diff options
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 489b62a67d35..06e40dd53b23 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -196,7 +196,7 @@ void rcu_note_context_switch(int cpu) EXPORT_SYMBOL_GPL(rcu_note_context_switch); DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { - .dynticks_nesting = LLONG_MAX / 2, + .dynticks_nesting = DYNTICK_TASK_NESTING, .dynticks = ATOMIC_INIT(1), }; @@ -348,17 +348,17 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) * we really have entered idle, and must do the appropriate accounting. * The caller must have disabled interrupts. */ -static void rcu_idle_enter_common(struct rcu_dynticks *rdtp) +static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval) { if (rdtp->dynticks_nesting) { - trace_rcu_dyntick("--=", rdtp->dynticks_nesting); + trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting); return; } - trace_rcu_dyntick("Start", rdtp->dynticks_nesting); + trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting); if (!idle_cpu(smp_processor_id())) { WARN_ON_ONCE(1); /* must be idle task! */ trace_rcu_dyntick("Error on entry: not idle task", - rdtp->dynticks_nesting); + oldval, rdtp->dynticks_nesting); ftrace_dump(DUMP_ALL); } /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */ @@ -383,12 +383,14 @@ static void rcu_idle_enter_common(struct rcu_dynticks *rdtp) void rcu_idle_enter(void) { unsigned long flags; + long long oldval; struct rcu_dynticks *rdtp; local_irq_save(flags); rdtp = &__get_cpu_var(rcu_dynticks); + oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting = 0; - rcu_idle_enter_common(rdtp); + rcu_idle_enter_common(rdtp, oldval); local_irq_restore(flags); } @@ -411,13 +413,15 @@ void rcu_idle_enter(void) void rcu_irq_exit(void) { unsigned long flags; + long long oldval; struct rcu_dynticks *rdtp; local_irq_save(flags); rdtp = &__get_cpu_var(rcu_dynticks); + oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting--; WARN_ON_ONCE(rdtp->dynticks_nesting < 0); - rcu_idle_enter_common(rdtp); + rcu_idle_enter_common(rdtp, oldval); local_irq_restore(flags); } @@ -431,7 +435,7 @@ void rcu_irq_exit(void) static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval) { if (oldval) { - trace_rcu_dyntick("++=", rdtp->dynticks_nesting); + trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting); return; } smp_mb__before_atomic_inc(); /* Force ordering w/previous sojourn. */ @@ -439,10 +443,11 @@ static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval) /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */ smp_mb__after_atomic_inc(); /* See above. */ WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1)); - trace_rcu_dyntick("End", oldval); + trace_rcu_dyntick("End", oldval, rdtp->dynticks_nesting); if (!idle_cpu(smp_processor_id())) { WARN_ON_ONCE(1); /* must be idle task! */ - trace_rcu_dyntick("Error on exit: not idle task", oldval); + trace_rcu_dyntick("Error on exit: not idle task", + oldval, rdtp->dynticks_nesting); ftrace_dump(DUMP_ALL); } } @@ -453,8 +458,8 @@ static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval) * Exit idle mode, in other words, -enter- the mode in which RCU * read-side critical sections can occur. * - * We crowbar the ->dynticks_nesting field to LLONG_MAX/2 to allow for - * the possibility of usermode upcalls messing up our count + * We crowbar the ->dynticks_nesting field to DYNTICK_TASK_NESTING to + * allow for the possibility of usermode upcalls messing up our count * of interrupt nesting level during the busy period that is just * now starting. */ @@ -468,7 +473,7 @@ void rcu_idle_exit(void) rdtp = &__get_cpu_var(rcu_dynticks); oldval = rdtp->dynticks_nesting; WARN_ON_ONCE(oldval != 0); - rdtp->dynticks_nesting = LLONG_MAX / 2; + rdtp->dynticks_nesting = DYNTICK_TASK_NESTING; rcu_idle_exit_common(rdtp, oldval); local_irq_restore(flags); } @@ -2012,7 +2017,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->nxttail[i] = &rdp->nxtlist; rdp->qlen = 0; rdp->dynticks = &per_cpu(rcu_dynticks, cpu); - WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != LLONG_MAX / 2); + WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_NESTING); WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1); rdp->cpu = cpu; rdp->rsp = rsp; @@ -2040,7 +2045,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) rdp->qlen_last_fqs_check = 0; rdp->n_force_qs_snap = rsp->n_force_qs; rdp->blimit = blimit; - WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != LLONG_MAX / 2); + WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_NESTING); WARN_ON_ONCE((atomic_read(&rdp->dynticks->dynticks) & 0x1) != 1); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ |