diff options
| -rw-r--r-- | include/linux/torture.h | 7 | ||||
| -rw-r--r-- | kernel/rcu/rcutorture.c | 69 | ||||
| -rw-r--r-- | kernel/torture.c | 87 |
3 files changed, 104 insertions, 59 deletions
diff --git a/include/linux/torture.h b/include/linux/torture.h index 0259db3..203f127 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -75,8 +75,13 @@ int torture_shuffle_init(long shuffint); /* Shutdown task absorption, for when the tasks cannot safely be killed. */ void torture_shutdown_absorb(const char *title); +/* Task stuttering, which forces load/no-load transitions. */ +void stutter_wait(const char *title); +int torture_stutter_init(int s); +void torture_stutter_cleanup(void); + /* Initialization and cleanup. */ -void torture_init_begin(char *ttype, bool v); +void torture_init_begin(char *ttype, bool v, int *runnable); void torture_init_end(void); bool torture_cleanup(void); bool torture_must_stop(void); diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 9357c88..4329ad1 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -103,7 +103,6 @@ static struct task_struct *writer_task; static struct task_struct **fakewriter_tasks; static struct task_struct **reader_tasks; static struct task_struct *stats_task; -static struct task_struct *stutter_task; static struct task_struct *fqs_task; static struct task_struct *boost_tasks[NR_CPUS]; static struct task_struct *shutdown_task; @@ -145,8 +144,6 @@ static long n_barrier_attempts; static long n_barrier_successes; static struct list_head rcu_torture_removed; -static int stutter_pause_test; - #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) #define RCUTORTURE_RUNNABLE_INIT 1 #else @@ -222,18 +219,6 @@ rcu_torture_free(struct rcu_torture *p) spin_unlock_bh(&rcu_torture_lock); } -static void -rcu_stutter_wait(const char *title) -{ - while (stutter_pause_test || !rcutorture_runnable) { - if (rcutorture_runnable) - schedule_timeout_interruptible(1); - else - schedule_timeout_interruptible(round_jiffies_relative(HZ)); - torture_shutdown_absorb(title); - } -} - /* * Operations vector for selecting different types of tests. */ @@ -571,7 +556,7 @@ static int rcu_torture_boost(void *arg) oldstarttime = boost_starttime; while (ULONG_CMP_LT(jiffies, oldstarttime)) { schedule_timeout_interruptible(oldstarttime - jiffies); - rcu_stutter_wait("rcu_torture_boost"); + stutter_wait("rcu_torture_boost"); if (torture_must_stop()) goto checkwait; } @@ -593,7 +578,7 @@ static int rcu_torture_boost(void *arg) call_rcu_time = jiffies; } cond_resched(); - rcu_stutter_wait("rcu_torture_boost"); + stutter_wait("rcu_torture_boost"); if (torture_must_stop()) goto checkwait; } @@ -618,7 +603,7 @@ static int rcu_torture_boost(void *arg) } /* Go do the stutter. */ -checkwait: rcu_stutter_wait("rcu_torture_boost"); +checkwait: stutter_wait("rcu_torture_boost"); } while (!torture_must_stop()); /* Clean up and exit. */ @@ -656,7 +641,7 @@ rcu_torture_fqs(void *arg) udelay(fqs_holdoff); fqs_burst_remaining -= fqs_holdoff; } - rcu_stutter_wait("rcu_torture_fqs"); + stutter_wait("rcu_torture_fqs"); } while (!torture_must_stop()); VERBOSE_TOROUT_STRING("rcu_torture_fqs task stopping"); torture_shutdown_absorb("rcu_torture_fqs"); @@ -728,7 +713,7 @@ rcu_torture_writer(void *arg) } } rcutorture_record_progress(++rcu_torture_current_version); - rcu_stutter_wait("rcu_torture_writer"); + stutter_wait("rcu_torture_writer"); } while (!torture_must_stop()); VERBOSE_TOROUT_STRING("rcu_torture_writer task stopping"); torture_shutdown_absorb("rcu_torture_writer"); @@ -765,7 +750,7 @@ rcu_torture_fakewriter(void *arg) } else { cur_ops->exp_sync(); } - rcu_stutter_wait("rcu_torture_fakewriter"); + stutter_wait("rcu_torture_fakewriter"); } while (!torture_must_stop()); VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task stopping"); @@ -910,7 +895,7 @@ rcu_torture_reader(void *arg) preempt_enable(); cur_ops->readunlock(idx); schedule(); - rcu_stutter_wait("rcu_torture_reader"); + stutter_wait("rcu_torture_reader"); } while (!torture_must_stop()); VERBOSE_TOROUT_STRING("rcu_torture_reader task stopping"); torture_shutdown_absorb("rcu_torture_reader"); @@ -1034,25 +1019,6 @@ rcu_torture_stats(void *arg) return 0; } -/* Cause the rcutorture test to "stutter", starting and stopping all - * threads periodically. - */ -static int -rcu_torture_stutter(void *arg) -{ - VERBOSE_TOROUT_STRING("rcu_torture_stutter task started"); - do { - schedule_timeout_interruptible(stutter * HZ); - stutter_pause_test = 1; - if (!kthread_should_stop()) - schedule_timeout_interruptible(stutter * HZ); - stutter_pause_test = 0; - torture_shutdown_absorb("rcu_torture_stutter"); - } while (!kthread_should_stop()); - VERBOSE_TOROUT_STRING("rcu_torture_stutter task stopping"); - return 0; -} - static inline void rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) { @@ -1403,11 +1369,7 @@ rcu_torture_cleanup(void) rcu_torture_barrier_cleanup(); rcu_torture_stall_cleanup(); - if (stutter_task) { - VERBOSE_TOROUT_STRING("Stopping rcu_torture_stutter task"); - kthread_stop(stutter_task); - } - stutter_task = NULL; + torture_stutter_cleanup(); if (writer_task) { VERBOSE_TOROUT_STRING("Stopping rcu_torture_writer task"); @@ -1548,7 +1510,7 @@ rcu_torture_init(void) &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops, }; - torture_init_begin(torture_type, verbose); + torture_init_begin(torture_type, verbose, &rcutorture_runnable); /* Process args and tell the world that the torturer is on the job. */ for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { @@ -1682,21 +1644,14 @@ rcu_torture_init(void) if (stutter < 0) stutter = 0; if (stutter) { - /* Create the stutter thread */ - stutter_task = kthread_run(rcu_torture_stutter, NULL, - "rcu_torture_stutter"); - if (IS_ERR(stutter_task)) { - firsterr = PTR_ERR(stutter_task); - VERBOSE_TOROUT_ERRSTRING("Failed to create stutter"); - stutter_task = NULL; + firsterr = torture_stutter_init(stutter * HZ); + if (firsterr) goto unwind; - } - torture_shuffle_task_register(stutter_task); } if (fqs_duration < 0) fqs_duration = 0; if (fqs_duration) { - /* Create the stutter thread */ + /* Create the fqs thread */ fqs_task = kthread_run(rcu_torture_fqs, NULL, "rcu_torture_fqs"); if (IS_ERR(fqs_task)) { diff --git a/kernel/torture.c b/kernel/torture.c index d51de30..b30c2ee 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -58,6 +58,7 @@ static bool verbose; #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ static int fullstop = FULLSTOP_RMMOD; static DEFINE_MUTEX(fullstop_mutex); +static int *torture_runnable; #ifdef CONFIG_HOTPLUG_CPU @@ -453,16 +454,100 @@ static struct notifier_block torture_shutdown_nb = { }; /* + * Variables for stuttering, which means to periodically pause and + * restart testing in order to catch bugs that appear when load is + * suddenly applied to or removed from the system. + */ +static struct task_struct *stutter_task; +static int stutter_pause_test; +static int stutter; + +/* + * Block until the stutter interval ends. This must be called periodically + * by all running kthreads that need to be subject to stuttering. + */ +void stutter_wait(const char *title) +{ + while (ACCESS_ONCE(stutter_pause_test) || + (torture_runnable && !ACCESS_ONCE(*torture_runnable))) { + if (stutter_pause_test) + schedule_timeout_interruptible(1); + else + schedule_timeout_interruptible(round_jiffies_relative(HZ)); + torture_shutdown_absorb(title); + } +} +EXPORT_SYMBOL_GPL(stutter_wait); + +/* + * Cause the torture test to "stutter", starting and stopping all + * threads periodically. + */ +static int torture_stutter(void *arg) +{ + VERBOSE_TOROUT_STRING("torture_stutter task started"); + do { + if (!torture_must_stop()) { + schedule_timeout_interruptible(stutter); + ACCESS_ONCE(stutter_pause_test) = 1; + } + if (!torture_must_stop()) + schedule_timeout_interruptible(stutter); + ACCESS_ONCE(stutter_pause_test) = 0; + torture_shutdown_absorb("torture_stutter"); + } while (!torture_must_stop()); + VERBOSE_TOROUT_STRING("torture_stutter task stopping"); + return 0; +} + +/* + * Initialize and kick off the torture_stutter kthread. + */ +int torture_stutter_init(int s) +{ + int ret; + + stutter = s; + stutter_task = kthread_run(torture_stutter, NULL, "torture_stutter"); + if (IS_ERR(stutter_task)) { + ret = PTR_ERR(stutter_task); + VERBOSE_TOROUT_ERRSTRING("Failed to create stutter"); + stutter_task = NULL; + return ret; + } + torture_shuffle_task_register(stutter_task); + return 0; +} +EXPORT_SYMBOL_GPL(torture_stutter_init); + +/* + * Cleanup after the torture_stutter kthread. + */ +void torture_stutter_cleanup(void) +{ + if (!stutter_task) + return; + VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); + kthread_stop(stutter_task); + stutter_task = NULL; +} +EXPORT_SYMBOL_GPL(torture_stutter_cleanup); + +/* * Initialize torture module. Please note that this is -not- invoked via * the usual module_init() mechanism, but rather by an explicit call from * the client torture module. This call must be paired with a later * torture_init_end(). + * + * The runnable parameter points to a flag that controls whether or not + * the test is currently runnable. If there is no such flag, pass in NULL. */ -void __init torture_init_begin(char *ttype, bool v) +void __init torture_init_begin(char *ttype, bool v, int *runnable) { mutex_lock(&fullstop_mutex); torture_type = ttype; verbose = v; + torture_runnable = runnable; fullstop = FULLSTOP_DONTSTOP; } |
