linux-kernel - Re: [PATCH RFC tip/core/rcu 24/28] rcu: Introduce bulk reference count

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: <1322505327.2921.156.camel@twins>
Date:	Mon, 28 Nov 2011 19:35:27 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	paulmck@...ux.vnet.ibm.com
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu, laijs@...fujitsu.com,
	dipankar@...ibm.com, akpm@...ux-foundation.org,
	mathieu.desnoyers@...ymtl.ca, josh@...htriplett.org,
	niv@...ibm.com, tglx@...utronix.de, rostedt@...dmis.org,
	Valdis.Kletnieks@...edu, dhowells@...hat.com,
	eric.dumazet@...il.com, darren@...art.com, patches@...aro.org
Subject: Re: [PATCH RFC tip/core/rcu 24/28] rcu: Introduce bulk reference
 count

On Mon, 2011-11-28 at 10:31 -0800, Paul E. McKenney wrote:
> >   local_irq_save(flags);
> >   srcu_read_lock(&my_srcu_domain);
> >   local_irq_restore(flags);
> > 
> > and
> > 
> >   local_irq_save(flags);
> >   srcu_read_unlock(&my_srcu_domain);
> >   local_irq_restore(flags)
> > 
> > Doesn't look to be too hard, or confusing.
> 
> Ah, OK, I was under the mistaken impression that lockdep would splat
> if you did (for example) srcu_read_lock() in an exception handler and
> srcu_read_unlock() in the context of the task that took the exception. 

I don't think it will, lockdep does very little actual validation on the
RCU locks other than recording they're held. But if they do, the planned
TODO item will get inversed.

Should be easy enough to test I guess.
--
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/