What is wrong with FreeBSD and USB Support

Markus Rechberger mrechberger at gmail.com
Mon Mar 6 11:42:52 UTC 2017

On Mon, Mar 6, 2017 at 12:40 PM, Hans Petter Selasky <hps at selasky.org> wrote:
> Hi,
> On 03/06/17 12:36, Markus Rechberger wrote:
>> libusb20 - usb userspace interface - usb - roundtrip problem that
>> causes this high latency.
> If you are using an old FreeBSD kernel, more than two years old, there was
> an issue where malloc() was used in the generic IOCTL path. This piece has
> in later versions of FreeBSD been replace with a conditional on-stack
> buffer. If you have this issue you should see high CPU usage on one of the
> CPU cores while doing USB transfers fast.

I'm using FreeBSD 11 the latest one.

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