From: Arjan van de Ven <arjan@infradead.org>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Kleen, Andi" <ak@suse.de>
Subject: Re: Is gcc thread-unsafe?
Date: Wed, 24 Oct 2007 20:46:31 -0700 [thread overview]
Message-ID: <20071024204631.7e7e3c47@laptopd505.fenrus.org> (raw)
In-Reply-To: <200710251324.49888.nickpiggin@yahoo.com.au>
On Thu, 25 Oct 2007 13:24:49 +1000
Nick Piggin <nickpiggin@yahoo.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
next prev parent reply other threads:[~2007-10-25 3:50 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-25 3:24 Nick Piggin
2007-10-25 3:46 ` Arjan van de Ven [this message]
2007-10-25 3:58 ` Nick Piggin
2007-10-25 4:29 ` David Schwartz
2007-10-25 4:35 ` Arjan van de Ven
2007-10-25 18:45 ` Måns Rullgård
2007-10-25 4:47 ` Nick Piggin
2007-10-25 9:40 ` Samuel Tardieu
2007-10-25 9:44 ` Samuel Tardieu
2007-10-25 9:54 ` Samuel Tardieu
2007-10-25 9:55 ` Andi Kleen
2007-10-25 7:15 ` Andi Kleen
2007-10-25 11:58 ` linux-os (Dick Johnson)
2007-10-25 12:16 ` Andi Kleen
2007-10-25 22:49 ` Nick Piggin
2007-10-25 23:09 ` Andi Kleen
2007-10-25 23:14 ` Linus Torvalds
2007-10-25 23:16 ` Andi Kleen
2007-10-25 23:32 ` Linus Torvalds
2007-10-25 23:42 ` Andi Kleen
2007-10-25 23:57 ` Linus Torvalds
2007-10-26 1:15 ` Zachary Amsden
2007-10-26 4:57 ` Willy Tarreau
2007-10-25 23:43 ` Nick Piggin
2007-10-25 23:55 ` Andi Kleen
2007-10-25 23:57 ` Nick Piggin
2007-10-25 14:55 ` Linus Torvalds
2007-10-25 15:12 ` Pekka Enberg
2007-10-25 21:42 ` David Schwartz
2007-10-25 23:22 ` Nick Piggin
2007-10-26 11:59 ` Andrew Haley
2007-10-26 17:39 ` Chris Friesen
2007-10-26 11:59 ` Andrew Haley
2007-10-25 22:26 ` Ismail Dönmez
2007-10-25 22:56 ` Jeff Garzik
2007-10-25 23:04 ` Jeff Garzik
2007-10-31 22:10 ` Phillip Susi
[not found] <fa.JbRGo0cQWncrcfKHmiNdvchsA50@ifi.uio.no>
[not found] ` <fa.8qDECVaPIo7DWbjhQbyw6N5Infg@ifi.uio.no>
[not found] ` <fa.M4DOMggyrQmdTqekWSuw4xCxiTc@ifi.uio.no>
2007-10-25 23:27 ` Robert Hancock
[not found] <e2e108260710260729x4603211cgb68d7434ce1e54e9@mail.gmail.com>
2007-10-26 14:40 ` Bart Van Assche
2007-10-26 15:09 ` Linus Torvalds
2007-10-26 15:34 ` Andrew Haley
2007-10-26 18:06 ` David Schwartz
2007-10-30 10:20 ` Andrew Haley
2007-11-02 15:29 ` Bart Van Assche
2007-11-02 15:38 ` Andrew Haley
2007-11-04 15:13 ` Bart Van Assche
2007-11-04 17:45 ` Linus Torvalds
2007-11-04 17:58 ` Andrew Haley
2007-11-04 18:06 ` Bart Van Assche
2007-11-02 17:18 ` David Schwartz
2007-10-26 21:45 ` Giacomo Catenazzi
2007-10-26 22:24 ` Linus Torvalds
2007-10-26 15:27 ` Linus Torvalds
2007-10-26 16:28 ` Linus Torvalds
2007-10-26 17:07 ` Bart Van Assche
2007-10-26 17:12 ` Andrew Haley
2007-10-26 17:25 ` Linus Torvalds
2007-10-26 18:08 ` Alan Cox
2007-10-26 18:14 ` Linus Torvalds
2007-10-26 20:39 ` Andi Kleen
2007-10-28 18:19 linux
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