diff options
| -rw-r--r-- | sys/kern/subr_turnstile.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c index 16562f8..2c3e34b 100644 --- a/sys/kern/subr_turnstile.c +++ b/sys/kern/subr_turnstile.c @@ -76,6 +76,7 @@ __FBSDID("$FreeBSD$"); #include <sys/turnstile.h> #ifdef DDB +#include <sys/kdb.h> #include <ddb/ddb.h> #endif @@ -1033,4 +1034,141 @@ found: print_queue(&ts->ts_pending, "Pending Threads", "\t"); } + +static void +print_threadchain(struct thread *td, const char *prefix) +{ + struct lock_object *lock; + struct lock_class *class; + struct turnstile *ts; + + /* + * Follow the chain. We keep walking as long as the thread is + * blocked on a turnstile that has an owner. + */ + for (;;) { + db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, + td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : + td->td_proc->p_comm); + switch (td->td_state) { + case TDS_INACTIVE: + db_printf("is inactive\n"); + return; + case TDS_CAN_RUN: + db_printf("can run\n"); + return; + case TDS_RUNQ: + db_printf("is on a run queue\n"); + return; + case TDS_RUNNING: + db_printf("running on CPU %d\n", td->td_oncpu); + return; + case TDS_INHIBITED: + if (TD_ON_LOCK(td)) { + ts = td->td_blocked; + lock = ts->ts_lockobj; + class = LOCK_CLASS(lock); + db_printf("blocked on lock %p (%s) \"%s\"\n", + lock, class->lc_name, lock->lo_name); + if (ts->ts_owner == NULL) + return; + td = ts->ts_owner; + break; + } + db_printf("inhibited\n"); + return; + default: + db_printf("??? (%#x)\n", td->td_state); + return; + } + } +} + +DB_SHOW_COMMAND(threadchain, db_show_threadchain) +{ + struct thread *td; + + /* Figure out which thread to start with. */ + if (have_addr) + td = db_lookup_thread(addr, TRUE); + else + td = kdb_thread; + + print_threadchain(td, ""); +} + +DB_SHOW_COMMAND(allchains, db_show_allchains) +{ + struct thread *td; + struct proc *p; + int i; + + i = 1; + LIST_FOREACH(p, &allproc, p_list) { + FOREACH_THREAD_IN_PROC(p, td) { + if (TD_ON_LOCK(td) && LIST_EMPTY(&td->td_contested)) { + db_printf("chain %d:\n", i++); + print_threadchain(td, " "); + } + } + } +} + +static void print_waiters(struct turnstile *ts, int indent); + +static void +print_waiter(struct thread *td, int indent) +{ + struct turnstile *ts; + int i; + + for (i = 0; i < indent; i++) + db_printf(" "); + print_thread(td, "thread "); + LIST_FOREACH(ts, &td->td_contested, ts_link) + print_waiters(ts, indent + 1); +} + +static void +print_waiters(struct turnstile *ts, int indent) +{ + struct lock_object *lock; + struct lock_class *class; + struct thread *td; + int i; + + lock = ts->ts_lockobj; + class = LOCK_CLASS(lock); + for (i = 0; i < indent; i++) + db_printf(" "); + db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, lock->lo_name); + TAILQ_FOREACH(td, &ts->ts_blocked[TS_EXCLUSIVE_QUEUE], td_lockq) + print_waiter(td, indent + 1); + TAILQ_FOREACH(td, &ts->ts_blocked[TS_SHARED_QUEUE], td_lockq) + print_waiter(td, indent + 1); + TAILQ_FOREACH(td, &ts->ts_pending, td_lockq) + print_waiter(td, indent + 1); +} + +DB_SHOW_COMMAND(lockchain, db_show_lockchain) +{ + struct lock_object *lock; + struct lock_class *class; + struct turnstile_chain *tc; + struct turnstile *ts; + + if (!have_addr) + return; + lock = (struct lock_object *)addr; + tc = TC_LOOKUP(lock); + LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) + if (ts->ts_lockobj == lock) + break; + if (ts == NULL) { + class = LOCK_CLASS(lock); + db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, + lock->lo_name); + } else + print_waiters(ts, 0); +} #endif |
