Messages in this thread Patch in this message | | | From | Long Li <> | Subject | [PATCH 1/3] storvsc: use tagged SRB requests if supported by the device | Date | Tue, 6 Sep 2016 14:25:41 -0700 |
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From: Long Li <longli@microsoft.com>
Properly set SRB flags when hosting device supports tagged queuing. This patch improves the performance on Fiber Channel disks.
--- drivers/scsi/storvsc_drv.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 8ccfc9e..a8f3e4c 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -136,6 +136,8 @@ struct hv_fc_wwn_packet { #define SRB_FLAGS_PORT_DRIVER_RESERVED 0x0F000000 #define SRB_FLAGS_CLASS_DRIVER_RESERVED 0xF0000000 +#define SP_UNTAGGED ((unsigned char) ~0) +#define SRB_SIMPLE_TAG_REQUEST 0x20 /* * Platform neutral description of a scsi request - @@ -1451,6 +1453,12 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd) vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DISABLE_SYNCH_TRANSFER; + if(scmnd->device->tagged_supported) { + vm_srb->win8_extension.srb_flags |= (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE); + vm_srb->win8_extension.queue_tag = SP_UNTAGGED; + vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST; + } + /* Build the SRB */ switch (scmnd->sc_data_direction) { case DMA_TO_DEVICE: -- 1.8.5.6
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