Re: Opteron Rev E has a bug ... a locked instruction doesn't act as a read-acquire barrier (confirmed)

[Arkadiusz Miskiewicz]

On Wednesday 06 August 2008, Mikael Pettersson wrote:
> On Wed, 6 Aug 2008 19:13:34 +0200, Arkadiusz Miskiewicz wrote:
> >On Wednesday 06 August 2008, Wahlig, Elsie wrote:
> >> Your issue may be one that has been seen on 1st generation
> >> AMD Opteron processor's with cpuid family 0Fh, cpuid model's
> >> < 40h with the code sequence that performs a read-modify write
> >> operation after acquiring a semaphore.
[...]
> Also I think I'll start by writing a user-space test program that
> does a stress-test of the plain lock;rmw;unlobk sequence to see if
> it can break it. (Locks/mutexes are also used in user-space.)

Bugreported so hopefully it won't be lost.

http://bugzilla.kernel.org/show_bug.cgi?id=11305

> /Mikael

-- 
Arkadiusz MiÅkiewicz        PLD/Linux Team
arekm / maven.pl            http://ftp.pld-linux.org/
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