Re: [PATCH] bonding: replace system timer with work queue

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Wed, 28 Feb 2007 10:12:01 +0100 (CET)
Jaroslav Kysela <perex@suse.cz> wrote:

> Hi,
> 
> 	please, review and apply to mm tree for further testing. The patch 
> is also available at 
> ftp://ftp.alsa-project.org/pub/kernel-patches/bonding-workqueue.patch .
> 
> 					Thank you,
> 						Jaroslav
> 

You should submit network patches to the entry in the MAINTAINERS file.

BONDING DRIVER
P:	Chad Tindel
M:	ctindel@users.sourceforge.net
P:	Jay Vosburgh
M:	fubar@us.ibm.com
L:	bonding-devel@lists.sourceforge.net
W:	http://sourceforge.net/projects/bonding/
S:	Supported


> @@ -3569,20 +3552,20 @@ static int bond_close(struct net_device 
>  	 */
>  
>  	if (bond->params.miimon) {  /* link check interval, in milliseconds. */
> -		del_timer_sync(&bond->mii_timer);
> +		cancel_rearming_delayed_workqueue(bond_wq, &bond->mii_work);
>  	}
>  
>  	if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
> -		del_timer_sync(&bond->arp_timer);
> +		cancel_rearming_delayed_workqueue(bond_wq, &bond->arp_work);
>  	}
>  
>  	switch (bond->params.mode) {
>  	case BOND_MODE_8023AD:
> -		del_timer_sync(&(BOND_AD_INFO(bond).ad_timer));
> +		cancel_rearming_delayed_workqueue(bond_wq, &(BOND_AD_INFO(bond).ad_work));
>  		break;
>  	case BOND_MODE_TLB:
>  	case BOND_MODE_ALB:
> -		del_timer_sync(&(BOND_ALB_INFO(bond).alb_timer));
> +		cancel_rearming_delayed_workqueue(bond_wq, &(BOND_ALB_INFO(bond).alb_work));
>  		break;
>  	default:
>  		break;


This part will deadlock since it is not safe to cancel a workqueue
entry with RTNL mutex held. The cancel operation has to wait for the workqueue
to run, and the entry being run maybe stuck waiting for the RTNL.



-- 
Stephen Hemminger <shemminger@linux-foundation.org>