On 3/15/22 19:39, John Garry wrote: > Two loosely related patches are included: > > - Fix for scsi_realloc_sdev_budget_map(). I noticed that the budget token > for scsi commands was way in excess of the device queue depth, so I > think we need to fix the sbitmap depth. I need to test this more. > > - libata change to use scsi command budget token for qc tag for SAS host. > I marked this as RFC as for SAS hosts I don't see anything which > guarantees that the budget size is <= 32 always. > For libsas hosts we resize the device depth to 32 in the slave configure > callback, but this seems an unreliable approach since not all hosts may > call this. > In addition, I am worried that even if we resize the device depth > properly in the slave config callback, we may still try to alloc qc tag > prior to this - in lun scan, for example. > So we need a way to guarantee that the device queue depth is <= 32 > always, which I would be open to suggestions for. > > John Garry (2): > scsi: core: Fix sbitmap depth in scsi_realloc_sdev_budget_map() > libata: Use scsi cmnd budget token for qc tag for SAS host > > drivers/ata/libata-core.c | 5 +++-- > drivers/ata/libata-sata.c | 21 ++++----------------- > drivers/ata/libata-scsi.c | 2 +- > drivers/ata/libata.h | 4 ++-- > drivers/scsi/scsi_scan.c | 5 +++++ > include/linux/libata.h | 1 - > 6 files changed, 15 insertions(+), 23 deletions(-) > I tested this and it is working fine for me. This actually solves the QD not changing problem I had detected with the pm80xx driver. Now, doing this: # cat /sys/block/sde/device/queue_depth 32 # echo 16 > /sys/block/sde/device/queue_depth # cat /sys/block/sde/device/queue_depth 16 is working as expected. See my comments on patch 2 for getting final ack and tested tags :) -- Damien Le Moal Western Digital Research
