mirror_zfs/module
Brian Behlendorf 3b36f8319d Add dbgmsg kstat
Internally ZFS keeps a small log to facilitate debugging.  By default
the log is disabled, to enable it set zfs_dbgmsg_enable=1.  The contents
of the log can be accessed by reading the /proc/spl/kstat/zfs/dbgmsg file.
Writing 0 to this proc file clears the log.

$ echo 1 >/sys/module/zfs/parameters/zfs_dbgmsg_enable
$ echo 0 >/proc/spl/kstat/zfs/dbgmsg
$ zpool import tank
$ cat /proc/spl/kstat/zfs/dbgmsg
1 0 0x01 -1 0 2492357525542 2525836565501
timestamp    message
1441141408   spa=tank async request task=1
1441141408   txg 70 open pool version 5000; software version 5000/5; ...
1441141409   spa=tank async request task=32
1441141409   txg 72 import pool version 5000; software version 5000/5; ...
1441141414   command: lt-zpool import tank

Note the zfs_dbgmsg() and dprintf() functions are both now mapped to
the same log.  As mentioned above the kernel debug log can be accessed
though the /proc/spl/kstat/zfs/dbgmsg kstat.  For user space consumers
log messages are immediately written to stdout after applying the
ZFS_DEBUG environment variable.

$ ZFS_DEBUG=on ./cmd/ztest/ztest -V

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #3728
2015-09-04 16:08:14 -07:00
..
avl Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
nvpair Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
unicode Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
zcommon Linux 4.1 compat: loop device on ZFS 2015-08-24 10:17:06 -07:00
zfs Add dbgmsg kstat 2015-09-04 16:08:14 -07:00
zpios Linux 4.2 compat: misc_deregister() 2015-09-01 09:33:18 -07:00
.gitignore gitignore: anchor entries at their respective directory 2013-04-02 10:50:17 -07:00
Makefile.in Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00