[ofa-general] Re: [PATCH 2/3][NET_BATCH] net core use batching

[David Miller]

From: Herbert Xu <herbert at gondor.apana.org.au>
Date: Tue, 9 Oct 2007 10:04:42 +0800

> On Tue, Oct 09, 2007 at 10:03:18AM +0800, Herbert Xu wrote:
> > On Tue, Oct 09, 2007 at 10:01:15AM +0800, Herbert Xu wrote:
> > > On Mon, Oct 08, 2007 at 06:41:26PM -0700, David Miller wrote:
> > > >
> > > > I also want to point out another issue.  Any argument wrt. reordering
> > > > is specious at best because right now reordering from qdisc to device
> > > > happens anyways.
> > > 
> > > This is not true.
> > > 
> > > If your device has a qdisc at all, then you will end up in the
> > > function qdisc_restart, where we release the queue lock only
> > > after acquiring the TX lock.
> > > 
> > > So right now this path does not create any reordering.
> > 
> > Argh! Someone's just broken this.  I think we should restore
> > the original behaviour.
> 
> Please revert
> 
> commit 41843197b17bdfb1f97af0a87c06d24c1620ba90
> Author: Jamal Hadi Salim <hadi at cyberus.ca>
> Date:   Tue Sep 25 19:27:13 2007 -0700
> 
>     [NET_SCHED]: explict hold dev tx lock
> 
> As this change introduces potential reordering and I don't think
> we've discussed this aspect sufficiently.

Agreed, and done.