diff options
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 11 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 17 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree_exp.h | 12 |
4 files changed, 28 insertions, 13 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index bf08fee53dc7..87c51225ceec 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -289,15 +289,24 @@ static int rcu_torture_read_lock(void) __acquires(RCU) static void rcu_read_delay(struct torture_random_state *rrsp) { + unsigned long started; + unsigned long completed; const unsigned long shortdelay_us = 200; const unsigned long longdelay_ms = 50; + unsigned long long ts; /* We want a short delay sometimes to make a reader delay the grace * period, and we want a long delay occasionally to trigger * force_quiescent_state. */ - if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) + if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { + started = cur_ops->completed(); + ts = rcu_trace_clock_local(); mdelay(longdelay_ms); + completed = cur_ops->completed(); + do_trace_rcu_torture_read(cur_ops->name, NULL, ts, + started, completed); + } if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) udelay(shortdelay_us); #ifdef CONFIG_PREEMPT diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 69a5611a7e7c..96c52e43f7ca 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1304,7 +1304,8 @@ static void rcu_stall_kick_kthreads(struct rcu_state *rsp) if (!rcu_kick_kthreads) return; j = READ_ONCE(rsp->jiffies_kick_kthreads); - if (time_after(jiffies, j) && rsp->gp_kthread) { + if (time_after(jiffies, j) && rsp->gp_kthread && + (rcu_gp_in_progress(rsp) || READ_ONCE(rsp->gp_flags))) { WARN_ONCE(1, "Kicking %s grace-period kthread\n", rsp->name); rcu_ftrace_dump(DUMP_ALL); wake_up_process(rsp->gp_kthread); @@ -2828,8 +2829,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) * Also schedule RCU core processing. * * This function must be called from hardirq context. It is normally - * invoked from the scheduling-clock interrupt. If rcu_pending returns - * false, there is no point in invoking rcu_check_callbacks(). + * invoked from the scheduling-clock interrupt. */ void rcu_check_callbacks(int user) { @@ -3121,7 +3121,9 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, unsigned long flags; struct rcu_data *rdp; - WARN_ON_ONCE((unsigned long)head & 0x1); /* Misaligned rcu_head! */ + /* Misaligned rcu_head! */ + WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1)); + if (debug_rcu_head_queue(head)) { /* Probable double call_rcu(), so leak the callback. */ WRITE_ONCE(head->func, rcu_leak_callback); @@ -3130,13 +3132,6 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, } head->func = func; head->next = NULL; - - /* - * Opportunistically note grace-period endings and beginnings. - * Note that we might see a beginning right after we see an - * end, but never vice versa, since this CPU has to pass through - * a quiescent state betweentimes. - */ local_irq_save(flags); rdp = this_cpu_ptr(rsp->rda); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index e99a5234d9ed..fe98dd24adf8 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -404,6 +404,7 @@ struct rcu_data { 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. */ + int exp_dynticks_snap; /* Double-check need for IPI. */ /* 7) Callback offloading. */ #ifdef CONFIG_RCU_NOCB_CPU diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 24343eb87b58..d3053e99fdb6 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -358,8 +358,10 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp, struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); + rdp->exp_dynticks_snap = + atomic_add_return(0, &rdtp->dynticks); if (raw_smp_processor_id() == cpu || - !(atomic_add_return(0, &rdtp->dynticks) & 0x1) || + !(rdp->exp_dynticks_snap & 0x1) || !(rnp->qsmaskinitnext & rdp->grpmask)) mask_ofl_test |= rdp->grpmask; } @@ -377,9 +379,17 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp, /* IPI the remaining CPUs for expedited quiescent state. */ for_each_leaf_node_possible_cpu(rnp, cpu) { unsigned long mask = leaf_node_cpu_bit(rnp, cpu); + struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); + struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); + if (!(mask_ofl_ipi & mask)) continue; retry_ipi: + if (atomic_add_return(0, &rdtp->dynticks) != + rdp->exp_dynticks_snap) { + mask_ofl_test |= mask; + continue; + } ret = smp_call_function_single(cpu, func, rsp, 0); if (!ret) { mask_ofl_ipi &= ~mask; |