Messages in this thread | | | From | John Garry <> | Subject | [PATCH 0/2] scsi/libata: A potential tagging fix and improvement | Date | Tue, 15 Mar 2022 18:39:04 +0800 |
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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(-)
-- 2.26.2
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