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authorDmitry Fomichev <dmitry.fomichev@wdc.com>2019-11-06 23:34:35 +0100
committerMike Snitzer <snitzer@redhat.com>2019-11-07 16:08:36 +0100
commite7fad909b68aa37470d9f2d2731b5bec355ee5d6 (patch)
tree46aa9d420dd63b0767cab11267db4a56b99435c0 /drivers/scsi/scsi_sysfs.c
parentdm dust: add limited write failure mode (diff)
downloadlinux-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/scsi_sysfs.c')
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