4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012 by Delphix. All rights reserved.
26 #include <sys/zfs_context.h>
30 kmutex_t zfs_dbgmsgs_lock;
31 int zfs_dbgmsg_maxsize = 1<<20; /* 1MB */
36 list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t),
37 offsetof(zfs_dbgmsg_t, zdm_node));
38 mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL);
46 while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) {
47 int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg);
49 zfs_dbgmsg_size -= size;
51 mutex_destroy(&zfs_dbgmsgs_lock);
52 ASSERT0(zfs_dbgmsg_size);
56 * Print these messages by running:
57 * echo ::zfs_dbgmsg | mdb -k
59 * Monitor these messages by running:
60 * dtrace -q -n 'zfs-dbgmsg{printf("%s\n", stringof(arg0))}'
63 zfs_dbgmsg(const char *fmt, ...)
70 size = vsnprintf(NULL, 0, fmt, adx);
74 * There is one byte of string in sizeof (zfs_dbgmsg_t), used
75 * for the terminating null.
77 zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP);
78 zdm->zdm_timestamp = gethrestime_sec();
81 (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx);
84 DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg);
86 mutex_enter(&zfs_dbgmsgs_lock);
87 list_insert_tail(&zfs_dbgmsgs, zdm);
88 zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size;
89 while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) {
90 zdm = list_remove_head(&zfs_dbgmsgs);
91 size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg);
93 zfs_dbgmsg_size -= size;
95 mutex_exit(&zfs_dbgmsgs_lock);