perf_writer_started = cur_ops->get_gp_seq(); } } @@ -505,7 +497,7 @@ retry: cur_ops->exp_completed() / 2; } else { b_rcu_perf_writer_finished = - cur_ops->completed(); + cur_ops->get_gp_seq(); } if (shutdown) { smp_mb(); /* Assign before wake. */ diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 5604bfac8df4..1f66597c7783 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -264,8 +264,7 @@ struct rcu_torture_ops { int (*readlock)(void); void (*read_delay)(struct torture_random_state *rrsp); void (*readunlock)(int idx); - unsigned long (*started)(void); - unsigned long (*completed)(void); + unsigned long (*get_gp_seq)(void); void (*deferred_free)(struct rcu_torture *p); void (*sync)(void); void (*exp_sync)(void); @@ -305,10 +304,10 @@ static void rcu_read_delay(struct torture_random_state *rrsp) * force_quiescent_state. */ if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { - started = cur_ops->completed(); + started = cur_ops->get_gp_seq(); ts = rcu_trace_clock_local(); mdelay(longdelay_ms); - completed = cur_ops->completed(); + completed = cur_ops->get_gp_seq(); do_trace_rcu_torture_read(cur_ops->name, NULL, ts, started, completed); } @@ -400,8 +399,7 @@ static struct rcu_torture_ops rcu_ops = { .readlock = rcu_torture_read_lock, .read_delay = rcu_read_delay, .readunlock = rcu_torture_read_unlock, - .started = rcu_batches_started, - .completed = rcu_batches_completed, + .get_gp_seq = rcu_get_gp_seq, .deferred_free = rcu_torture_deferred_free, .sync = synchronize_rcu, .exp_sync = synchronize_rcu_expedited, @@ -442,8 +440,7 @@ static struct rcu_torture_ops rcu_bh_ops = { .readlock = rcu_bh_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = rcu_bh_torture_read_unlock, - .started = rcu_batches_started_bh, - .completed = rcu_batches_completed_bh, + .get_gp_seq = rcu_bh_get_gp_seq, .deferred_free = rcu_bh_torture_deferred_free, .sync = synchronize_rcu_bh, .exp_sync = synchronize_rcu_bh_expedited, @@ -486,8 +483,7 @@ static struct rcu_torture_ops rcu_busted_ops = { .readlock = rcu_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = rcu_torture_read_unlock, - .started = rcu_no_completed, - .completed = rcu_no_completed, + .get_gp_seq = rcu_no_completed, .deferred_free = rcu_busted_torture_deferred_free, .sync = synchronize_rcu_busted, .exp_sync = synchronize_rcu_busted, @@ -575,8 +571,7 @@ static struct rcu_torture_ops srcu_ops = { .readlock = srcu_torture_read_lock, .read_delay = srcu_read_delay, .readunlock = srcu_torture_read_unlock, - .started = NULL, - .completed = srcu_torture_completed, + .get_gp_seq = srcu_torture_completed, .deferred_free = srcu_torture_deferred_free, .sync = srcu_torture_synchronize, .exp_sync = srcu_torture_synchronize_expedited, @@ -613,8 +608,7 @@ static struct rcu_torture_ops srcud_ops = { .readlock = srcu_torture_read_lock, .read_delay = srcu_read_delay, .readunlock = srcu_torture_read_unlock, - .started = NULL, - .completed = srcu_torture_completed, + .get_gp_seq = srcu_torture_completed, .deferred_free = srcu_torture_deferred_free, .sync = srcu_torture_synchronize, .exp_sync = srcu_torture_synchronize_expedited, @@ -651,8 +645,7 @@ static struct rcu_torture_ops sched_ops = { .readlock = sched_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = sched_torture_read_unlock, - .started = rcu_batches_started_sched, - .completed = rcu_batches_completed_sched, + .get_gp_seq = rcu_sched_get_gp_seq, .deferred_free = rcu_sched_torture_deferred_free, .sync = synchronize_sched, .exp_sync = synchronize_sched_expedited, @@ -690,8 +683,7 @@ static struct rcu_torture_ops tasks_ops = { .readlock = tasks_torture_read_lock, .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = tasks_torture_read_unlock, - .started = rcu_no_completed, - .completed = rcu_no_completed, + .get_gp_seq = rcu_no_completed, .deferred_free = rcu_tasks_torture_deferred_free, .sync = synchronize_rcu_tasks, .exp_sync = synchronize_rcu_tasks, @@ -1104,10 +1096,7 @@ static void rcu_torture_timer(struct timer_list *unused) unsigned long long ts; idx = cur_ops->readlock(); - if (cur_ops->started) - started = cur_ops->started(); - else - started = cur_ops->completed(); + started = cur_ops->get_gp_seq(); ts = rcu_trace_clock_local(); p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || @@ -1131,7 +1120,7 @@ static void rcu_torture_timer(struct timer_list *unused) /* Should not happen, but... */ pipe_count = RCU_TORTURE_PIPE_LEN; } - completed = cur_ops->completed(); + completed = cur_ops->get_gp_seq(); if (pipe_count > 1) { do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, started, completed); @@ -1139,8 +1128,8 @@ static void rcu_torture_timer(struct timer_list *unused) } __this_cpu_inc(rcu_torture_count[pipe_count]); completed = completed - started; - if (cur_ops->started) - completed++; + if (completed > ULONG_MAX >> 1) + completed = 0; /* Not all gp_seq have full range. */ if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; @@ -1187,10 +1176,7 @@ rcu_torture_reader(void *arg) mod_timer(&t, jiffies + 1); } idx = cur_ops->readlock(); - if (cur_ops->started) - started = cur_ops->started(); - else - started = cur_ops->completed(); + started = cur_ops->get_gp_seq(); ts = rcu_trace_clock_local(); p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || @@ -1212,7 +1198,7 @@ rcu_torture_reader(void *arg) /* Should not happen, but... */ pipe_count = RCU_TORTURE_PIPE_LEN; } - completed = cur_ops->completed(); + completed = cur_ops->get_gp_seq(); if (pipe_count > 1) { do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, started, completed); @@ -1220,8 +1206,8 @@ rcu_torture_reader(void *arg) } __this_cpu_inc(rcu_torture_count[pipe_count]); completed = completed - started; - if (cur_ops->started) - completed++; + if (completed > ULONG_MAX >> 1) + completed = 0; /* Not all gp_seq have full range. */ if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 3c3af7e2758f..547112bec26a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -530,58 +530,31 @@ static void force_quiescent_state(struct rcu_state *rsp); static int rcu_pending(void); /* - * Return the number of RCU batches started thus far for debug & stats. + * Return the number of RCU GPs completed thus far for debug & stats. */ -unsigned long rcu_batches_started(void) +unsigned long rcu_get_gp_seq(void) { - return rcu_state_p->gpnum; + return rcu_seq_ctr(READ_ONCE(rcu_state_p->gp_seq)); } -EXPORT_SYMBOL_GPL(rcu_batches_started); +EXPORT_SYMBOL_GPL(rcu_get_gp_seq); /* - * Return the number of RCU-sched batches started thus far for debug & stats. + * Return the number of RCU-sched GPs completed thus far for debug & stats. */ -unsigned long rcu_batches_started_sched(void) +unsigned long rcu_sched_get_gp_seq(void) { - return rcu_sched_state.gpnum; + return rcu_seq_ctr(READ_ONCE(rcu_sched_state.gp_seq)); } -EXPORT_SYMBOL_GPL(rcu_batches_started_sched); +EXPORT_SYMBOL_GPL(rcu_sched_get_gp_seq); /* - * Return the number of RCU BH batches started thus far for debug & stats. + * Return the number of RCU-bh GPs completed thus far for debug & stats. */ -unsigned long rcu_batches_started_bh(void) +unsigned long rcu_bh_get_gp_seq(void) { - return rcu_bh_state.gpnum; + return rcu_seq_ctr(READ_ONCE(rcu_bh_state.gp_seq)); } -EXPORT_SYMBOL_GPL(rcu_batches_started_bh); - -/* - * Return the number of RCU batches completed thus far for debug & stats. - */ -unsigned long rcu_batches_completed(void) -{ - return rcu_state_p->completed; -} -EXPORT_SYMBOL_GPL(rcu_batches_completed); - -/* - * Return the number of RCU-sched batches completed thus far for debug & stats. - */ -unsigned long rcu_batches_completed_sched(void) -{ - return rcu_sched_state.completed; -} -EXPORT_SYMBOL_GPL(rcu_batches_completed_sched); - -/* - * Return the number of RCU BH batches completed thus far for debug & stats. - */ -unsigned long rcu_batches_completed_bh(void) -{ - return rcu_bh_state.completed; -} -EXPORT_SYMBOL_GPL(rcu_batches_completed_bh); +EXPORT_SYMBOL_GPL(rcu_bh_get_gp_seq); /* * Return the number of RCU expedited batches completed thus far for