Virtualization - Oct 2013 - [PATCH net V2 1/2] virtio-net: don't respond to cpu hotplug notifier if we're not ready

On Thu, Oct 17, 2013 at 09:57:41AM +1030, Rusty Russell
wrote:
> Jason Wang <jasowang at redhat.com> writes:
> > We're trying to re-configure the affinity unconditionally in cpu
hotplug
> > callback. This may lead the issue during resuming from s3/s4 since
> >
> > - virt queues haven't been allocated at that time.
> > - it's unnecessary since thaw method will re-configure the
affinity.
> >
> > Fix this issue by checking the config_enable and do nothing is
we're not ready.
> >
> > The bug were introduced by commit
8de4b2f3ae90c8fc0f17eeaab87d5a951b66ee17
> > (virtio-net: reset virtqueue affinity when doing cpu hotplug).
> >
> > Cc: Rusty Russell <rusty at rustcorp.com.au>
> > Cc: Michael S. Tsirkin <mst at redhat.com>
> > Cc: Wanlong Gao <gaowanlong at cn.fujitsu.com>
> > Acked-by: Michael S. Tsirkin <mst at redhat.com>
> > Reviewed-by: Wanlong Gao <gaowanlong at cn.fujitsu.com>
> > Signed-off-by: Jason Wang <jasowang at redhat.com>
> > ---
> > The patch is need for 3.8 and above.
> 
> Please put 'CC: stable at kernel.org # 3.8+' in the commit.
Not if this is going in through the net tree.
> 
> (The specification of the stable line is poor, but that seems to be one
> common method).
> 
> Cheers,
> Rusty.

"Michael S. Tsirkin" <mst at redhat.com>
writes:
> On Thu, Oct 17, 2013 at 09:57:41AM +1030, Rusty Russell wrote:
>> Jason Wang <jasowang at redhat.com> writes:
>> > We're trying to re-configure the affinity unconditionally in
cpu hotplug
>> > callback. This may lead the issue during resuming from s3/s4 since
>> >
>> > - virt queues haven't been allocated at that time.
>> > - it's unnecessary since thaw method will re-configure the
affinity.
>> >
>> > Fix this issue by checking the config_enable and do nothing is
we're not ready.
>> >
>> > The bug were introduced by commit
8de4b2f3ae90c8fc0f17eeaab87d5a951b66ee17
>> > (virtio-net: reset virtqueue affinity when doing cpu hotplug).
>> >
>> > Cc: Rusty Russell <rusty at rustcorp.com.au>
>> > Cc: Michael S. Tsirkin <mst at redhat.com>
>> > Cc: Wanlong Gao <gaowanlong at cn.fujitsu.com>
>> > Acked-by: Michael S. Tsirkin <mst at redhat.com>
>> > Reviewed-by: Wanlong Gao <gaowanlong at cn.fujitsu.com>
>> > Signed-off-by: Jason Wang <jasowang at redhat.com>
>> > ---
>> > The patch is need for 3.8 and above.
>> 
>> Please put 'CC: stable at kernel.org # 3.8+' in the commit.
>
> Not if this is going in through the net tree.
WTF?  Wow, there really *is* an FAQ: https://lwn.net/Articles/561669/

DaveM is the best maintainer I've ever known, but I abhor the idea that
every subsystem has its own incompatible variant on workflow and style.

Asking people to express 'CC: stable' in words is error-prone; if Dave
wants to filter it, he's quite capable.

Rusty.

From: Rusty Russell <rusty at rustcorp.com.au>
Date: Fri, 18 Oct 2013 11:30:15 +1030
> Asking people to express 'CC: stable' in words is error-prone; if
Dave
> wants to filter it, he's quite capable.
Filtering it one time is one thing.

Potentially acting on that filter 100 or so times a day...

That's completely another.