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author | Dmitry Fomichev <dmitry.fomichev@wdc.com> | 2019-11-06 23:34:35 +0100 |
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committer | Mike Snitzer <snitzer@redhat.com> | 2019-11-07 16:08:36 +0100 |
commit | e7fad909b68aa37470d9f2d2731b5bec355ee5d6 (patch) | |
tree | 46aa9d420dd63b0767cab11267db4a56b99435c0 /drivers/scsi/ibmvscsi_tgt/libsrp.h | |
parent | dm dust: add limited write failure mode (diff) | |
download | linux-e7fad909b68aa37470d9f2d2731b5bec355ee5d6.tar.xz linux-e7fad909b68aa37470d9f2d2731b5bec355ee5d6.zip |
dm zoned: reduce overhead of backing device checks
Commit 75d66ffb48efb3 added backing device health checks and as a part
of these checks, check_events() block ops template call is invoked in
dm-zoned mapping path as well as in reclaim and flush path. Calling
check_events() with ATA or SCSI backing devices introduces a blocking
scsi_test_unit_ready() call being made in sd_check_events(). Even though
the overhead of calling scsi_test_unit_ready() is small for ATA zoned
devices, it is much larger for SCSI and it affects performance in a very
negative way.
Fix this performance regression by executing check_events() only in case
of any I/O errors. The function dmz_bdev_is_dying() is modified to call
only blk_queue_dying(), while calls to check_events() are made in a new
helper function, dmz_check_bdev().
Reported-by: zhangxiaoxu <zhangxiaoxu5@huawei.com>
Fixes: 75d66ffb48efb3 ("dm zoned: properly handle backing device failure")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/scsi/ibmvscsi_tgt/libsrp.h')
0 files changed, 0 insertions, 0 deletions