diff options
| -rw-r--r-- | kernel/rcu/rcu.h | 9 | ||||
| -rw-r--r-- | kernel/rcu/rcuperf.c | 18 | ||||
| -rw-r--r-- | kernel/rcu/rcutorture.c | 19 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 6 |
4 files changed, 41 insertions, 11 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 1c5cbd9d7c97..aa215d6355f8 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -143,6 +143,15 @@ static inline bool rcu_seq_new_gp(unsigned long old, unsigned long new) } /* + * Roughly how many full grace periods have elapsed between the collection + * of the two specified grace periods? + */ +static inline unsigned long rcu_seq_diff(unsigned long new, unsigned long old) +{ + return (new - old) >> RCU_SEQ_CTR_SHIFT; +} + +/* * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally * by call_rcu() and rcu callback execution, and are therefore not part of the * RCU API. Leaving in rcupdate.h because they are used by all RCU flavors. diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index 2b5a613afcf3..b080bc4a4f45 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -139,6 +139,7 @@ struct rcu_perf_ops { int (*readlock)(void); void (*readunlock)(int idx); unsigned long (*get_gp_seq)(void); + unsigned long (*gp_diff)(unsigned long new, unsigned long old); unsigned long (*exp_completed)(void); void (*async)(struct rcu_head *head, rcu_callback_t func); void (*gp_barrier)(void); @@ -179,6 +180,7 @@ static struct rcu_perf_ops rcu_ops = { .readlock = rcu_perf_read_lock, .readunlock = rcu_perf_read_unlock, .get_gp_seq = rcu_get_gp_seq, + .gp_diff = rcu_seq_diff, .exp_completed = rcu_exp_batches_completed, .async = call_rcu, .gp_barrier = rcu_barrier, @@ -208,6 +210,7 @@ static struct rcu_perf_ops rcu_bh_ops = { .readlock = rcu_bh_perf_read_lock, .readunlock = rcu_bh_perf_read_unlock, .get_gp_seq = rcu_bh_get_gp_seq, + .gp_diff = rcu_seq_diff, .exp_completed = rcu_exp_batches_completed_sched, .async = call_rcu_bh, .gp_barrier = rcu_barrier_bh, @@ -264,6 +267,7 @@ static struct rcu_perf_ops srcu_ops = { .readlock = srcu_perf_read_lock, .readunlock = srcu_perf_read_unlock, .get_gp_seq = srcu_perf_completed, + .gp_diff = rcu_seq_diff, .exp_completed = srcu_perf_completed, .async = srcu_call_rcu, .gp_barrier = srcu_rcu_barrier, @@ -292,6 +296,7 @@ static struct rcu_perf_ops srcud_ops = { .readlock = srcu_perf_read_lock, .readunlock = srcu_perf_read_unlock, .get_gp_seq = srcu_perf_completed, + .gp_diff = rcu_seq_diff, .exp_completed = srcu_perf_completed, .async = srcu_call_rcu, .gp_barrier = srcu_rcu_barrier, @@ -321,6 +326,7 @@ static struct rcu_perf_ops sched_ops = { .readlock = sched_perf_read_lock, .readunlock = sched_perf_read_unlock, .get_gp_seq = rcu_sched_get_gp_seq, + .gp_diff = rcu_seq_diff, .exp_completed = rcu_exp_batches_completed_sched, .async = call_rcu_sched, .gp_barrier = rcu_barrier_sched, @@ -348,6 +354,7 @@ static struct rcu_perf_ops tasks_ops = { .readlock = tasks_perf_read_lock, .readunlock = tasks_perf_read_unlock, .get_gp_seq = rcu_no_completed, + .gp_diff = rcu_seq_diff, .async = call_rcu_tasks, .gp_barrier = rcu_barrier_tasks, .sync = synchronize_rcu_tasks, @@ -355,6 +362,13 @@ static struct rcu_perf_ops tasks_ops = { .name = "tasks" }; +static unsigned long rcuperf_seq_diff(unsigned long new, unsigned long old) +{ + if (!cur_ops->gp_diff) + return new - old; + return cur_ops->gp_diff(new, old); +} + static bool __maybe_unused torturing_tasks(void) { return cur_ops == &tasks_ops; @@ -577,8 +591,8 @@ rcu_perf_cleanup(void) t_rcu_perf_writer_finished - t_rcu_perf_writer_started, ngps, - b_rcu_perf_writer_finished - - b_rcu_perf_writer_started); + rcuperf_seq_diff(b_rcu_perf_writer_finished, + b_rcu_perf_writer_started)); for (i = 0; i < nrealwriters; i++) { if (!writer_durations) break; diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 81fb43530d64..0481c7286875 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -265,6 +265,7 @@ struct rcu_torture_ops { void (*read_delay)(struct torture_random_state *rrsp); void (*readunlock)(int idx); unsigned long (*get_gp_seq)(void); + unsigned long (*gp_diff)(unsigned long new, unsigned long old); void (*deferred_free)(struct rcu_torture *p); void (*sync)(void); void (*exp_sync)(void); @@ -400,6 +401,7 @@ static struct rcu_torture_ops rcu_ops = { .read_delay = rcu_read_delay, .readunlock = rcu_torture_read_unlock, .get_gp_seq = rcu_get_gp_seq, + .gp_diff = rcu_seq_diff, .deferred_free = rcu_torture_deferred_free, .sync = synchronize_rcu, .exp_sync = synchronize_rcu_expedited, @@ -441,6 +443,7 @@ static struct rcu_torture_ops rcu_bh_ops = { .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = rcu_bh_torture_read_unlock, .get_gp_seq = rcu_bh_get_gp_seq, + .gp_diff = rcu_seq_diff, .deferred_free = rcu_bh_torture_deferred_free, .sync = synchronize_rcu_bh, .exp_sync = synchronize_rcu_bh_expedited, @@ -646,6 +649,7 @@ static struct rcu_torture_ops sched_ops = { .read_delay = rcu_read_delay, /* just reuse rcu's version. */ .readunlock = sched_torture_read_unlock, .get_gp_seq = rcu_sched_get_gp_seq, + .gp_diff = rcu_seq_diff, .deferred_free = rcu_sched_torture_deferred_free, .sync = synchronize_sched, .exp_sync = synchronize_sched_expedited, @@ -695,6 +699,13 @@ static struct rcu_torture_ops tasks_ops = { .name = "tasks" }; +static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) +{ + if (!cur_ops->gp_diff) + return new - old; + return cur_ops->gp_diff(new, old); +} + static bool __maybe_unused torturing_tasks(void) { return cur_ops == &tasks_ops; @@ -1127,9 +1138,7 @@ static void rcu_torture_timer(struct timer_list *unused) rcu_ftrace_dump(DUMP_ALL); } __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = completed - started; - if (completed > ULONG_MAX >> 1) - completed = 0; /* Not all gp_seq have full range. */ + completed = rcutorture_seq_diff(completed, started); if (completed > RCU_TORTURE_PIPE_LEN) { /* Should not happen, but... */ completed = RCU_TORTURE_PIPE_LEN; @@ -1205,9 +1214,7 @@ rcu_torture_reader(void *arg) rcu_ftrace_dump(DUMP_ALL); } __this_cpu_inc(rcu_torture_count[pipe_count]); - completed = completed - started; - if (completed > ULONG_MAX >> 1) - completed = 0; /* Not all gp_seq have full range. */ + completed = rcutorture_seq_diff(completed, started); 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 cbf2bcde5e60..fa219eea0ae7 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -532,7 +532,7 @@ static int rcu_pending(void); */ unsigned long rcu_get_gp_seq(void) { - return rcu_seq_ctr(READ_ONCE(rcu_state_p->gp_seq)); + return READ_ONCE(rcu_state_p->gp_seq); } EXPORT_SYMBOL_GPL(rcu_get_gp_seq); @@ -541,7 +541,7 @@ EXPORT_SYMBOL_GPL(rcu_get_gp_seq); */ unsigned long rcu_sched_get_gp_seq(void) { - return rcu_seq_ctr(READ_ONCE(rcu_sched_state.gp_seq)); + return READ_ONCE(rcu_sched_state.gp_seq); } EXPORT_SYMBOL_GPL(rcu_sched_get_gp_seq); @@ -550,7 +550,7 @@ EXPORT_SYMBOL_GPL(rcu_sched_get_gp_seq); */ unsigned long rcu_bh_get_gp_seq(void) { - return rcu_seq_ctr(READ_ONCE(rcu_bh_state.gp_seq)); + return READ_ONCE(rcu_bh_state.gp_seq); } EXPORT_SYMBOL_GPL(rcu_bh_get_gp_seq); |