From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Jes Sorensen <jes@sgi.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Jeremy Higdon <jeremy@sgi.com>, Roland Dreier <rdreier@cisco.com>,
Arjan van de Ven <arjan@infradead.org>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
tpiepho@freescale.com, linuxppc-dev@ozlabs.org,
scottwood@freescale.com, torvalds@linux-foundation.org,
David Miller <davem@davemloft.net>,
alan@lxorguk.ukuu.org.uk
Subject: Re: MMIO and gcc re-ordering issue
Date: Thu, 05 Jun 2008 18:43:53 +1000 [thread overview]
Message-ID: <1212655433.9496.109.camel@pasglop> (raw)
In-Reply-To: <4847A690.302@sgi.com>
On Thu, 2008-06-05 at 10:40 +0200, Jes Sorensen wrote:
> Jesse Barnes wrote:
> > Now, in hindsight, using a PIO write set & test flag approach in
> > writeX/spin_unlock (ala powerpc) might have been a better approach, but iirc
> > that never came up in the discussion, probably because we were focused on PCI
> > posting and not uncached vs. cached ordering.
>
> Hi Jesse,
>
> I am going to take a stab at implementing this so we can see how much
> of an impact it will have.
Note that the powerpc implementation currently clears the flag
on spin_lock and tests it on unlock. We are considering changing
that to not touch the flag on spin_lock and just clear it whenever
we do a sync (ie, on unlock, on explicit mmiowb, and possibly even
on readl's where we happen to do sync's).
Ben.
next prev parent reply other threads:[~2008-06-05 8:44 UTC|newest]
Thread overview: 148+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4833524C.3040207@freescale.com>
[not found] ` <20080520.153947.84346222.davem@davemloft.net>
[not found] ` <4833542E.3040608@freescale.com>
[not found] ` <20080520.155326.195407196.davem@davemloft.net>
[not found] ` <1211516683.8297.271.camel@pasglop>
[not found] ` <Pine.LNX.4.64.0805221553400.8205@t2.domain.actdsltmp>
2008-05-27 1:33 ` MMIO and gcc re-ordering issue Benjamin Herrenschmidt
2008-05-27 1:40 ` David Miller
2008-05-27 2:15 ` Benjamin Herrenschmidt
2008-05-27 2:28 ` David Miller
2008-05-27 3:39 ` Benjamin Herrenschmidt
2008-05-27 15:35 ` Linus Torvalds
2008-05-27 15:35 ` Linus Torvalds
2008-05-27 16:47 ` Linus Torvalds
2008-05-27 17:31 ` Linus Torvalds
2008-06-02 10:36 ` Ingo Molnar
2008-06-02 21:53 ` Benjamin Herrenschmidt
2008-05-27 21:12 ` Benjamin Herrenschmidt
2008-05-27 18:23 ` Trent Piepho
2008-05-27 18:33 ` Scott Wood
2008-05-27 21:10 ` Benjamin Herrenschmidt
2008-05-27 21:30 ` Linus Torvalds
2008-05-27 21:38 ` Alan Cox
2008-05-27 21:53 ` Matthew Wilcox
2008-05-27 21:46 ` Alan Cox
2008-05-27 22:02 ` Linus Torvalds
2008-05-27 21:59 ` Linus Torvalds
2008-05-27 21:38 ` Benjamin Herrenschmidt
2008-05-27 21:42 ` Matthew Wilcox
2008-05-27 22:17 ` Benjamin Herrenschmidt
2008-05-28 8:36 ` Haavard Skinnemoen
2008-05-29 11:05 ` Pantelis Antoniou
2008-05-30 1:13 ` Benjamin Herrenschmidt
2008-05-30 6:07 ` Haavard Skinnemoen
2008-05-30 7:24 ` Benjamin Herrenschmidt
2008-05-30 8:27 ` Haavard Skinnemoen
2008-05-30 9:22 ` Geert Uytterhoeven
2008-06-02 8:11 ` Haavard Skinnemoen
2008-06-02 15:48 ` Scott Wood
2008-06-03 7:46 ` Haavard Skinnemoen
2008-06-04 15:31 ` Linus Torvalds
2008-05-27 21:55 ` Linus Torvalds
2008-05-27 22:19 ` Benjamin Herrenschmidt
2008-05-29 7:10 ` Arnd Bergmann
2008-05-29 7:10 ` Arnd Bergmann
2008-05-29 10:46 ` Alan Cox
2008-06-02 7:24 ` Russell King
2008-06-02 7:24 ` Russell King
2008-06-03 4:16 ` Nick Piggin
2008-06-03 4:16 ` Nick Piggin
2008-06-03 4:32 ` Benjamin Herrenschmidt
2008-06-03 6:11 ` Nick Piggin
2008-06-03 6:48 ` Benjamin Herrenschmidt
2008-06-03 6:53 ` Paul Mackerras
2008-06-03 7:18 ` Nick Piggin
2008-06-03 7:18 ` Nick Piggin
2008-06-03 14:47 ` Linus Torvalds
2008-06-03 18:47 ` Trent Piepho
2008-06-03 18:55 ` Matthew Wilcox
2008-06-03 19:57 ` Trent Piepho
2008-06-03 21:35 ` Matthew Wilcox
2008-06-03 21:58 ` Trent Piepho
2008-06-04 2:00 ` Nick Piggin
2008-06-03 19:07 ` Linus Torvalds
2008-06-04 2:05 ` Nick Piggin
2008-06-04 2:46 ` Linus Torvalds
2008-06-04 11:47 ` Alan Cox
2008-06-04 11:47 ` Alan Cox
2008-06-10 6:56 ` Nick Piggin
2008-06-10 17:41 ` Jesse Barnes
2008-06-10 18:10 ` James Bottomley
2008-06-10 19:05 ` Roland Dreier
2008-06-10 19:19 ` Jesse Barnes
2008-06-11 3:29 ` Nick Piggin
2008-06-11 3:29 ` Nick Piggin
2008-06-11 3:40 ` Benjamin Herrenschmidt
2008-06-11 4:06 ` Nick Piggin
2008-06-11 16:07 ` Jesse Barnes
2008-06-11 16:07 ` Jesse Barnes
2008-06-12 11:27 ` Nick Piggin
2008-06-11 4:18 ` Paul Mackerras
2008-06-11 5:00 ` Nick Piggin
2008-06-11 5:13 ` Paul Mackerras
2008-06-11 5:35 ` Nick Piggin
2008-06-11 6:02 ` Nick Piggin
2008-06-12 12:14 ` Paul Mackerras
2008-06-12 13:08 ` Nick Piggin
2008-06-11 14:46 ` Linus Torvalds
2008-06-11 5:20 ` Paul Mackerras
2008-06-11 5:20 ` Paul Mackerras
2008-06-04 2:19 ` Nick Piggin
2008-06-03 19:43 ` Trent Piepho
2008-06-03 21:33 ` Matthew Wilcox
2008-06-03 21:44 ` Trent Piepho
2008-06-04 2:25 ` Nick Piggin
2008-06-04 2:25 ` Nick Piggin
2008-06-04 6:39 ` Trent Piepho
2008-06-03 22:26 ` Benjamin Herrenschmidt
2008-05-27 3:42 ` Arjan van de Ven
2008-05-27 4:08 ` Roland Dreier
2008-05-27 4:20 ` Arjan van de Ven
2008-05-27 7:08 ` Benjamin Herrenschmidt
2008-05-27 7:08 ` Benjamin Herrenschmidt
2008-05-27 15:50 ` Roland Dreier
2008-05-27 16:37 ` James Bottomley
2008-05-27 17:38 ` Roland Dreier
2008-05-27 17:53 ` James Bottomley
2008-05-27 18:07 ` Roland Dreier
2008-05-27 18:17 ` Roland Dreier
2008-05-27 21:23 ` Chris Friesen
2008-05-27 21:23 ` Chris Friesen
2008-05-27 21:29 ` Roland Dreier
2008-05-27 23:04 ` Paul Mackerras
2008-05-27 21:11 ` Benjamin Herrenschmidt
2008-05-27 21:33 ` Roland Dreier
2008-05-27 22:13 ` Benjamin Herrenschmidt
2008-05-27 22:39 ` Roland Dreier
2008-05-29 14:47 ` Jes Sorensen
2008-05-29 15:01 ` James Bottomley
2008-05-30 9:36 ` Jes Sorensen
2008-05-30 17:21 ` Jesse Barnes
2008-05-30 17:21 ` Jesse Barnes
2008-05-31 7:57 ` Jeremy Higdon
2008-05-29 21:40 ` Benjamin Herrenschmidt
2008-05-29 21:48 ` Trent Piepho
2008-05-29 22:05 ` Benjamin Herrenschmidt
2008-05-30 1:53 ` Trent Piepho
2008-05-29 21:53 ` Jesse Barnes
2008-05-29 21:53 ` Jesse Barnes
2008-05-30 9:39 ` Jes Sorensen
2008-05-30 9:48 ` Jes Sorensen
2008-05-31 8:14 ` Pavel Machek
2008-06-02 9:48 ` Jes Sorensen
2008-05-29 22:06 ` Roland Dreier
2008-05-29 22:25 ` Trent Piepho
2008-05-29 22:25 ` Trent Piepho
2008-05-30 3:56 ` Paul Mackerras
2008-05-31 7:52 ` Jeremy Higdon
2008-06-02 9:56 ` Jes Sorensen
2008-06-02 21:02 ` Jeremy Higdon
2008-06-03 4:33 ` Nick Piggin
2008-06-03 8:15 ` Jeremy Higdon
2008-06-03 8:15 ` Jeremy Higdon
2008-06-03 8:19 ` Nick Piggin
2008-06-03 8:45 ` Jeremy Higdon
2008-06-03 16:52 ` Jesse Barnes
2008-06-03 16:52 ` Jesse Barnes
2008-06-05 8:40 ` Jes Sorensen
2008-06-05 8:43 ` Benjamin Herrenschmidt [this message]
2008-06-12 15:07 ` Matthew Wilcox
2008-06-13 0:07 ` Benjamin Herrenschmidt
2008-05-31 8:04 ` Pavel Machek
2008-05-27 8:24 ` Alan Cox
2008-05-27 15:28 ` Jonathan Corbet
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