From: Andi Kleen <andi@firstfloor.org>
To: jmerkey@wolfmountaingroup.com
Cc: Andi Kleen <andi@firstfloor.org>,
Jason Wessel <jason.wessel@windriver.com>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Stefan Richter <stefanr@s5r6.in-berlin.de>,
Josh Boyer <jwboyer@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [ANNOUNCE] Merkey's Kernel Debugger
Date: Thu, 7 Aug 2008 18:07:02 +0200 [thread overview]
Message-ID: <20080807160702.GF24801@one.firstfloor.org> (raw)
In-Reply-To: <37747.166.70.238.45.1218113134.squirrel@webmail.wolfmountaingroup.com>
> Also, whoever wrote "/Documentation/volatiles_are_evil" must not have
> worked with the busted-ass GNU compiler that optimizes away global
> variables and busts SMP dependent code. I am not going to remove the
The Linux way to handle this is to use gcc memory barriers.
mb()/barrier()/wmb()/rmb()/smp_rmb()/smp_wmb() etc.
Normally everything that volatile can do can be expressed by them.
On x86 such a memory barrier tells gcc that memory might
have been clobbered and needs to be flushed and also prevents the compiler
from reordering memory accesses. On other architectures it also forces ordering
on the CPU level, although that's not needed on x86 (except
in some special situations like using write-combining)
See Documentation/memory-barriers.txt
-Andi
next prev parent reply other threads:[~2008-08-07 16:06 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-03 17:22 [ANNOUNCE] Merkey's Kernel Debugger jmerkey
[not found] ` <17494.166.70.238.46.1217784156.squirrel@webmail.wolfmountaingroup.com >
2008-08-03 19:36 ` jmerkey
2008-08-03 20:00 ` Rene Herman
2008-08-04 0:14 ` Josh Boyer
2008-08-04 2:19 ` jmerkey
2008-08-04 13:41 ` Stefan Richter
2008-08-04 14:33 ` jmerkey
2008-08-05 9:41 ` Geert Uytterhoeven
2008-08-05 15:02 ` jmerkey
2008-08-05 15:33 ` Nick Piggin
2008-08-05 15:19 ` jmerkey
2008-08-05 15:45 ` Nick Piggin
2008-08-05 15:32 ` jmerkey
2008-08-05 16:38 ` Nick Piggin
2008-08-05 16:45 ` jmerkey
2008-08-06 19:47 ` Rene Herman
2008-08-05 16:04 ` Chris Friesen
2008-08-05 16:39 ` jmerkey
2008-08-07 20:43 ` Daniel Barkalow
2008-08-07 21:02 ` jmerkey
2008-08-07 21:04 ` jmerkey
2008-08-05 17:21 ` Paul Mundt
2008-08-05 17:10 ` jmerkey
2008-08-06 3:08 ` Andi Kleen
2008-08-06 5:50 ` Nick Piggin
2008-08-07 17:45 ` Christoph Lameter
2008-08-07 17:53 ` jmerkey
2008-08-07 18:08 ` Stefan Richter
2008-08-07 19:10 ` Christoph Lameter
2008-08-07 19:47 ` Jay Lan
2008-08-07 19:34 ` jmerkey
2008-08-08 1:26 ` Vivek Goyal
2008-08-07 20:06 ` Andi Kleen
2008-08-07 20:07 ` Bernhard Walle
2008-08-07 20:09 ` Andi Kleen
2008-08-07 20:11 ` Bernhard Walle
2008-08-07 22:28 ` Keith Owens
2008-08-08 1:15 ` Vivek Goyal
2008-08-08 2:29 ` Andi Kleen
2008-08-08 12:08 ` Cliff Wickman
2008-08-08 12:20 ` Andi Kleen
2008-08-08 13:19 ` jmerkey
2008-08-08 15:06 ` Cliff Wickman
2008-08-08 13:29 ` Vivek Goyal
2008-08-08 14:50 ` Cliff Wickman
2008-08-08 16:57 ` Jay Lan
2008-08-11 12:56 ` Vivek Goyal
2008-08-08 18:03 ` Andi Kleen
2008-08-11 13:02 ` Vivek Goyal
2008-08-11 13:11 ` jmerkey
2008-08-11 13:50 ` Andi Kleen
2008-08-11 16:16 ` jmerkey
2008-08-18 9:12 ` Takenori Nagano
2008-08-08 8:40 ` Nick Piggin
2008-08-06 13:11 ` Bill Davidsen
2008-08-06 13:37 ` Stefan Richter
2008-08-06 13:54 ` Olivier Galibert
2008-08-06 13:45 ` jmerkey
2008-08-06 14:16 ` Nick Piggin
2008-08-06 17:21 ` Jason Wessel
2008-08-06 18:57 ` Andi Kleen
2008-08-07 12:45 ` jmerkey
2008-08-07 15:17 ` Peter Zijlstra
2008-08-07 16:07 ` Andi Kleen [this message]
2008-08-07 15:52 ` jmerkey
2008-08-07 17:04 ` Stefan Richter
2008-08-08 0:28 ` Stefan Richter
2008-08-11 10:36 ` jidong xiao
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