Re: [PATCH for-next V2 0/9] Add completion timestamping support

[Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

[-- Attachment #1: Type: text/plain, Size: 996 bytes --]

On Thu, 2015-06-04 at 16:17 +0000, Hefty, Sean wrote:
> > No, if they followed (I didn't check yes) the extension scheme then the
> > poll call is
> > 
> >  struct ibv_wc_ex wcs[num_wcs]
> >  ibv_poll_wc_ex(&wcs,num_wcs,sizeof(wcs[0]));
> > 
> > And the drivers decide what to do based on the 3rd argument, which is
> > essentially the ABI version.
> 
> As a couple of options:
> 
> You could add a 'completion format' field to the cq attribute structure, which would allow poll to cast to a specific structure.

This is probably what I would consider an ideal way to handle things.

> If we wanted to go with Doug's earlier idea, you could add a 'provider context' field to the wc.  This would allow calling back into the provider to retrieve more data.  Though, this concept would be racy if other completions can overwrite whatever data was trying to be retrieved.


-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
              GPG KeyID: 0E572FDD


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 819 bytes --]