mirror_zfs/module
Alexander Motin 701ebd014a OpenZFS 8835 - Speculative prefetch in ZFS not working for misaligned reads
In case of misaligned I/O sequential requests are not detected as such
due to overlaps in logical block sequence:

    dmu_zfetch(fffff80198dd0ae0, 27347, 9, 1)
    dmu_zfetch(fffff80198dd0ae0, 27355, 9, 1)
    dmu_zfetch(fffff80198dd0ae0, 27363, 9, 1)
    dmu_zfetch(fffff80198dd0ae0, 27371, 9, 1)
    dmu_zfetch(fffff80198dd0ae0, 27379, 9, 1)
    dmu_zfetch(fffff80198dd0ae0, 27387, 9, 1)

This patch makes single block overlap to be counted as a stream hit,
improving performance up to several times.

Authored by: Alexander Motin <mav@FreeBSD.org>
Approved by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Allan Jude <allanjude@freebsd.org>
Reviewed by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed by: George Melikov <mail@gmelikov.ru>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/8835
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/aab6dd482a
Closes #7062
2018-01-30 10:27:31 -06:00
..
avl Fix uninitialized variable in avl_add() 2016-07-25 14:21:34 -07:00
icp Linux 4.14 compat: CONFIG_GCC_PLUGIN_RANDSTRUCT 2017-12-04 17:21:39 -08:00
nvpair Linux 4.14 compat: CONFIG_GCC_PLUGIN_RANDSTRUCT 2017-12-04 17:21:39 -08:00
unicode codebase style improvements for OpenZFS 6459 port 2017-01-22 13:25:40 -08:00
zcommon Fix buffer overflow in dsl_dataset_name() 2017-07-24 12:56:49 -07:00
zfs OpenZFS 8835 - Speculative prefetch in ZFS not working for misaligned reads 2018-01-30 10:27:31 -06:00
zpios codebase style improvements for OpenZFS 6459 port 2017-01-22 13:25:40 -08:00
.gitignore Improve gitignore 2017-05-25 10:14:13 -07:00
Makefile.in GZIP compression offloading with QAT accelerator 2017-03-22 17:58:47 -07:00