RE: [PATCH v3 3/4] xen/interface: re-define FRONT/BACK_RING_ATTACH()

From: Durrant, Paul
Date: Fri Dec 13 2019 - 04:02:49 EST


> -----Original Message-----
> From: JÃrgen Groà <jgross@xxxxxxxx>
> Sent: 13 December 2019 09:00
> To: Durrant, Paul <pdurrant@xxxxxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx;
> linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>; Stefano Stabellini
> <sstabellini@xxxxxxxxxx>
> Subject: Re: [PATCH v3 3/4] xen/interface: re-define
> FRONT/BACK_RING_ATTACH()
>
> On 12.12.19 07:04, JÃrgen Groà wrote:
> > On 11.12.19 16:29, Paul Durrant wrote:
> >> Currently these macros are defined to re-initialize a front/back ring
> >> (respectively) to values read from the shared ring in such a way that
> any
> >> requests/responses that are added to the shared ring whilst the
> >> front/back
> >> is detached will be skipped over. This, in general, is not a desirable
> >> semantic since most frontend implementations will eventually block
> >> waiting
> >> for a response which would either never appear or never be processed.
> >>
> >> Since the macros are currently unused, take this opportunity to re-
> define
> >> them to re-initialize a front/back ring using specified values. This
> also
> >> allows FRONT/BACK_RING_INIT() to be re-defined in terms of
> >> FRONT/BACK_RING_ATTACH() using a specified value of 0.
> >>
> >> NOTE: BACK_RING_ATTACH() will be used directly in a subsequent patch.
> >>
> >> Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
> >
> > Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
>
> Paul, I think you should send a patch changing ring.h in the Xen tree.
>
> As soon as it has been accepted I'll take your series for the kernel.
>

Ok. I was waiting for a push so that I could cite the commit hash but I'll prep something now instead.

Paul