RE: [Xen-devel] [PATCH resend] xen-netback: switch to threaded irq for control ring

-----Original Message-----
From: Juergen Gross [mailto:jgross@suse.com]
Sent: 22 September 2016 11:39
To: Paul Durrant <redacted>; xen-devel@lists.xenproject.org;
netdev@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: Wei Liu <redacted>
Subject: Re: [Xen-devel] [PATCH resend] xen-netback: switch to threaded irq
for control ring

On 22/09/16 12:31, Paul Durrant wrote:

quoted

quoted

-----Original Message-----
From: Juergen Gross [mailto:jgross@suse.com]
Sent: 22 September 2016 11:17
To: Paul Durrant <redacted>;
xen-devel@lists.xenproject.org; netdev@vger.kernel.orga
[off-list ref]; linux- kernel@vger.kernel.org
Cc: Wei Liu <redacted>
Subject: Re: [Xen-devel] [PATCH resend] xen-netback: switch to
threaded irq for control ring

On 22/09/16 11:09, Paul Durrant wrote:

quoted

quoted

-----Original Message-----
From: Xen-devel [mailto:xen-devel-bounces@lists.xen.org] On Behalf
Of Juergen Gross
Sent: 22 September 2016 10:03
To: xen-devel@lists.xenproject.org; netdev@vger.kernel.orga; linux-
kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>; Wei Liu <redacted>
Subject: [Xen-devel] [PATCH resend] xen-netback: switch to threaded
irq for control ring

Instead of open coding it use the threaded irq mechanism in xen-

netback.

quoted

quoted

quoted

quoted

Signed-off-by: Juergen Gross <jgross@suse.com>

How have you tested this change?

Only compile-tested and loaded the module. As this feature isn't
being used in linux netfront AFAIK it is not easily testable. OTOH
the code modification is rather limited and I've used the threaded
irq in the Xen scsiback driver myself, so I'm rather confident it will work.

OK. How about doing the rx interrupt/task too so that it can be easily

tested with a linux netfront?

I'd like to, but this would require some more work. The rx kthread isn't
activated by an event only, but by a timer, too. This isn't easy to map to the
threaded irq framework. If, however, you are confident the timer isn't really
necessary I'd be happy to provide a patch switching the rx task to the
threaded irq, too.

And to be honest: this wouldn't verify that the control ring related patch is
really working. The mechanism itself _is_ working as it is already in use in
xen-scsiback in a very similar environment.

Ok. If you have confidence then...

Reviewed-by: Paul Durrant <redacted>

Juergen