linux-kernel - Re: [block IO crash] Re: 2.6.39-rc5-git2 boot crashs

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: <BANLkTi=efcVkGb+DReZ+i1p5j4QXJYjKjQ@mail.gmail.com>
Date:	Wed, 4 May 2011 12:38:28 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Christoph Lameter <cl@...ux.com>
Cc:	Pekka Enberg <penberg@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tejun Heo <tj@...nel.org>, Ingo Molnar <mingo@...e.hu>,
	Jens Axboe <axboe@...nel.dk>,
	Andrew Morton <akpm@...ux-foundation.org>,
	werner <w.landgraf@...ru>, "H. Peter Anvin" <hpa@...or.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [block IO crash] Re: 2.6.39-rc5-git2 boot crashs

On Wed, May 4, 2011 at 12:30 PM, Christoph Lameter <cl@...ux.com> wrote:
>
> The naming convention came about from the existing this_cpu_xxx
> operations

You're missing my point.

An "add" operation makes sense even if it isn't atomic, because
atomicity isn't a part of the definition of "add".

But cmpxchg DOES NOT MAKE SENSE without atomicity guarantees.

The whole operation is about atomicity.

Having a version that isn't atomic is STUPID. It's misleading. It's _wrong_.

In contrast, having a non-atomic "add" version is understandable.

So when  you say "naming convention", you're missing the much bigger
naming convention. Namely the "cmpxchg" part!

                           Linus
--
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/