From c9337ad4390cdff8877e64824c2a2827d815743d Mon Sep 17 00:00:00 2001 From: John Garry Date: Tue, 19 Jul 2022 17:51:04 +0800 Subject: scsi: sd: Add a comment about limiting max_sectors to shost optimal limit 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 Signed-off-by: John Garry Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Signed-off-by: Christoph Hellwig --- drivers/scsi/sd.c | 5 +++++ 1 file changed, 5 insertions(+) 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 */ -- cgit v1.2.3