From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
David Miller <davem@davemloft.net>,
jeff@garzik.org, paulus@samba.org, torvalds@osdl.org,
linux-kernel@vger.kernel.org, akpm@osdl.org,
segher@kernel.crashing.org
Subject: Re: Opinion on ordering of writel vs. stores to RAM
Date: Mon, 11 Sep 2006 08:18:28 +1000 [thread overview]
Message-ID: <1157926708.31071.259.camel@localhost.localdomain> (raw)
In-Reply-To: <1157926993.23085.29.camel@localhost.localdomain>
On Sun, 2006-09-10 at 23:23 +0100, Alan Cox wrote:
> Ar Llu, 2006-09-11 am 07:25 +1000, ysgrifennodd Benjamin Herrenschmidt:
> > I'm copying that from a private discussion I had. Please let me know if
> > you have comments. This proposal includes some questions too so please
> > answer :)
>
> Looks sane and Linus seems to like mmiowb. Only other question: what are
> the guarantees of memcpy_to/fromio. Does it access the memory in ordered
> fashion or not, does it guarantee only ordering at the end of the copy
> or during it ?
Well, Linus is also ok with writel not ordering memory an IO accesses :)
Though he also mentioned that if we go that route (which is what we have
now in fact), we take the burden of having to test and fix drivers who
don't get it...
That's why I think a compromise is in order, thus my proposal :)
Ben.
next prev parent reply other threads:[~2006-09-10 22:21 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-09 2:03 Opinion on ordering of writel vs. stores to RAM Paul Mackerras
2006-09-09 2:42 ` Linus Torvalds
2006-09-09 3:02 ` Paul Mackerras
2006-09-09 3:54 ` Linus Torvalds
2006-09-09 7:24 ` Benjamin Herrenschmidt
2006-09-09 9:34 ` David Miller
2006-09-09 9:55 ` Jeff Garzik
2006-09-09 10:08 ` David Miller
2006-09-10 17:18 ` Jesse Barnes
2006-09-10 19:35 ` Alan Cox
2006-09-10 21:25 ` Benjamin Herrenschmidt
2006-09-10 22:23 ` Alan Cox
2006-09-10 22:18 ` Benjamin Herrenschmidt [this message]
2006-09-11 13:19 ` Jes Sorensen
2006-09-10 23:35 ` Segher Boessenkool
2006-09-11 0:12 ` Benjamin Herrenschmidt
2006-09-11 0:34 ` Jesse Barnes
2006-09-11 1:04 ` Benjamin Herrenschmidt
2006-09-11 1:13 ` Segher Boessenkool
2006-09-11 1:35 ` Benjamin Herrenschmidt
2006-09-11 9:02 ` Alan Cox
2006-09-11 9:23 ` Benjamin Herrenschmidt
2006-09-11 0:25 ` Jesse Barnes
2006-09-11 0:54 ` Segher Boessenkool
2006-09-11 1:10 ` Benjamin Herrenschmidt
2006-09-11 1:48 ` Segher Boessenkool
2006-09-11 3:53 ` Benjamin Herrenschmidt
2006-09-11 18:12 ` Jesse Barnes
2006-09-11 1:00 ` Benjamin Herrenschmidt
2006-09-11 18:08 ` Jesse Barnes
2006-09-11 21:32 ` Benjamin Herrenschmidt
2006-09-10 20:01 ` Segher Boessenkool
2006-09-11 13:21 ` David Miller
2006-09-11 14:17 ` Segher Boessenkool
2006-09-12 0:32 ` David Miller
2006-09-12 0:49 ` Benjamin Herrenschmidt
2006-09-12 16:47 ` Segher Boessenkool
2006-09-12 0:54 ` Roland Dreier
2006-09-09 11:16 ` Paul Mackerras
2006-09-09 7:23 ` Benjamin Herrenschmidt
2006-09-09 9:38 ` David Miller
2006-09-09 15:09 ` Alan Cox
2006-09-10 17:19 ` Jesse Barnes
2006-09-10 17:35 ` Michael Buesch
2006-09-10 17:49 ` Linus Torvalds
2006-09-10 18:02 ` Michael Buesch
2006-09-09 15:08 ` Alan Cox
2006-09-09 18:34 ` Auke Kok
2006-09-09 19:10 ` Patrick McFarland
2006-09-09 15:06 ` Alan Cox
-- strict thread matches above, loose matches on Subject: below --
2006-09-11 5:03 Michael Chan
2006-09-11 5:21 ` Benjamin Herrenschmidt
2006-09-12 4:30 Albert Cahalan
2006-09-12 5:30 ` Benjamin Herrenschmidt
2006-09-12 6:04 ` Albert Cahalan
2006-09-12 6:12 ` Benjamin Herrenschmidt
2006-09-12 7:09 ` Albert Cahalan
2006-09-12 7:17 ` Benjamin Herrenschmidt
2006-09-12 7:21 ` Albert Cahalan
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