linux-kernel - Re: [PATCH] checkpatch: Make the memory barrier test noisier

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: <20130928075409.GK15690@laptop.programming.kicks-ass.net>
Date:	Sat, 28 Sep 2013 09:54:09 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Oliver Neukum <oliver@...kum.org>
Cc:	Joe Perches <joe@...ches.com>, Ingo Molnar <mingo@...nel.org>,
	Tim Chen <tim.c.chen@...ux.intel.com>,
	Jason Low <jason.low2@...com>,
	Davidlohr Bueso <davidlohr@...com>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Alex Shi <alex.shi@...aro.org>,
	Andi Kleen <andi@...stfloor.org>,
	Michel Lespinasse <walken@...gle.com>,
	Davidlohr Bueso <davidlohr.bueso@...com>,
	Matthew R Wilcox <matthew.r.wilcox@...el.com>,
	Dave Hansen <dave.hansen@...el.com>,
	Rik van Riel <riel@...hat.com>,
	Peter Hurley <peter@...leysoftware.com>,
	linux-kernel@...r.kernel.org, linux-mm <linux-mm@...ck.org>
Subject: Re: [PATCH] checkpatch: Make the memory barrier test noisier

On Sat, Sep 28, 2013 at 01:40:27AM +0200, Oliver Neukum wrote:
> On Fri, 2013-09-27 at 16:50 +0200, Peter Zijlstra wrote:
> > On Fri, Sep 27, 2013 at 07:34:55AM -0700, Joe Perches wrote:
> > > That would make it seem as if all barriers are SMP no?
> > 
> > I would think any memory barrier is ordering against someone else; if
> > not smp then a device/hardware -- like for instance the hardware page
> > table walker.
> > 
> > Barriers are fundamentally about order; and order only makes sense if
> > there's more than 1 party to the game.
> 
> But not necessarily more than 1 kind of parties. It is perfectly
> possible to have a barrier against other threads running the same
> function.

Then that makes a good comment ;-)
--
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/