From e34191fad8e5d9fe4e76f6d03b5e29e3eae7535a Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Mon, 29 Sep 2014 06:14:23 -0700 Subject: locktorture: Support rwlocks Add a "rw_lock" torture test to stress kernel rwlocks and their irq variant. Reader critical regions are 5x longer than writers. As such a similar ratio of lock acquisitions is seen in the statistics. In the case of massive contention, both hold the lock for 1/10 of a second. Signed-off-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney --- kernel/locking/locktorture.c | 115 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 112 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 540d5dfe1112..0762b25b4110 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -229,6 +230,110 @@ 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) @@ -535,8 +640,11 @@ 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 +679,8 @@ 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 -- cgit v1.2.3