mirror_zfs/include
LOLi 77d8a0f1a4 Fix hung z_zvol tasks during 'zfs receive'
During a receive operation zvol_create_minors_impl() can wait
needlessly for the prefetch thread because both share the same tasks
queue.  This results in hung tasks:

<3>INFO: task z_zvol:5541 blocked for more than 120 seconds.
<3>      Tainted: P           O  3.16.0-4-amd64
<3>"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

The first z_zvol:5541 (zvol_task_cb) is waiting for the long running
traverse_prefetch_thread:260

root@linux:~# cat /proc/spl/taskq
taskq                       act  nthr  spwn  maxt   pri  mina
spl_system_taskq/0            1     2     0    64   100     1
	active: [260]traverse_prefetch_thread [zfs](0xffff88003347ae40)
	wait: 5541
spl_delay_taskq/0             0     1     0     4   100     1
	delay: spa_deadman [zfs](0xffff880039924000)
z_zvol/1                      1     1     0     1   120     1
	active: [5541]zvol_task_cb [zfs](0xffff88001fde6400)
	pend: zvol_task_cb [zfs](0xffff88001fde6800)

This change adds a dedicated, per-pool, prefetch taskq to prevent the
traverse code from monopolizing the global (and limited) system_taskq by
inappropriately scheduling long running tasks on it.

Reviewed-by: Albert Lee <trisk@forkgnu.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #6330 
Closes #6890 
Closes #7343
2018-03-30 12:10:01 -07:00
..
linux Linux 4.16 compat: get_disk_and_module() 2018-03-05 12:44:35 -08:00
sys Fix hung z_zvol tasks during 'zfs receive' 2018-03-30 12:10:01 -07:00
libnvpair.h Add JSON output support to channel programs 2018-03-19 12:40:58 -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 Correct cppcheck errors 2017-09-19 12:17:29 -07:00
libzfs_core.h OpenZFS 8677 - Open-Context Channel Programs 2018-02-08 16:05:57 -08:00
libzfs_impl.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
libzfs.h Report pool suspended due to MMP 2018-03-15 10:56:55 -07:00
Makefile.am Retire legacy test infrastructure 2017-08-15 17:26:38 -07:00
thread_pool.h Add libtpool (thread pools) 2017-08-09 15:31:08 -07:00
zfeature_common.h Project Quota on ZFS 2018-02-13 14:54:54 -08:00
zfs_comutil.h Illumos #2882, #2883, #2900 2013-09-04 15:49:00 -07:00
zfs_deleg.h Project Quota on ZFS 2018-02-13 14:54:54 -08:00
zfs_fletcher.h DLPX-44812 integrate EP-220 large memory scalability 2016-11-29 14:34:27 -08:00
zfs_namecheck.h OpenZFS 7386 - zfs get does not work properly with bookmarks 2017-01-26 14:42:15 -08:00
zfs_prop.h Native Encryption for ZFS on Linux 2017-08-14 10:36:48 -07:00