From: Olof Johansson <olof@lixom•net>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: [PATCH] Avoid unpaired stwcx. on some processors
Date: Sun, 11 Nov 2007 01:14:38 -0600 [thread overview]
Message-ID: <20071111071438.GA12369@lixom.net> (raw)
In-Reply-To: <1194756365.21340.32.camel@pasglop>
On Sun, Nov 11, 2007 at 03:46:05PM +1100, Benjamin Herrenschmidt wrote:
>
> > Seems like a "better" (but still ugly) workaround would be to create a
> > _new_ reservation to a RA that's unavailable to any userspace process,
> > so that they could never do a successful store to it. That way you would
> > have stray reservations, but never dangling stwcx:es. No?
>
> Many processors don't compare the reservation address locally. If
> there's any valid reservation held by that processor, a subsequent
> stwcx. will always succeed. That would make you scheme dangerous :-)
Yeah, I had missed that arch detail. Becky already explained it in her
reply, but thanks for doing it again. :)
-Olof
next prev parent reply other threads:[~2007-11-11 7:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-09 22:08 [PATCH] Avoid unpaired stwcx. on some processors Becky Bruce
2007-11-09 23:19 ` Olof Johansson
2007-11-09 23:52 ` Becky Bruce
2007-11-10 0:18 ` Olof Johansson
2007-11-11 4:46 ` Benjamin Herrenschmidt
2007-11-11 7:14 ` Olof Johansson [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-11-09 22:17 Becky Bruce
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