From: Long Li <longli@xxxxxxxxxxxxxxxxx> Sent: Thursday, August 22, 2019 1:42 PM > > storvsc doesn't use a dedicated hardware queue for a given CPU queue. When > issuing I/O, it selects returning CPU (hardware queue) dynamically based on > vmbus channel usage across all channels. > > This patch advertises num_possible_cpus() as number of hardware queues. This > will have upper layer setup 1:1 mapping between hardware queue and CPU queue > and avoid unnecessary locking when issuing I/O. > > Changes: > v2: rely on default upper layer function to map queues. (suggested by Ming Lei > <tom.leiming@xxxxxxxxx>) > > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx> > --- > drivers/scsi/storvsc_drv.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index b89269120a2d..dfd3b76a4f89 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -1836,8 +1836,7 @@ static int storvsc_probe(struct hv_device *device, > /* > * Set the number of HW queues we are supporting. > */ > - if (stor_device->num_sc != 0) > - host->nr_hw_queues = stor_device->num_sc + 1; > + host->nr_hw_queues = num_possible_cpus(); For a lot of the VM sizes in Azure, num_possible_cpus() is 128, even if the VM has only 4 or 8 or some other smaller number of vCPUs. So I'm wondering if you really want num_present_cpus() here instead, which would include only the vCPUs that actually exist in the VM. Michael > > /* > * Set the error handler work queue. > -- > 2.17.1
