Re: [PATCH for-next 09/10] IB/mlx4: Add timestamp_mask and hca_core_clock to query_device

Christoph Lameter
2015-05-29T13:46:06Z

On Thu, 28 May 2015, Jason Gunthorpe wrote:

> My point was exposing raw wrapping counters is a horrible UAPI.

Well this is a kernel bypass API and a lot of raw hardware issues will
have to be handled since you do go directly to the device.

> > through a complete cycle. But that is the nature of these counters. And
> > thats what you see when you look into the kernel timer subsystem for
> > example.
>
> Very little in the kernel is exposed to that wrapping, the timer
> subsystem takes care of it. Certainly, userspace never sees it.

Right but then we are not at the comfortable sockets API here but at the
bare metal level.