diff options
Diffstat (limited to 'sys/kern/kern_lock.c')
| -rw-r--r-- | sys/kern/kern_lock.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c index e9cff2e..c0b929a 100644 --- a/sys/kern/kern_lock.c +++ b/sys/kern/kern_lock.c @@ -589,6 +589,34 @@ lockmgr_printinfo(lkp) } #ifdef DDB +/* + * Check to see if a thread that is blocked on a sleep queue is actually + * blocked on a 'struct lock'. If so, output some details and return true. + * If the lock has an exclusive owner, return that in *ownerp. + */ +int +lockmgr_chain(struct thread *td, struct thread **ownerp) +{ + struct lock *lkp; + + lkp = td->td_wchan; + + /* Simple test to see if wchan points to a lockmgr lock. */ + if (lkp->lk_wmesg != td->td_wmesg) + return (0); + + /* Ok, we think we have a lockmgr lock, so output some details. */ + db_printf("blocked on lk \"%s\" ", lkp->lk_wmesg); + if (lkp->lk_sharecount) { + db_printf("SHARED (count %d)\n", lkp->lk_sharecount); + *ownerp = NULL; + } else { + db_printf("EXCL (count %d)\n", lkp->lk_exclusivecount); + *ownerp = lkp->lk_lockholder; + } + return (1); +} + DB_SHOW_COMMAND(lockmgr, db_show_lockmgr) { struct thread *td; |
