linux-kernel - Re: 2.6.26-rc4: RIP __call_for_each

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20080528115238.GB1283@gandalf.sssup.it>
Date:	Wed, 28 May 2008 13:52:38 +0200
From:	Fabio Checconi <fchecconi@...il.com>
To:	Jens Axboe <jens.axboe@...cle.com>
Cc:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Alexey Dobriyan <adobriyan@...il.com>, torvalds@...l.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: 2.6.26-rc4: RIP __call_for_each_cic+0x20/0x50

> From: Jens Axboe <jens.axboe@...cle.com>
> Date: Wed, May 28, 2008 12:07:21PM +0200
>
> On Tue, May 27 2008, Paul E. McKenney wrote:
> > o	When calling cfq_slab_kill(), for example from cfq_exit(),
> > 	what ensures that all previous RCU callbacks have completed?
> > 	
> > 	I suspect that you need an rcu_barrier() at the beginning
> > 	of cfq_slab_kill(), but I could be missing something.
> 
> So we have two callers of that, one is from the error path at init time
> and is obviously ok. The other does need rcu_barrier()! I'll add that.
> 

But isn't the ioc_gone completion (notified only when there are no more
cic allocated) assuring that cfq_slab_kill() is called only after all
the rcu callbacks are completed?  This should avoid the need for the
rcu_barrier().
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/