Author: cem Date: Thu Aug 24 15:12:16 2017 New Revision: 322836 URL: https://svnweb.freebsd.org/changeset/base/322836
Log: Merge print_lockchain and print_sleepchain When debugging a deadlock, it is useful to follow the full chain of locks as far as possible. Reviewed by: jhb Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D12115 Modified: head/sys/kern/subr_turnstile.c Modified: head/sys/kern/subr_turnstile.c ============================================================================== --- head/sys/kern/subr_turnstile.c Thu Aug 24 13:39:24 2017 (r322835) +++ head/sys/kern/subr_turnstile.c Thu Aug 24 15:12:16 2017 (r322836) @@ -1096,7 +1096,7 @@ found: /* * Show all the threads a particular thread is waiting on based on - * non-sleepable and non-spin locks. + * non-spin locks. */ static void print_lockchain(struct thread *td, const char *prefix) @@ -1104,10 +1104,11 @@ print_lockchain(struct thread *td, const char *prefix) struct lock_object *lock; struct lock_class *class; struct turnstile *ts; + struct thread *owner; /* * Follow the chain. We keep walking as long as the thread is - * blocked on a turnstile that has an owner. + * blocked on a lock that has an owner. */ while (!db_pager_quit) { db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, @@ -1136,6 +1137,17 @@ print_lockchain(struct thread *td, const char *prefix) return; td = ts->ts_owner; break; + } else if (TD_ON_SLEEPQ(td)) { + if (!lockmgr_chain(td, &owner) && + !sx_chain(td, &owner)) { + db_printf("sleeping on %p \"%s\"\n", + td->td_wchan, td->td_wmesg); + return; + } + if (owner == NULL) + return; + td = owner; + break; } db_printf("inhibited\n"); return; @@ -1158,6 +1170,7 @@ DB_SHOW_COMMAND(lockchain, db_show_lockchain) print_lockchain(td, ""); } +DB_SHOW_ALIAS(sleepchain, db_show_lockchain); DB_SHOW_ALL_COMMAND(chains, db_show_allchains) { @@ -1168,84 +1181,17 @@ DB_SHOW_ALL_COMMAND(chains, db_show_allchains) i = 1; FOREACH_PROC_IN_SYSTEM(p) { FOREACH_THREAD_IN_PROC(p, td) { - if (TD_ON_LOCK(td) && LIST_EMPTY(&td->td_contested)) { + if ((TD_ON_LOCK(td) && LIST_EMPTY(&td->td_contested)) + || (TD_IS_INHIBITED(td) && TD_ON_SLEEPQ(td))) { db_printf("chain %d:\n", i++); print_lockchain(td, " "); } - if (TD_IS_INHIBITED(td) && TD_ON_SLEEPQ(td)) { - db_printf("chain %d:\n", i++); - print_sleepchain(td, " "); - } if (db_pager_quit) return; } } } DB_SHOW_ALIAS(allchains, db_show_allchains) - -/* - * Show all the threads a particular thread is waiting on based on - * sleepable locks. - */ -static void -print_sleepchain(struct thread *td, const char *prefix) -{ - struct thread *owner; - - /* - * Follow the chain. We keep walking as long as the thread is - * blocked on a sleep lock that has an owner. - */ - while (!db_pager_quit) { - db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, - td->td_proc->p_pid, td->td_name); - 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_SLEEPQ(td)) { - if (lockmgr_chain(td, &owner) || - sx_chain(td, &owner)) { - if (owner == NULL) - return; - td = owner; - break; - } - db_printf("sleeping on %p \"%s\"\n", - td->td_wchan, td->td_wmesg); - return; - } - db_printf("inhibited\n"); - return; - default: - db_printf("??? (%#x)\n", td->td_state); - return; - } - } -} - -DB_SHOW_COMMAND(sleepchain, db_show_sleepchain) -{ - struct thread *td; - - /* Figure out which thread to start with. */ - if (have_addr) - td = db_lookup_thread(addr, true); - else - td = kdb_thread; - - print_sleepchain(td, ""); -} static void print_waiters(struct turnstile *ts, int indent); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
