RE: [PATCH] Re: [2.6.21.1] soft lockup when removing netconsole module

["Wessel, Jason" <jason.wessel@windriver.com>]

> -----Original Message-----
> From: Andrew Morton [mailto:akpm@linux-foundation.org] 
> > 
> > Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
> > 
> > ---
> > 
> > diff -Nurp 2.6.21-/net/core/netpoll.c 2.6.21/net/core/netpoll.c
> > --- 2.6.21-/net/core/netpoll.c	2007-04-26 
> 15:08:32.000000000 +0200
> > +++ 2.6.21/net/core/netpoll.c	2007-06-12 
> 21:05:23.000000000 +0200
> > @@ -73,7 +73,8 @@ static void queue_process(struct work_st
> >  			netif_tx_unlock(dev);
> >  			local_irq_restore(flags);
> >  
> > -			schedule_delayed_work(&npinfo->tx_work, HZ/10);
> > +			if (atomic_read(&npinfo->refcnt))
> > +				
> schedule_delayed_work(&npinfo->tx_work, HZ/10);
> >  			return;
> >  		}
> >  		netif_tx_unlock(dev);
> > @@ -780,9 +781,15 @@ void netpoll_cleanup(struct netpoll *np)
> >  			if (atomic_dec_and_test(&npinfo->refcnt)) {
> >  				skb_queue_purge(&npinfo->arp_tx);
> >  				skb_queue_purge(&npinfo->txq);
> > -				
> cancel_rearming_delayed_work(&npinfo->tx_work);
> > +				cancel_delayed_work(&npinfo->tx_work);
> >  				flush_scheduled_work();
> >  
> > +				/* clean after last, unfinished work */
> > +				if (!skb_queue_empty(&npinfo->txq)) {
> > +					struct sk_buff *skb;
> > +					skb = 
> __skb_dequeue(&npinfo->txq);
> > +					kfree_skb(skb);
> > +				}
> >  				kfree(npinfo);
> >  			}
> >  		}
> 
> Everything went quiet?
> 
> If this patch has been tested and fixes the bug, can you 
> please send a version which is ready for merging?  (ie: add a 
> suitable description of what it does).
> 
> 

I mailed Jarek separately.

I had tested the patch with netconsole and kgdb and it does in fact fix
the problem that was reported.

Jason.