linux-kernel - Re: Is gcc thread-unsafe?

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: <20071024204631.7e7e3c47@laptopd505.fenrus.org>
Date:	Wed, 24 Oct 2007 20:46:31 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Nick Piggin <nickpiggin@...oo.com.au>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"Kleen, Andi" <ak@...e.de>
Subject: Re: Is gcc thread-unsafe?

On Thu, 25 Oct 2007 13:24:49 +1000
Nick Piggin <nickpiggin@...oo.com.au> wrote:

> Hi,
> 
> Andi spotted this exchange on the gcc list. I don't think he's
> brought it up here yet, but it worries me enough that I'd like
> to discuss it.
> 
> Starts here
> http://gcc.gnu.org/ml/gcc/2007-10/msg00266.html
> 
> Concrete example here
> http://gcc.gnu.org/ml/gcc/2007-10/msg00275.html
> 
> Basically, what the gcc developers are saying is that gcc is
> free to load and store to any memory location, so long as it
> behaves as if the instructions were executed in sequence.
> 

this optimization btw is a serious mis-optimization, it makes memory
more dirty and causes cachelines to become unshared.... I'm sure it
works great on microbenchmarks but it sucks bigtime for anything real
-
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/