diff options
| author | Ming Lei <ming.lei@redhat.com> | 2021-01-22 10:33:16 +0800 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-03-04 17:37:00 -0500 |
| commit | ca44532139514f5fb0a5a081cd8576e4abe54e65 (patch) | |
| tree | 7f0e8ab04af9f02ae8ca281fe501c2c9e8411839 /drivers/scsi/scsi.c | |
| parent | 8278807abd338f2246b6ae8057f2ec61a80a5614 (diff) | |
scsi: core: Make sure sdev->queue_depth is <= max(shost->can_queue, 1024)
Limit SCSI device's queue depth to max(host->can_queue, 1024) in
scsi_change_queue_depth(). 1024 is big enough for saturating current fast
SCSI LUN(SSD or RAID volume on multiple SSDs). Also single hardware queue
depth is usually enough for saturating single LUN because per-core
performance is often considered in storage design.
This patch is needed for replacing sdev->device_busy with sbitmap which has
to be pre-allocated with reasonable max depth.
Link: https://lore.kernel.org/r/20210122023317.687987-13-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/scsi.c')
| -rw-r--r-- | drivers/scsi/scsi.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 24619c3bebd5..a28d48c850cf 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -214,6 +214,15 @@ void scsi_finish_command(struct scsi_cmnd *cmd) scsi_io_completion(cmd, good_bytes); } + +/* + * 1024 is big enough for saturating the fast scsi LUN now + */ +static int scsi_device_max_queue_depth(struct scsi_device *sdev) +{ + return max_t(int, sdev->host->can_queue, 1024); +} + /** * scsi_change_queue_depth - change a device's queue depth * @sdev: SCSI Device in question @@ -223,6 +232,8 @@ void scsi_finish_command(struct scsi_cmnd *cmd) */ int scsi_change_queue_depth(struct scsi_device *sdev, int depth) { + depth = min_t(int, depth, scsi_device_max_queue_depth(sdev)); + if (depth > 0) { sdev->queue_depth = depth; wmb(); |