Patchwork [BUG] net: cpu offline cause napi stall

login
register
mail settings
Submitter Heiko Carstens
Date June 1, 2011, 8:42 p.m.
Message ID <20110601204233.GA2410@osiris.boeblingen.de.ibm.com>
Download mbox | patch
Permalink /patch/98263/
State RFC
Delegated to: David Miller
Headers show

Comments

Heiko Carstens - June 1, 2011, 8:42 p.m.
On Wed, Jun 01, 2011 at 10:03:12PM +0200, Eric Dumazet wrote:
> Le mercredi 01 juin 2011 à 20:12 +0200, Heiko Carstens a écrit :
> > On Wed, Jun 01, 2011 at 06:55:21PM +0200, Eric Dumazet wrote:
> > > > +	/* Append NAPI poll list from offline CPU. */
> > > > +	list_splice_init(&oldsd->poll_list, &sd->poll_list);
> > > >  
> > > >  	raise_softirq_irqoff(NET_TX_SOFTIRQ);
> > > >  	local_irq_enable();
> > > 
> > > Please make sure we raise NET_RX_SOFTIRQ on new cpu if necessary.
> > 
> > Well, see two lines below the list_splice_init() call ;)
> 
> I see nothing... NET_TX_SOFTIRQ and NET_RX_SOFTIRQ are not the same 

Indeed. I must be blind.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Miller - June 6, 2011, 9:50 p.m.
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Wed, 1 Jun 2011 22:42:34 +0200

> On Wed, Jun 01, 2011 at 10:03:12PM +0200, Eric Dumazet wrote:
>> Le mercredi 01 juin 2011 à 20:12 +0200, Heiko Carstens a écrit :
>> > On Wed, Jun 01, 2011 at 06:55:21PM +0200, Eric Dumazet wrote:
>> > > > +	/* Append NAPI poll list from offline CPU. */
>> > > > +	list_splice_init(&oldsd->poll_list, &sd->poll_list);
>> > > >  
>> > > >  	raise_softirq_irqoff(NET_TX_SOFTIRQ);
>> > > >  	local_irq_enable();
>> > > 
>> > > Please make sure we raise NET_RX_SOFTIRQ on new cpu if necessary.
>> > 
>> > Well, see two lines below the list_splice_init() call ;)
>> 
>> I see nothing... NET_TX_SOFTIRQ and NET_RX_SOFTIRQ are not the same 
> 
> Indeed. I must be blind.

Can I get a final version of this patch with proper commit log message,
signoffs, etc.?

Thanks!
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 6561021..6189dac 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5981,6 +5981,11 @@  static int dev_cpu_callback(struct notifier_block *nfb,
 		oldsd->output_queue = NULL;
 		oldsd->output_queue_tailp = &oldsd->output_queue;
 	}
+	/* Append NAPI poll list from offline CPU. */
+	if (!list_empty(&oldsd->poll_list)) {
+		list_splice_init(&oldsd->poll_list, &sd->poll_list);
+		raise_softirq_irqoff(NET_RX_SOFTIRQ);
+	}
 
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_enable();