>Subject: RE: [Patch v3] storvsc: setup 1:1 mapping between hardware queue >and CPU queue > >From: Long Li <longli@xxxxxxxxxxxxx> Sent: Thursday, September 5, 2019 3:55 >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_present_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>) >> v3: use num_present_cpus() instead of num_online_cpus(). Hyper-v >> doesn't support hot-add CPUs. (suggested by Michael Kelley >> <mikelley@xxxxxxxxxxxxx>) > >I've mostly seen the "Changes:" section placed below the "---" so that it >doesn't clutter up the commit log. But maybe there's not a strong >requirement one way or the other as I didn't find anything called out in the >"Documentation/process" >directory. Should I resubmit the patch (but keep it v3)? > >Michael > >> >> 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..cf987712041a 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_present_cpus(); >> >> /* >> * Set the error handler work queue. >> -- >> 2.17.1
