diff options
| -rw-r--r-- | kernel/rcu/tree.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree_exp.h | 48 | ||||
| -rw-r--r-- | kernel/rcu/tree_trace.c | 7 |
3 files changed, 47 insertions, 9 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index f714f873bf9d..e99a5234d9ed 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -400,6 +400,7 @@ struct rcu_data { #ifdef CONFIG_RCU_FAST_NO_HZ struct rcu_head oom_head; #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ + atomic_long_t exp_workdone0; /* # done by workqueue. */ atomic_long_t exp_workdone1; /* # done by others #1. */ atomic_long_t exp_workdone2; /* # done by others #2. */ atomic_long_t exp_workdone3; /* # done by others #3. */ diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 1549f456fb7b..97f5ffe42b58 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -500,7 +500,6 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) * next GP, to proceed. */ mutex_lock(&rsp->exp_wake_mutex); - mutex_unlock(&rsp->exp_mutex); rcu_for_each_node_breadth_first(rsp, rnp) { if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) { @@ -516,6 +515,29 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) mutex_unlock(&rsp->exp_wake_mutex); } +/* Let the workqueue handler know what it is supposed to do. */ +struct rcu_exp_work { + smp_call_func_t rew_func; + struct rcu_state *rew_rsp; + unsigned long rew_s; + struct work_struct rew_work; +}; + +/* + * Work-queue handler to drive an expedited grace period forward. + */ +static void wait_rcu_exp_gp(struct work_struct *wp) +{ + struct rcu_exp_work *rewp; + + /* Initialize the rcu_node tree in preparation for the wait. */ + rewp = container_of(wp, struct rcu_exp_work, rew_work); + sync_rcu_exp_select_cpus(rewp->rew_rsp, rewp->rew_func); + + /* Wait and clean up, including waking everyone. */ + rcu_exp_wait_wake(rewp->rew_rsp, rewp->rew_s); +} + /* * Given an rcu_state pointer and a smp_call_function() handler, kick * off the specified flavor of expedited grace period. @@ -523,6 +545,9 @@ static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s) static void _synchronize_rcu_expedited(struct rcu_state *rsp, smp_call_func_t func) { + struct rcu_data *rdp; + struct rcu_exp_work rew; + struct rcu_node *rnp; unsigned long s; /* If expedited grace periods are prohibited, fall back to normal. */ @@ -536,11 +561,22 @@ static void _synchronize_rcu_expedited(struct rcu_state *rsp, if (exp_funnel_lock(rsp, s)) return; /* Someone else did our work for us. */ - /* Initialize the rcu_node tree in preparation for the wait. */ - sync_rcu_exp_select_cpus(rsp, func); - - /* Wait and clean up, including waking everyone. */ - rcu_exp_wait_wake(rsp, s); + /* Marshall arguments and schedule the expedited grace period. */ + rew.rew_func = func; + rew.rew_rsp = rsp; + rew.rew_s = s; + INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp); + schedule_work(&rew.rew_work); + + /* Wait for expedited grace period to complete. */ + rdp = per_cpu_ptr(rsp->rda, raw_smp_processor_id()); + rnp = rcu_get_root(rsp); + wait_event(rnp->exp_wq[(s >> 1) & 0x3], + sync_exp_work_done(rsp, + &rdp->exp_workdone0, s)); + + /* Let the next expedited grace period start. */ + mutex_unlock(&rsp->exp_mutex); } /** diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c index 86782f9a4604..b1f28972872c 100644 --- a/kernel/rcu/tree_trace.c +++ b/kernel/rcu/tree_trace.c @@ -185,16 +185,17 @@ static int show_rcuexp(struct seq_file *m, void *v) int cpu; struct rcu_state *rsp = (struct rcu_state *)m->private; struct rcu_data *rdp; - unsigned long s1 = 0, s2 = 0, s3 = 0; + unsigned long s0 = 0, s1 = 0, s2 = 0, s3 = 0; for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(rsp->rda, cpu); + s0 += atomic_long_read(&rdp->exp_workdone0); s1 += atomic_long_read(&rdp->exp_workdone1); s2 += atomic_long_read(&rdp->exp_workdone2); s3 += atomic_long_read(&rdp->exp_workdone3); } - seq_printf(m, "s=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", - rsp->expedited_sequence, s1, s2, s3, + seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", + rsp->expedited_sequence, s0, s1, s2, s3, atomic_long_read(&rsp->expedited_normal), atomic_read(&rsp->expedited_need_qs), rsp->expedited_sequence / 2); |