On Tue, Jan 09, 2018 at 11:14:11AM -0800, Stephen Hemminger wrote: > On Tue, 9 Jan 2018 19:58:34 +0100 > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Tue, Jan 09, 2018 at 10:53:10AM -0800, Stephen Hemminger wrote: > > > On Tue, 9 Jan 2018 19:42:40 +0100 > > > Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > On Thu, Jan 04, 2018 at 02:13:29PM -0800, Stephen Hemminger wrote: > > > > > Allow setting size of ring buffer for host communication via > > > > > module parameter. > > > > > > > > > > Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> > > > > > --- > > > > > drivers/uio/uio_hv_generic.c | 25 +++++++++++++++++++++---- > > > > > 1 file changed, 21 insertions(+), 4 deletions(-) > > > > > > > > > > diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c > > > > > index 8d5f529a1dc1..24f8689fdb14 100644 > > > > > --- a/drivers/uio/uio_hv_generic.c > > > > > +++ b/drivers/uio/uio_hv_generic.c > > > > > @@ -39,6 +39,13 @@ > > > > > #define DRIVER_AUTHOR "Stephen Hemminger <sthemmin at microsoft.com>" > > > > > #define DRIVER_DESC "Generic UIO driver for VMBus devices" > > > > > > > > > > +#define RING_SIZE_MIN 64 > > > > > +#define RING_SIZE_MAX 512 > > > > > + > > > > > +static unsigned int ring_size = 128; > > > > > +module_param(ring_size, uint, 0444); > > > > > +MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)"); > > > > > > > > Ugh, really? Module parameters suck rocks. No other way to do this > > > > dynamically? This affects all devices for the driver, is that ok? > > > > > > > > And how does anyone know to change this or not? Why would it be > > > > changed? Why can't the kernel get this right on its own? > > > > > > You made UIO API so restrictive there is no parameterization available. > > > > _I_ did? Heck, I don't remember what I did last month, let alone almost > > a decade ago... > > > > > The size of ring buffer is generally unchanged. > > > > Then why is this needed at all? > > The default ring buffer is quite large, and wasteful with small VM's with network device driver > we do autotuning now based on number of channels which is based on number of cpu's. > > How about integrating that? Autotuning is great, I would love to see that. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
