RE: [PATCH v2] storvsc: Set up correct queue depth values for IDE devices

[Long Li]

Hi Martin

Can you take a look at the following patch?

Long

 
> > -----Original Message-----
> > From: linux-kernel-owner@xxxxxxxxxxxxxxx
> > <linux-kernel-owner@xxxxxxxxxxxxxxx> On Behalf Of Long Li
> > Sent: Thursday, March 22, 2018 2:47 PM
> > To: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang
> > <haiyangz@xxxxxxxxxxxxx>; Stephen Hemminger
> <sthemmin@xxxxxxxxxxxxx>;
> > James E . J . Bottomley <JBottomley@xxxxxxxx>; Martin K . Petersen
> > <martin.petersen@xxxxxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxxxx; linux-
> > scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Cc: Long Li <longli@xxxxxxxxxxxxx>
> > Subject: [PATCH v2] storvsc: Set up correct queue depth values for IDE
> > devices
> >
> > From: Long Li <longli@xxxxxxxxxxxxx>
> >
> > Unlike SCSI and FC, we don't use multiple channels for IDE.
> > Also fix the calculation for sub-channels.
> >
> > Change log:
> > v2: Addressed comment on incorrect number of sub-channels.
> > (Michael Kelley <Michael.H.Kelley@xxxxxxxxxxxxx>)
> >
> > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> 
> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> 
> > ---
> >  drivers/scsi/storvsc_drv.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> > index 8c51d628b52e..a2ec0bc9e9fa 100644
> > --- a/drivers/scsi/storvsc_drv.c
> > +++ b/drivers/scsi/storvsc_drv.c
> > @@ -1722,11 +1722,14 @@ static int storvsc_probe(struct hv_device
> *device,
> >  		max_targets = STORVSC_MAX_TARGETS;
> >  		max_channels = STORVSC_MAX_CHANNELS;
> >  		/*
> > -		 * On Windows8 and above, we support sub-channels for
> storage.
> > +		 * On Windows8 and above, we support sub-channels for
> storage
> > +		 * on SCSI and FC controllers.
> >  		 * The number of sub-channels offerred is based on the
> number of
> >  		 * VCPUs in the guest.
> >  		 */
> > -		max_sub_channels = (num_cpus /
> storvsc_vcpus_per_sub_channel);
> > +		if (!dev_is_ide)
> > +			max_sub_channels =
> > +				(num_cpus - 1) /
> storvsc_vcpus_per_sub_channel;
> >  	}
> >
> >  	scsi_driver.can_queue = (max_outstanding_req_per_channel *
> > --
> > 2.14.1