diff --git a/Documentation/locking/locktorture.txt b/Documentation/locking/locktorture.txt index be715015e0f7..619f2bb136a5 100644 --- a/Documentation/locking/locktorture.txt +++ b/Documentation/locking/locktorture.txt @@ -45,6 +45,11 @@ torture_type Type of lock to torture. By default, only spinlocks will o "spin_lock_irq": spin_lock_irq() and spin_unlock_irq() pairs. + o "rw_lock": read/write lock() and unlock() rwlock pairs. + + o "rw_lock_irq": read/write lock_irq() and unlock_irq() + rwlock pairs. + o "mutex_lock": mutex_lock() and mutex_unlock() pairs. o "rwsem_lock": read/write down() and up() semaphore pairs. diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 540d5dfe1112..ec8cce259779 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -20,31 +20,20 @@ * Author: Paul E. McKenney * Based on kernel/rcu/torture.c. */ -#include #include -#include #include #include -#include #include +#include #include +#include #include #include #include #include -#include -#include #include -#include -#include -#include -#include -#include #include -#include #include -#include -#include #include MODULE_LICENSE("GPL"); @@ -204,7 +193,7 @@ static struct lock_torture_ops spin_lock_ops = { }; static int torture_spin_lock_write_lock_irq(void) -__acquires(torture_spinlock_irq) +__acquires(torture_spinlock) { unsigned long flags; @@ -229,6 +218,110 @@ static struct lock_torture_ops spin_lock_irq_ops = { .name = "spin_lock_irq" }; +static DEFINE_RWLOCK(torture_rwlock); + +static int torture_rwlock_write_lock(void) __acquires(torture_rwlock) +{ + write_lock(&torture_rwlock); + return 0; +} + +static void torture_rwlock_write_delay(struct torture_random_state *trsp) +{ + const unsigned long shortdelay_us = 2; + const unsigned long longdelay_ms = 100; + + /* We want a short delay mostly to emulate likely code, and + * we want a long delay occasionally to force massive contention. + */ + if (!(torture_random(trsp) % + (cxt.nrealwriters_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms); + else + udelay(shortdelay_us); +} + +static void torture_rwlock_write_unlock(void) __releases(torture_rwlock) +{ + write_unlock(&torture_rwlock); +} + +static int torture_rwlock_read_lock(void) __acquires(torture_rwlock) +{ + read_lock(&torture_rwlock); + return 0; +} + +static void torture_rwlock_read_delay(struct torture_random_state *trsp) +{ + const unsigned long shortdelay_us = 10; + const unsigned long longdelay_ms = 100; + + /* We want a short delay mostly to emulate likely code, and + * we want a long delay occasionally to force massive contention. + */ + if (!(torture_random(trsp) % + (cxt.nrealreaders_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms); + else + udelay(shortdelay_us); +} + +static void torture_rwlock_read_unlock(void) __releases(torture_rwlock) +{ + read_unlock(&torture_rwlock); +} + +static struct lock_torture_ops rw_lock_ops = { + .writelock = torture_rwlock_write_lock, + .write_delay = torture_rwlock_write_delay, + .writeunlock = torture_rwlock_write_unlock, + .readlock = torture_rwlock_read_lock, + .read_delay = torture_rwlock_read_delay, + .readunlock = torture_rwlock_read_unlock, + .name = "rw_lock" +}; + +static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock) +{ + unsigned long flags; + + write_lock_irqsave(&torture_rwlock, flags); + cxt.cur_ops->flags = flags; + return 0; +} + +static void torture_rwlock_write_unlock_irq(void) +__releases(torture_rwlock) +{ + write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); +} + +static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) +{ + unsigned long flags; + + read_lock_irqsave(&torture_rwlock, flags); + cxt.cur_ops->flags = flags; + return 0; +} + +static void torture_rwlock_read_unlock_irq(void) +__releases(torture_rwlock) +{ + write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); +} + +static struct lock_torture_ops rw_lock_irq_ops = { + .writelock = torture_rwlock_write_lock_irq, + .write_delay = torture_rwlock_write_delay, + .writeunlock = torture_rwlock_write_unlock_irq, + .readlock = torture_rwlock_read_lock_irq, + .read_delay = torture_rwlock_read_delay, + .readunlock = torture_rwlock_read_unlock_irq, + .name = "rw_lock_irq" +}; + static DEFINE_MUTEX(torture_mutex); static int torture_mutex_lock(void) __acquires(torture_mutex) @@ -348,14 +441,19 @@ static int lock_torture_writer(void *arg) do { if ((torture_random(&rand) & 0xfffff) == 0) schedule_timeout_uninterruptible(1); + cxt.cur_ops->writelock(); if (WARN_ON_ONCE(lock_is_write_held)) lwsp->n_lock_fail++; lock_is_write_held = 1; + if (WARN_ON_ONCE(lock_is_read_held)) + lwsp->n_lock_fail++; /* rare, but... */ + lwsp->n_lock_acquired++; cxt.cur_ops->write_delay(&rand); lock_is_write_held = 0; cxt.cur_ops->writeunlock(); + stutter_wait("lock_torture_writer"); } while (!torture_must_stop()); torture_kthread_stopping("lock_torture_writer"); @@ -377,12 +475,17 @@ static int lock_torture_reader(void *arg) do { if ((torture_random(&rand) & 0xfffff) == 0) schedule_timeout_uninterruptible(1); + cxt.cur_ops->readlock(); lock_is_read_held = 1; + if (WARN_ON_ONCE(lock_is_write_held)) + lrsp->n_lock_fail++; /* rare, but... */ + lrsp->n_lock_acquired++; cxt.cur_ops->read_delay(&rand); lock_is_read_held = 0; cxt.cur_ops->readunlock(); + stutter_wait("lock_torture_reader"); } while (!torture_must_stop()); torture_kthread_stopping("lock_torture_reader"); @@ -535,8 +638,11 @@ static int __init lock_torture_init(void) int i, j; int firsterr = 0; static struct lock_torture_ops *torture_ops[] = { - &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops, - &mutex_lock_ops, &rwsem_lock_ops, + &lock_busted_ops, + &spin_lock_ops, &spin_lock_irq_ops, + &rw_lock_ops, &rw_lock_irq_ops, + &mutex_lock_ops, + &rwsem_lock_ops, }; if (!torture_init_begin(torture_type, verbose, &torture_runnable)) @@ -571,7 +677,8 @@ static int __init lock_torture_init(void) cxt.debug_lock = true; #endif #ifdef CONFIG_DEBUG_SPINLOCK - if (strncmp(torture_type, "spin", 4) == 0) + if ((strncmp(torture_type, "spin", 4) == 0) || + (strncmp(torture_type, "rw_lock", 7) == 0)) cxt.debug_lock = true; #endif diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5dbe22aa3efd..09b685daee3d 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2043,9 +2043,10 @@ __acquires(&pool->lock) * kernels, where a requeueing work item waiting for something to * happen could deadlock with stop_machine as such work item could * indefinitely requeue itself while all other CPUs are trapped in - * stop_machine. + * stop_machine. At the same time, report a quiescent RCU state so + * the same condition doesn't freeze RCU. */ - cond_resched(); + cond_resched_rcu_qs(); spin_lock_irq(&pool->lock); diff --git a/tools/testing/selftests/rcutorture/configs/lock/CFLIST b/tools/testing/selftests/rcutorture/configs/lock/CFLIST index 6108137da770..6910b7370761 100644 --- a/tools/testing/selftests/rcutorture/configs/lock/CFLIST +++ b/tools/testing/selftests/rcutorture/configs/lock/CFLIST @@ -1,3 +1,4 @@ LOCK01 LOCK02 LOCK03 +LOCK04 \ No newline at end of file diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK04 b/tools/testing/selftests/rcutorture/configs/lock/LOCK04 new file mode 100644 index 000000000000..1d1da1477fc3 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK04 @@ -0,0 +1,6 @@ +CONFIG_SMP=y +CONFIG_NR_CPUS=4 +CONFIG_HOTPLUG_CPU=y +CONFIG_PREEMPT_NONE=n +CONFIG_PREEMPT_VOLUNTARY=n +CONFIG_PREEMPT=y diff --git a/tools/testing/selftests/rcutorture/configs/lock/LOCK04.boot b/tools/testing/selftests/rcutorture/configs/lock/LOCK04.boot new file mode 100644 index 000000000000..48c04fe47fb4 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/lock/LOCK04.boot @@ -0,0 +1 @@ +locktorture.torture_type=rw_lock