freebsd-nq/module
Brian Behlendorf 0b1401ee91 Add visibility in to txg sync behavior
This change is an attempt to add visibility in to how txgs are being
formed on a system, in real time. To do this, a list was added to the
in memory SPA data structure for a pool, with each element on the list
corresponding to txg. These entries are then exported through the kstat
interface, which can then be interpreted in userspace.

For each txg, the following information is exported:

 * Unique txg number (uint64_t)
 * The time the txd was born (hrtime_t)
   (*not* wall clock time; relative to the other entries on the list)
 * The current txg state ((O)pen/(Q)uiescing/(S)yncing/(C)ommitted)
 * The number of reserved bytes for the txg (uint64_t)
 * The number of bytes read during the txg (uint64_t)
 * The number of bytes written during the txg (uint64_t)
 * The number of read operations during the txg (uint64_t)
 * The number of write operations during the txg (uint64_t)
 * The time the txg was closed (hrtime_t)
 * The time the txg was quiesced (hrtime_t)
 * The time the txg was synced (hrtime_t)

Note that while the raw kstat now stores relative hrtimes for the
open, quiesce, and sync times.  Those relative times are used to
calculate how long each state took and these deltas and printed by
output handlers.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-10-25 13:57:25 -07:00
..
avl Add script for builtin module building. 2012-07-26 13:45:09 -07:00
nvpair Illumos #3464 2013-09-04 16:01:24 -07:00
unicode Add script for builtin module building. 2012-07-26 13:45:09 -07:00
zcommon Illumos #2882, #2883, #2900 2013-09-04 15:49:00 -07:00
zfs Add visibility in to txg sync behavior 2013-10-25 13:57:25 -07:00
zpios Illumos #3464 2013-09-04 16:01:24 -07:00
.gitignore gitignore: anchor entries at their respective directory 2013-04-02 10:50:17 -07:00
Makefile.in Add KMODDIR to install target 2013-03-06 15:46:40 -08:00