diff options
| -rw-r--r-- | kernel/rcutorture.c | 113 |
1 files changed, 68 insertions, 45 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 1cff28db56b6..7c4142a79f0a 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -136,29 +136,47 @@ static int stutter_pause_test = 0; #endif int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; -#define FULLSTOP_SHUTDOWN 1 /* Bail due to system shutdown/panic. */ -#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */ -static int fullstop; /* stop generating callbacks at test end. */ -DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */ - /* spawning of kthreads. */ +/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ + +#define FULLSTOP_DONTSTOP 0 /* Normal operation. */ +#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ +#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ +static int fullstop = FULLSTOP_RMMOD; +DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */ + /* of kthreads. */ /* - * Detect and respond to a signal-based shutdown. + * Detect and respond to a system shutdown. */ static int rcutorture_shutdown_notify(struct notifier_block *unused1, unsigned long unused2, void *unused3) { - if (fullstop) - return NOTIFY_DONE; mutex_lock(&fullstop_mutex); - if (!fullstop) + if (fullstop == FULLSTOP_DONTSTOP) fullstop = FULLSTOP_SHUTDOWN; + else + printk(KERN_WARNING /* but going down anyway, so... */ + "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); mutex_unlock(&fullstop_mutex); return NOTIFY_DONE; } /* + * Absorb kthreads into a kernel function that won't return, so that + * they won't ever access module text or data again. + */ +static void rcutorture_shutdown_absorb(char *title) +{ + if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { + printk(KERN_NOTICE + "rcutorture thread %s parking due to system shutdown\n", + title); + schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); + } +} + +/* * Allocate an element from the rcu_tortures pool. */ static struct rcu_torture * @@ -219,13 +237,14 @@ rcu_random(struct rcu_random_state *rrsp) } static void -rcu_stutter_wait(void) +rcu_stutter_wait(char *title) { - while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) { + while (stutter_pause_test || !rcutorture_runnable) { if (rcutorture_runnable) schedule_timeout_interruptible(1); else schedule_timeout_interruptible(round_jiffies_relative(HZ)); + rcutorture_shutdown_absorb(title); } } @@ -287,7 +306,7 @@ rcu_torture_cb(struct rcu_head *p) int i; struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); - if (fullstop) { + if (fullstop != FULLSTOP_DONTSTOP) { /* Test is ending, just drop callbacks on the floor. */ /* The next initialization will pick up the pieces. */ return; @@ -619,10 +638,11 @@ rcu_torture_writer(void *arg) } rcu_torture_current_version++; oldbatch = cur_ops->completed(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_writer"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + rcutorture_shutdown_absorb("rcu_torture_writer"); + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -643,11 +663,12 @@ rcu_torture_fakewriter(void *arg) schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); udelay(rcu_random(&rand) & 0x3ff); cur_ops->sync(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_fakewriter"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + rcutorture_shutdown_absorb("rcu_torture_fakewriter"); + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -752,12 +773,13 @@ rcu_torture_reader(void *arg) preempt_enable(); cur_ops->readunlock(idx); schedule(); - rcu_stutter_wait(); - } while (!kthread_should_stop() && !fullstop); + rcu_stutter_wait("rcu_torture_reader"); + } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); + rcutorture_shutdown_absorb("rcu_torture_reader"); if (irqreader && cur_ops->irqcapable) del_timer_sync(&t); - while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN) + while (!kthread_should_stop()) schedule_timeout_uninterruptible(1); return 0; } @@ -854,7 +876,8 @@ rcu_torture_stats(void *arg) do { schedule_timeout_interruptible(stat_interval * HZ); rcu_torture_stats_print(); - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_stats"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); return 0; } @@ -866,52 +889,49 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ */ static void rcu_torture_shuffle_tasks(void) { - cpumask_var_t tmp_mask; + cpumask_t tmp_mask; int i; - if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL)) - BUG(); - - cpumask_setall(tmp_mask); + cpus_setall(tmp_mask); get_online_cpus(); /* No point in shuffling if there is only one online CPU (ex: UP) */ - if (num_online_cpus() == 1) - goto out; + if (num_online_cpus() == 1) { + put_online_cpus(); + return; + } if (rcu_idle_cpu != -1) - cpumask_clear_cpu(rcu_idle_cpu, tmp_mask); + cpu_clear(rcu_idle_cpu, tmp_mask); - set_cpus_allowed_ptr(current, tmp_mask); + set_cpus_allowed_ptr(current, &tmp_mask); if (reader_tasks) { for (i = 0; i < nrealreaders; i++) if (reader_tasks[i]) set_cpus_allowed_ptr(reader_tasks[i], - tmp_mask); + &tmp_mask); } if (fakewriter_tasks) { for (i = 0; i < nfakewriters; i++) if (fakewriter_tasks[i]) set_cpus_allowed_ptr(fakewriter_tasks[i], - tmp_mask); + &tmp_mask); } if (writer_task) - set_cpus_allowed_ptr(writer_task, tmp_mask); + set_cpus_allowed_ptr(writer_task, &tmp_mask); if (stats_task) - set_cpus_allowed_ptr(stats_task, tmp_mask); + set_cpus_allowed_ptr(stats_task, &tmp_mask); if (rcu_idle_cpu == -1) rcu_idle_cpu = num_online_cpus() - 1; else rcu_idle_cpu--; -out: put_online_cpus(); - free_cpumask_var(tmp_mask); } /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the @@ -925,7 +945,8 @@ rcu_torture_shuffle(void *arg) do { schedule_timeout_interruptible(shuffle_interval * HZ); rcu_torture_shuffle_tasks(); - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_shuffle"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); return 0; } @@ -940,10 +961,11 @@ rcu_torture_stutter(void *arg) do { schedule_timeout_interruptible(stutter * HZ); stutter_pause_test = 1; - if (!kthread_should_stop() && !fullstop) + if (!kthread_should_stop()) schedule_timeout_interruptible(stutter * HZ); stutter_pause_test = 0; - } while (!kthread_should_stop() && !fullstop); + rcutorture_shutdown_absorb("rcu_torture_stutter"); + } while (!kthread_should_stop()); VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); return 0; } @@ -970,15 +992,16 @@ rcu_torture_cleanup(void) int i; mutex_lock(&fullstop_mutex); - if (!fullstop) { - /* If being signaled, let it happen, then exit. */ + if (fullstop == FULLSTOP_SHUTDOWN) { + printk(KERN_WARNING /* but going down anyway, so... */ + "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); mutex_unlock(&fullstop_mutex); - schedule_timeout_interruptible(10 * HZ); + schedule_timeout_uninterruptible(10); if (cur_ops->cb_barrier != NULL) cur_ops->cb_barrier(); return; } - fullstop = FULLSTOP_CLEANUP; + fullstop = FULLSTOP_RMMOD; mutex_unlock(&fullstop_mutex); unregister_reboot_notifier(&rcutorture_nb); if (stutter_task) { @@ -1078,7 +1101,7 @@ rcu_torture_init(void) else nrealreaders = 2 * num_online_cpus(); rcu_torture_print_module_parms("Start of test"); - fullstop = 0; + fullstop = FULLSTOP_DONTSTOP; /* Set up the freelist. */ |