linux-kernel - Re: [PATCH] rcu: Is it safe to enter an RCU read-side critical section?

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]

Date:	Mon, 9 Sep 2013 06:53:20 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Frederic Weisbecker <fweisbec@...il.com>,
	Eric Dumazet <eric.dumazet@...il.com>,
	linux-kernel@...r.kernel.org, mingo@...e.hu, laijs@...fujitsu.com,
	dipankar@...ibm.com, akpm@...ux-foundation.org,
	mathieu.desnoyers@...icios.com, josh@...htriplett.org,
	niv@...ibm.com, tglx@...utronix.de, rostedt@...dmis.org,
	dhowells@...hat.com, edumazet@...gle.com, darren@...art.com,
	sbw@....edu, cl@...ux.com
Subject: Re: [PATCH] rcu: Is it safe to enter an RCU read-side critical
 section?

On Mon, Sep 09, 2013 at 03:36:04PM +0200, Peter Zijlstra wrote:
> On Mon, Sep 09, 2013 at 06:23:43AM -0700, Paul E. McKenney wrote:
> > And guys, I have to say that the advice on which per-CPU primitive to use
> > varies wildly and randomly.  For all I know, each of you individually
> > might well be sticking to the same story, but taken together, your
> > collective advice is strongly resembling white noise.
> 
> Its partly because cl and I disagree on things. He doesn't seem to care
> much about validation and believes that people will not make mistakes
> with this stuff.

At some point, my only recourse would be to require an Acked-by from one
of you for any per-CPU changes proposed by the other.  I really hope that
it doesn't come to that, but this situation is getting a bit annoying.

> And partly because I didn't get what was going on. While Frederic's
> explanation might be correct it was incomprehensible for me.

And I freely admit that the comments on rcu_is_cpu_idle() are completely
inadequate, and I do apologize for that.  Seemed clear at the time.
But then it always does, doesn't it?  ;-)

							Thanx, Paul

--
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/