diff mbox series

scsi: sd: Add a comment about limiting max_sectors to shost optimal limit

Message ID 1658224264-49972-1-git-send-email-john.garry@huawei.com
State New
Headers show
Series scsi: sd: Add a comment about limiting max_sectors to shost optimal limit | expand

Commit Message

John Garry July 19, 2022, 9:51 a.m. UTC
Add a comment about limiting the default the SCSI disk request_queue
max_sectors initial value to that of the SCSI host optimal sectors limit.

Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: John Garry <john.garry@huawei.com>

Comments

Christoph Hellwig July 22, 2022, 3:15 p.m. UTC | #1
Thanks, applied.
diff mbox series

Patch

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3eaee1f7aaca..ed9f43f9512e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3296,6 +3296,11 @@  static int sd_revalidate_disk(struct gendisk *disk)
 				      (sector_t)BLK_DEF_MAX_SECTORS);
 	}
 
+	/*
+	 * Limit default to SCSI host optimal sector limit if set. There may be
+	 * an impact on performance for when the size of a request exceeds this
+	 * host limit.
+	 */
 	rw_max = min_not_zero(rw_max, sdp->host->opt_sectors);
 
 	/* Do not exceed controller limit */