mirror_zfs/include
Prakash Surya 92334b14ec Add new kstat for monitoring time in dmu_tx_assign
This change adds a new kstat to gain some visibility into the amount of
time spent in each call to dmu_tx_assign. A histogram is exported via
a new dmu_tx_assign_histogram-$POOLNAME file. The information contained
in this histogram is the frequency dmu_tx_assign took to complete given
an interval range. For example, given the below histogram file:

    $ cat /proc/spl/kstat/zfs/dmu_tx_assign_histogram-tank
    12 1 0x01 32 1536 19792068076691 20516481514522
    name                            type data
    1 us                            4    859
    2 us                            4    252
    4 us                            4    171
    8 us                            4    2
    16 us                           4    0
    32 us                           4    2
    64 us                           4    0
    128 us                          4    0
    256 us                          4    0
    512 us                          4    0
    1024 us                         4    0
    2048 us                         4    0
    4096 us                         4    0
    8192 us                         4    0
    16384 us                        4    0
    32768 us                        4    1
    65536 us                        4    1
    131072 us                       4    1
    262144 us                       4    4
    524288 us                       4    0
    1048576 us                      4    0
    2097152 us                      4    0
    4194304 us                      4    0
    8388608 us                      4    0
    16777216 us                     4    0
    33554432 us                     4    0
    67108864 us                     4    0
    134217728 us                    4    0
    268435456 us                    4    0
    536870912 us                    4    0
    1073741824 us                   4    0
    2147483648 us                   4    0

one can see most calls to dmu_tx_assign completed in 32us or less, but a
few outliers did not. Specifically, 4 of the calls took between 262144us
and 131072us. This information is difficult, if not impossible, to gather
without this change.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1584
2013-07-11 13:53:44 -07:00
..
linux Add SEEK_DATA/SEEK_HOLE to lseek()/llseek() 2013-07-02 09:24:43 -07:00
sys Add new kstat for monitoring time in dmu_tx_assign 2013-07-11 13:53:44 -07:00
libnvpair.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil_common.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libuutil.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
libzfs_impl.h Illumos #1644, #1645, #1646, #1647, #1708 2012-07-31 09:25:30 -07:00
libzfs.h Add FreeBSD 'zpool labelclear' command 2013-07-09 15:58:05 -07:00
Makefile.am Change zfs-kmod-devel install path 2013-03-13 13:42:16 -07:00
zfeature_common.h Illumos #3035 LZ4 compression support in ZFS and GRUB 2013-01-29 09:28:20 -08:00
zfs_comutil.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_deleg.h Illumos #278: get rid zfs of python and pyzfs dependencies 2011-08-01 12:09:36 -07:00
zfs_fletcher.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_namecheck.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_prop.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zpios-ctl.h Refresh links to web site 2013-03-06 15:46:41 -08:00
zpios-internal.h Refresh links to web site 2013-03-06 15:46:41 -08:00