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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Jesse Barnes <jbarnes@sgi.com>
Cc: Albert Cahalan <albert@users.sourceforge.net>,
	linux-kernel mailing list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] I/O space write barrier
Date: Tue, 05 Oct 2004 13:04:39 +1000	[thread overview]
Message-ID: <1096945479.24537.15.camel@gaston> (raw)
In-Reply-To: <200410041926.57205.jbarnes@sgi.com>


> I agree, it's hard to get right, especially when you've got a large base of 
> drivers with hard to find assumptions about ordering.
> 
> What about mmiowb()?  Should it be eieio?  I don't want to post another patch 
> if I don't have to...

I don't understand the whole story...

If normal accesses aren't relaxed (and I think they shouldn't be), then
there is no point in a barrier here.... If you need an explicit barrier
for explicitely relaxed accesses, then yes.

That doesn't solve my need of MMIO vs. memory unless you are trying to
cover that as well, in which case it should be a sync.

Ben.



  reply	other threads:[~2004-10-05  3:10 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-04 20:39 [PATCH] I/O space write barrier Albert Cahalan
2004-10-04 21:20 ` Jesse Barnes
2004-10-05  0:32   ` Albert Cahalan
2004-10-05  1:22     ` Benjamin Herrenschmidt
2004-10-05  2:26       ` Jesse Barnes
2004-10-05  3:04         ` Benjamin Herrenschmidt [this message]
2004-10-05 15:33           ` Jesse Barnes
2004-10-05 22:41             ` Benjamin Herrenschmidt
2004-10-05 23:09               ` Jesse Barnes
2004-10-05 23:57               ` Roland Dreier
2004-10-06  1:45                 ` Benjamin Herrenschmidt
2004-10-05  2:33     ` Jesse Barnes
  -- strict thread matches above, loose matches on Subject: below --
2004-10-21 23:13 Jesse Barnes
2004-10-22  1:01 ` Grant Grundler
2004-10-22  3:05   ` Jesse Barnes
2004-10-22  4:26     ` Greg Banks
2004-10-22 15:26     ` Grant Grundler
2004-10-05 22:38 Jesse Barnes
2004-09-27 18:03 Jesse Barnes
2004-09-29 10:36 ` Greg Banks
2004-09-29 20:35   ` David S. Miller
2004-09-29 20:43     ` Jesse Barnes
2004-09-29 20:50       ` David S. Miller
2004-09-30  2:23         ` Greg Banks
2004-09-29 22:55 ` Jesse Barnes
2004-09-30  7:15   ` Jeremy Higdon
2004-09-30 21:21     ` Guennadi Liakhovetski
2004-10-16  0:38       ` Jeremy Higdon
2004-10-16  3:20         ` Matthew Wilcox
2004-10-16  3:31           ` Jeremy Higdon
2004-09-22 15:45 Jesse Barnes

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