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| author | Adam Manzanares <adam.manzanares@hgst.com> | 2016-10-17 20:27:29 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2016-10-19 20:34:36 +0200 |
| commit | 8e061784b51ec4a4efed0deaafb5bd9725bf5b06 (patch) | |
| tree | 30d253d6d6a214f6514484bfe1d2c3b178fdf62e /drivers/ata/libata-scsi.c | |
| parent | block: Add iocontext priority to request (diff) | |
| download | linux-8e061784b51ec4a4efed0deaafb5bd9725bf5b06.tar.xz linux-8e061784b51ec4a4efed0deaafb5bd9725bf5b06.zip | |
ata: Enabling ATA Command Priorities
This patch checks to see if an ATA device supports NCQ command priorities.
If so and the user has specified an iocontext that indicates
IO_PRIO_CLASS_RT then we build a tf with a high priority command.
This is done to improve the tail latency of commands that are high
priority by passing priority to the device.
tj: Removed trivial ata_ncq_prio_enabled() and open-coded the test.
Signed-off-by: Adam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata/libata-scsi.c')
| -rw-r--r-- | drivers/ata/libata-scsi.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 9cceb4a875a5..2bccc3c7de48 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -50,6 +50,7 @@ #include <linux/uaccess.h> #include <linux/suspend.h> #include <asm/unaligned.h> +#include <linux/ioprio.h> #include "libata.h" #include "libata-transport.h" @@ -1755,6 +1756,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc) { struct scsi_cmnd *scmd = qc->scsicmd; const u8 *cdb = scmd->cmnd; + struct request *rq = scmd->request; + int class = IOPRIO_PRIO_CLASS(req_get_ioprio(rq)); unsigned int tf_flags = 0; u64 block; u32 n_block; @@ -1821,7 +1824,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc) qc->nbytes = n_block * scmd->device->sector_size; rc = ata_build_rw_tf(&qc->tf, qc->dev, block, n_block, tf_flags, - qc->tag); + qc->tag, class); + if (likely(rc == 0)) return 0; |