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| author | Ming Lei <ming.lei@redhat.com> | 2020-09-10 15:50:56 +0800 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-09-15 22:20:11 -0400 |
| commit | ed5dd6a67d5eac5fb8873697b55dc1699752a9f3 (patch) | |
| tree | f2b12578e83f2b256c0dbf532741ee1f41d110d3 /include/scsi | |
| parent | f97e6e1eabbfed0ec3ccce7562df26a5b21d0d99 (diff) | |
| download | linux-ed5dd6a67d5eac5fb8873697b55dc1699752a9f3.tar.gz linux-ed5dd6a67d5eac5fb8873697b55dc1699752a9f3.tar.bz2 linux-ed5dd6a67d5eac5fb8873697b55dc1699752a9f3.zip | |
scsi: core: Only re-run queue in scsi_end_request() if device queue is busy
The request queue is currently run unconditionally in scsi_end_request() if
both target queue and host queue are ready.
Recently Long Li reported that cost of a queue run can be very heavy in
case of high queue depth. Improve this situation by only running the
request queue when this LUN is busy.
Link: https://lore.kernel.org/r/20200910075056.36509-1-ming.lei@redhat.com
Reported-by: Long Li <longli@microsoft.com>
Tested-by: Long Li <longli@microsoft.com>
Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/scsi')
| -rw-r--r-- | include/scsi/scsi_device.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index bc5909033d13..1a5c9a3df6d6 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -109,6 +109,7 @@ struct scsi_device { atomic_t device_busy; /* commands actually active on LLDD */ atomic_t device_blocked; /* Device returned QUEUE_FULL. */ + atomic_t restarts; spinlock_t list_lock; struct list_head starved_entry; unsigned short queue_depth; /* How deep of a queue we want */ |