diff options
Diffstat (limited to 'sys/kern/kern_rmlock.c')
-rw-r--r-- | sys/kern/kern_rmlock.c | 61 |
1 files changed, 44 insertions, 17 deletions
diff --git a/sys/kern/kern_rmlock.c b/sys/kern/kern_rmlock.c index ff397eb..ec0e7fa 100644 --- a/sys/kern/kern_rmlock.c +++ b/sys/kern/kern_rmlock.c @@ -77,11 +77,11 @@ static void assert_rm(const struct lock_object *lock, int what); #ifdef DDB static void db_show_rm(const struct lock_object *lock); #endif -static void lock_rm(struct lock_object *lock, int how); +static void lock_rm(struct lock_object *lock, uintptr_t how); #ifdef KDTRACE_HOOKS static int owner_rm(const struct lock_object *lock, struct thread **owner); #endif -static int unlock_rm(struct lock_object *lock); +static uintptr_t unlock_rm(struct lock_object *lock); struct lock_class lock_class_rm = { .lc_name = "rm", @@ -118,34 +118,61 @@ assert_rm(const struct lock_object *lock, int what) rm_assert((const struct rmlock *)lock, what); } -/* - * These do not support read locks because it would be hard to make - * the tracker work correctly with the current lock_class API as you - * would need to have the tracker pointer available when calling - * rm_rlock() in lock_rm(). - */ static void -lock_rm(struct lock_object *lock, int how) +lock_rm(struct lock_object *lock, uintptr_t how) { struct rmlock *rm; + struct rm_priotracker *tracker; rm = (struct rmlock *)lock; - if (how) + if (how == 0) rm_wlock(rm); -#ifdef INVARIANTS - else - panic("lock_rm called in read mode"); -#endif + else { + tracker = (struct rm_priotracker *)how; + rm_rlock(rm, tracker); + } } -static int +static uintptr_t unlock_rm(struct lock_object *lock) { + struct thread *td; + struct pcpu *pc; struct rmlock *rm; + struct rm_queue *queue; + struct rm_priotracker *tracker; + uintptr_t how; rm = (struct rmlock *)lock; - rm_wunlock(rm); - return (1); + tracker = NULL; + how = 0; + rm_assert(rm, RA_LOCKED | RA_NOTRECURSED); + if (rm_wowned(rm)) + rm_wunlock(rm); + else { + /* + * Find the right rm_priotracker structure for curthread. + * The guarantee about its uniqueness is given by the fact + * we already asserted the lock wasn't recursively acquired. + */ + critical_enter(); + td = curthread; + pc = pcpu_find(curcpu); + for (queue = pc->pc_rm_queue.rmq_next; + queue != &pc->pc_rm_queue; queue = queue->rmq_next) { + tracker = (struct rm_priotracker *)queue; + if ((tracker->rmp_rmlock == rm) && + (tracker->rmp_thread == td)) { + how = (uintptr_t)tracker; + break; + } + } + KASSERT(tracker != NULL, + ("rm_priotracker is non-NULL when lock held in read mode")); + critical_exit(); + rm_runlock(rm, tracker); + } + return (how); } #ifdef KDTRACE_HOOKS |