diff options
| author |  Dmitry Fomichev <dmitry.fomichev@wdc.com>
| 2019-11-06 14:34:35 -0800 |
|---|---|---|
| committer |  Mike Snitzer <snitzer@redhat.com>
| 2019-11-07 10:08:36 -0500 |
| commit | e7fad909b68aa37470d9f2d2731b5bec355ee5d6 (patch) | |
| tree | 46aa9d420dd63b0767cab11267db4a56b99435c0 /drivers/md/dm-zoned.h | |
| parent | dm dust: add limited write failure mode (diff) | |
| download | linux-e7fad909b68aa37470d9f2d2731b5bec355ee5d6.tar.gz linux-e7fad909b68aa37470d9f2d2731b5bec355ee5d6.tar.bz2 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/md/dm-zoned.h')
| -rw-r--r-- | drivers/md/dm-zoned.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h index d8e70b0ade35..5b5e493d479c 100644 --- a/drivers/md/dm-zoned.h +++ b/drivers/md/dm-zoned.h @@ -72,6 +72,7 @@ struct dmz_dev { /* Device flags. */ #define DMZ_BDEV_DYING (1 << 0) +#define DMZ_CHECK_BDEV (2 << 0) /* * Zone descriptor. @@ -255,5 +256,6 @@ void dmz_schedule_reclaim(struct dmz_reclaim *zrc); * Functions defined in dm-zoned-target.c */ bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev); +bool dmz_check_bdev(struct dmz_dev *dmz_dev); #endif /* DM_ZONED_H */ |