On Wed, 2015-12-16 at 17:53 -0500, Martin K. Petersen wrote: > The OPTIMAL TRANSFER LENGTH reported by scsi_debug is 64 blocks which > translates to 32KB with the default logical block size. That's much > lower than what real storage devices typically report (256KB to 1MB). > > Bump the optimal transfer length to 1024 blocks. > > Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> > --- > drivers/scsi/scsi_debug.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c > index d09d60293c27..b80b037f2982 100644 > --- a/drivers/scsi/scsi_debug.c > +++ b/drivers/scsi/scsi_debug.c > @@ -129,7 +129,7 @@ static const char *scsi_debug_version_date = "20141022"; > #define DEF_NO_LUN_0 0 > #define DEF_NUM_PARTS 0 > #define DEF_OPTS 0 > -#define DEF_OPT_BLKS 64 > +#define DEF_OPT_BLKS 1024 > #define DEF_PHYSBLK_EXP 0 > #define DEF_PTYPE 0 > #define DEF_REMOVABLE false > @@ -4140,7 +4140,7 @@ MODULE_PARM_DESC(no_lun_0, "no LU number 0 (def=0 -> have lun 0)"); > MODULE_PARM_DESC(no_uld, "stop ULD (e.g. sd driver) attaching (def=0))"); > MODULE_PARM_DESC(num_parts, "number of partitions(def=0)"); > MODULE_PARM_DESC(num_tgts, "number of targets per host to simulate(def=1)"); > -MODULE_PARM_DESC(opt_blks, "optimal transfer length in block (def=64)"); > +MODULE_PARM_DESC(opt_blks, "optimal transfer length in blocks (def=1024)"); > MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)"); > MODULE_PARM_DESC(physblk_exp, "physical block exponent (def=0)"); > MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])"); Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
