netdev - Re: [rfc] IPVS: convert scheduler management to RCU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100821032832.GB8616@verge.net.au>
Date:	Sat, 21 Aug 2010 12:28:32 +0900
From:	Simon Horman <horms@...ge.net.au>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:	lvs-devel@...r.kernel.org, netdev@...r.kernel.org,
	netfilter-devel@...r.kernel.org,
	Stephen Hemminger <shemminger@...tta.com>,
	Wensong Zhang <wensong@...ux-vs.org>,
	Julian Anastasov <ja@....bg>
Subject: Re: [rfc] IPVS: convert scheduler management to RCU

On Fri, Aug 20, 2010 at 12:29:00PM -0700, Paul E. McKenney wrote:
> On Fri, Aug 20, 2010 at 10:59:19PM +0900, Simon Horman wrote:
> > On Fri, Aug 20, 2010 at 10:33:21PM +0900, Simon Horman wrote:
> > > Signed-off-by: Simon Horman <horms@...ge.net.au>

[ snip ]

> > > @@ -223,8 +223,8 @@ int unregister_ip_vs_scheduler(struct ip
> > >  	/*
> > >  	 *	Remove it from the d-linked scheduler list
> > >  	 */
> > > -	list_del(&scheduler->n_list);
> > > -	write_unlock_bh(&__ip_vs_sched_lock);
> > > +	list_del_rcu(&scheduler->n_list);
> > > +	spin_unlock_bh(&ip_vs_sched_mutex);
> > 
> > On further reading, I believe that I need a synchronize_rcu(); here,
> 
> Good catch!

:-)

> However, you actually need synchronize_rcu_bh() to match your
> rcu_read_lock_bh() calls.  Also, given Julian's comment, you probably
> need something to show that this conversion is a real improvement.

Thanks.  As suggested by Julian and others, I've decided to just
use a spinlock and not use RCU for this.

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