diff options
| author |   visa <visa@openbsd.org> | 2021-01-28 15:13:27 +0000 |
|---|---|---|
| committer | visa <visa@openbsd.org> | 2021-01-28 15:13:27 +0000 |
| commit | b11d00d4979766d1079bdcd8187cadc440e81117 (patch) | |
| tree | f256133bfa32e6f254b1d2ccbf06bdc54ad3113b | |
| parent | Drop tcp_trace() from SMALL_KERNEL builds to make room on amd64 floppy (diff) | |
| download | wireguard-openbsd-b11d00d4979766d1079bdcd8187cadc440e81117.tar.xz wireguard-openbsd-b11d00d4979766d1079bdcd8187cadc440e81117.zip | |
Show when witness(4) has run out of lock order data entries.
This makes it clearer why lock order traces are sometimes not displayed.
Prompted by a question from, and OK anton@
| -rw-r--r-- | sys/kern/subr_witness.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c index 05a3079c377..9a4d3c28a84 100644 --- a/sys/kern/subr_witness.c +++ b/sys/kern/subr_witness.c @@ -1,4 +1,4 @@ -/* $OpenBSD: subr_witness.c,v 1.43 2021/01/09 20:59:06 gnezdo Exp $ */ +/* $OpenBSD: subr_witness.c,v 1.44 2021/01/28 15:13:27 visa Exp $ */ /*- * Copyright (c) 2008 Isilon Systems, Inc. @@ -1084,6 +1084,9 @@ witness_checkorder(struct lock_object *lock, int flags, w1->w_class->lc_name); stacktrace_print( &wlod1->wlod_stack, printf); + } else { + printf("lock order data " + "w2 -> w1 missing\n"); } if (wlod2 != NULL) { printf("lock order \"%s\"(%s) -> " @@ -1094,6 +1097,9 @@ witness_checkorder(struct lock_object *lock, int flags, w->w_class->lc_name); stacktrace_print( &wlod2->wlod_stack, printf); + } else { + printf("lock order data " + "w1 -> w2 missing\n"); } } witness_debugger(0); @@ -2436,6 +2442,7 @@ witness_lock_order_check(struct witness *parent, struct witness *child) static int witness_lock_order_add(struct witness *parent, struct witness *child) { + static int lofree_empty_reported = 0; struct witness_lock_order_data *data = NULL; struct witness_lock_order_key key; unsigned int hash; @@ -2453,8 +2460,13 @@ witness_lock_order_add(struct witness *parent, struct witness *child) sizeof(key)) % w_lohash.wloh_size; w_rmatrix[parent->w_index][child->w_index] |= WITNESS_LOCK_ORDER_KNOWN; data = w_lofree; - if (data == NULL) + if (data == NULL) { + if (!lofree_empty_reported) { + lofree_empty_reported = 1; + printf("witness: out of free lock order entries\n"); + } return (0); + } w_lofree = data->wlod_next; data->wlod_next = w_lohash.wloh_array[hash]; data->wlod_key = key; |