Archive-Team
/
zfs
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 103 Wiki Activity
zfs/include/sys
History
Etienne Dechamps 34037afe24 Improve ZVOL queue behavior. 
The Linux block device queue subsystem exposes a number of configurable
settings described in Linux block/blk-settings.c. The defaults for these
settings are tuned for hard drives, and are not optimized for ZVOLs. Proper
configuration of these options would allow upper layers (I/O scheduler) to
take better decisions about write merging and ordering.

Detailed rationale:

 - max_hw_sectors is set to unlimited (UINT_MAX). zvol_write() is able to
   handle writes of any size, so there's no reason to impose a limit. Let the
   upper layer decide.

 - max_segments and max_segment_size are set to unlimited. zvol_write() will
   copy the requests' contents into a dbuf anyway, so the number and size of
   the segments are irrelevant. Let the upper layer decide.

 - physical_block_size and io_opt are set to the ZVOL's block size. This
   has the potential to somewhat alleviate issue #361 for ZVOLs, by warning
   the upper layers that writes smaller than the volume's block size will be
   slow.

 - The NONROT flag is set to indicate this isn't a rotational device.
   Although the backing zpool might be composed of rotational devices, the
   resulting ZVOL often doesn't exhibit the same behavior due to the COW
   mechanisms used by ZFS. Setting this flag will prevent upper layers from
   making useless decisions (such as reordering writes) based on incorrect
   assumptions about the behavior of the ZVOL.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
 		2012-02-07 16:23:06 -08:00
..
fm Improve ZVOL queue behavior. 2012-02-07 16:23:06 -08:00
fs Improve ZVOL queue behavior. 2012-02-07 16:23:06 -08:00
Makefile.am Add the release component to headers 2012-01-18 12:19:47 -08:00
Makefile.in Improve ZVOL queue behavior. 2012-02-07 16:23:06 -08:00
arc.h Linux 3.1 compat, super_block->s_shrink 2012-01-11 11:46:02 -08:00
avl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
avl_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
bplist.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
bpobj.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dbuf.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
ddt.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dmu.h Illumos #755: dmu_recv_stream builds incomplete guid_to_ds_map 2011-10-18 11:18:14 -07:00
dmu_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dmu_objset.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dmu_traverse.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dmu_tx.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dmu_zfetch.h Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
dnode.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_dataset.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_deadlist.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_deleg.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_dir.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_pool.h Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
dsl_prop.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_scan.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
dsl_synctask.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
efi_partition.h Make libefi-created GPT compatible with gptfdisk 2011-09-26 09:44:43 -07:00
metaslab.h Illumos #1051: zfs should handle imbalanced luns 2011-08-01 12:09:11 -07:00
metaslab_impl.h Illumos #1051: zfs should handle imbalanced luns 2011-08-01 12:09:11 -07:00
nvpair.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
nvpair_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
refcount.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
rrwlock.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
sa.h Implement SA based xattrs 2011-11-28 15:45:51 -08:00
sa_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
spa.h Illumos #1051: zfs should handle imbalanced luns 2011-08-01 12:09:11 -07:00
spa_boot.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
spa_impl.h Illumos #1051: zfs should handle imbalanced luns 2011-08-01 12:09:11 -07:00
space_map.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
txg.h Add API to wait for pending commit callbacks 2011-02-16 11:20:06 -08:00
txg_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
u8_textprep.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
u8_textprep_data.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uberblock.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uberblock_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uio_impl.h Add basic uio support 2011-02-10 09:21:43 -08:00
unique.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uuid.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
vdev.h Add missing ZFS tunables 2011-05-04 10:02:37 -07:00
vdev_disk.h Linux 2.6.x compat, blkdev_compat.h 2011-02-23 12:29:38 -08:00
vdev_file.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
vdev_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
xvattr.h Add xvattr support 2011-03-02 11:43:50 -08:00
zap.h Export symbols for the full ZAP API 2011-09-27 16:12:36 -07:00
zap_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zap_leaf.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_acl.h Add xvattr support 2011-03-02 11:43:50 -08:00
zfs_context.h Cleanup ZFS debug infrastructure 2012-02-02 11:24:30 -08:00
zfs_debug.h Cleanup ZFS debug infrastructure 2012-02-02 11:24:30 -08:00
zfs_dir.h Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
zfs_fuid.h Prototype/structure update for Linux 2011-02-10 09:27:21 -08:00
zfs_ioctl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_onexit.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_rlock.h Range lock performance improvements 2011-03-08 12:44:06 -08:00
zfs_sa.h Implement SA based xattrs 2011-11-28 15:45:51 -08:00
zfs_stat.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_vfsops.h Increase link count limit to 2^31-1 2012-01-13 11:43:59 -08:00
zfs_vnops.h Cleanup mmap(2) writes 2011-08-02 10:34:55 -07:00
zfs_znode.h Implement SA based xattrs 2011-11-28 15:45:51 -08:00
zil.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zil_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zio.h Illumos #734: Use taskq_dispatch_ent() interface 2011-12-14 09:19:30 -08:00
zio_checksum.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zio_compress.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zio_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zpl.h Linux 3.1 compat, super_block->s_shrink 2012-01-11 11:46:02 -08:00
zrlock.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zvol.h Linux 2.6.x compat, blkdev_compat.h 2011-02-23 12:29:38 -08:00