dm rq: Avoid that request processing stalls sporadically
authorBart Van Assche <bart.vanassche@sandisk.com>
Fri, 7 Apr 2017 18:16:54 +0000 (11:16 -0700)
committerJens Axboe <axboe@fb.com>
Fri, 7 Apr 2017 18:27:10 +0000 (12:27 -0600)
commit6077c2d706097c00d8f2fed57d3f3c45cd228ee8
tree5acae1a06b2b108a20a84697422159321843c2ba
parent36e3cf273977da34a760d513e1bef8431a9abaa0
dm rq: Avoid that request processing stalls sporadically

While running the srp-test software I noticed that request
processing stalls sporadically at the beginning of a test, namely
when mkfs is run against a dm-mpath device. Every time when that
happened the following command was sufficient to resume request
processing:

    echo run >/sys/kernel/debug/block/dm-0/state

This patch avoids that such request processing stalls occur. The
test I ran is as follows:

    while srp-test/run_tests -d -r 30 -t 02-mq; do :; done

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/md/dm-rq.c