svn commit: r227541 - head/sys/dev/usb/controller

[mdf at FreeBSD.org]

On Tue, Nov 15, 2011 at 1:20 PM,  <mdf at freebsd.org> wrote:
> On Tue, Nov 15, 2011 at 1:02 PM, Hans Petter Selasky <hselasky at c2i.net> wrote:
>> For USB compliant operation, the USB stack requires hz to be greater or equal
>> to 250 hz, to put it like that. Mostly a requirement in USB gadget/device
>> mode.
>
> Really?  That's news to me.  Is that documented somewhere?  I know we
> still use hz=100 internally, but we're on stable/7 still so not using
> the new USB stack yet.

... and I also just remembered that I have seen recommendations that,
when FreeBSD is used as a virtual machine, hz should be set to 100 so
that the virtual interrupt overhead is reduced.  Those two
recommendations are at odds with each other.

Thanks,
matthew