From: Catalin Marinas <catalin.marinas@arm.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Kevin Hilman <khilman@ti.com>, "david@lang.hm" <david@lang.hm>,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
Nicolas Pitre <nico@fluxnic.net>,
Tony Lindgren <tony@atomide.com>,
Catalin Marinas <catalin.marinas@arm.com>,
lkml <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Brown <davidb@codeaurora.org>,
Detlef Vollmann <dv@vollmann.ch>
Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window
Date: Fri, 1 Apr 2011 22:51:19 +0100 [thread overview]
Message-ID: <AANLkTin46Hu7BRNrTYYxHwaE10emUM7VNPWwg9w4r9n6@mail.gmail.com> (raw)
In-Reply-To: <201104012332.24319.arnd@arndb.de>
On Friday, 1 April 2011, Arnd Bergmann <arnd@arndb.de> wrote:
> On Friday 01 April 2011 23:10:04 Kevin Hilman wrote:
>> Arnd Bergmann <arnd@arndb.de> writes:
>>
>> > On Friday 01 April 2011, Detlef Vollmann wrote:
>> >> On 04/01/11 15:54, Arnd Bergmann wrote:
>> >
>> >> > 9. All interesting work is going into a handful of platforms, all of which
>> >> > are ARMv7 based.
>> >> Define interesting.
>> >
>> > The ones that are causing the churn that we're talking about.
>> > Platforms that have been working forever and only need to get
>> > the occasional bug fix are boring, i.e. not the problem.
>>
>> I'm not sure I follow the ARMv7-only thinking either.
>>
>> Picking ARMv7 only would be a good way to avoid part of the problem, but
>> IMO, it doesn't really address the root causes. Part of the ugliness of
>> the platform-specific hackery (and the "churn" to clean some of it up)
>> is precisely due to support for multiple ARM architecture versions, and
>> the various SoCs in a family that use them. For example, linux-omap
>> supports OMAP1 (ARMv5), OMAP2 (ARMv6), OMAP3 (ARMv7) and OMAP4 (ARMv7
>> SMP), and OMAP2/3/4 in a single binary.
>>
>> Also, since we've only very recently got to the point of being able to
>> support ARMv6 + ARMv7 UP & SMP in the same kernel, making a decision now
>> that only ARMv7 is important seems like a step backwards. If the
>> ultimate goal is getting to a point where we have infrastrucure that can
>> be cross-SoC, surely this same infrastrucure should support multiple ARM
>> architecture revisions.
>
> Yes, forget about the ARMv7 part of my proposal, that was not a main point.
>
> If we decide to have a new clean platform variant the way I suggested,
> it would be nice to support all machines in a single kernel binary,
> and at least v6+v7 is a solved problem.
>
> Supporting a second kernel binary up to v5 with the same source is also
> simple, as would be big-endian/little-endian variants, or thumb2/arm variants.
> We might not want to do all combinations from the start though, and I would
> choose ARMv6/v7-thumb2-le simply because that's what Linaro is focusing
> on. The idea is to start with a clearly defined set, but write the code
> in a way that makes it possible to extend in other directions.
Thumb-2 is ARMv7 only. If you want a v6+v7 binary it would need to be
compiled to ARM.
--
Catalin
next prev parent reply other threads:[~2011-04-01 21:51 UTC|newest]
Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 18:30 [GIT PULL] omap changes for v2.6.39 merge window Tony Lindgren
2011-03-18 2:50 ` Linus Torvalds
2011-03-18 7:06 ` Tony Lindgren
2011-03-18 10:15 ` Russell King - ARM Linux
2011-03-18 11:13 ` Uwe Kleine-König
2011-03-30 17:06 ` Arnd Bergmann
2011-03-30 19:21 ` Linus Torvalds
2011-03-30 20:41 ` Nicolas Pitre
2011-03-30 21:02 ` Linus Torvalds
2011-03-30 23:31 ` Nicolas Pitre
2011-03-30 23:59 ` Russell King - ARM Linux
2011-03-31 0:15 ` Tony Lindgren
2011-03-31 0:31 ` Bill Gatliff
2011-03-31 0:39 ` david
2011-03-31 3:17 ` Nicolas Pitre
2011-03-31 3:29 ` Dave Airlie
2011-03-31 4:38 ` Nicolas Pitre
2011-03-31 9:54 ` Alan Cox
2011-03-31 10:50 ` Russell King - ARM Linux
2011-03-31 12:23 ` Jean-Christophe PLAGNIOL-VILLARD
2011-03-31 12:38 ` Catalin Marinas
2011-03-31 13:01 ` Russell King - ARM Linux
2011-03-31 14:55 ` Bill Gatliff
2011-04-01 12:41 ` Arnd Bergmann
2011-03-31 18:12 ` Sam Ravnborg
2011-03-31 18:17 ` Russell King - ARM Linux
2011-03-31 18:34 ` Jesse Barnes
2011-03-31 13:54 ` Thomas Gleixner
2011-03-31 17:22 ` david
2011-03-31 18:08 ` Koen Kooi
2011-03-31 5:05 ` david
2011-03-31 7:15 ` Nicolas Pitre
2011-03-31 8:06 ` Ingo Molnar
2011-03-31 8:30 ` Russell King - ARM Linux
2011-03-31 10:41 ` Ingo Molnar
2011-03-31 13:25 ` Russell King - ARM Linux
2011-03-31 12:04 ` Thomas Gleixner
2011-03-31 14:43 ` Kevin Hilman
2011-03-31 15:01 ` Thomas Gleixner
2011-03-31 15:05 ` Russell King - ARM Linux
2011-03-31 15:45 ` david
2011-03-31 15:23 ` Arnd Bergmann
2011-03-31 16:58 ` Thomas Gleixner
2011-03-31 18:23 ` Nicolas Pitre
2011-03-31 18:55 ` Thomas Gleixner
2011-04-01 11:32 ` Arnd Bergmann
2011-03-31 20:35 ` Kevin Hilman
2011-04-01 11:29 ` Arnd Bergmann
2011-04-01 7:32 ` Tomi Valkeinen
2011-04-01 11:22 ` Arnd Bergmann
2011-04-01 11:55 ` Tomi Valkeinen
2011-04-01 12:07 ` Arnd Bergmann
2011-04-01 12:15 ` Tomi Valkeinen
2011-03-31 16:03 ` david
2011-03-31 16:45 ` Russell King - ARM Linux
2011-03-31 17:17 ` Linus Torvalds
2011-03-31 19:25 ` Nicolas Pitre
2011-03-31 20:05 ` Linus Torvalds
2011-03-31 20:28 ` Linus Torvalds
2011-03-31 22:49 ` Nicolas Pitre
2011-04-01 0:53 ` Mark Brown
2011-04-01 4:50 ` David Brown
2011-04-01 7:45 ` Ingo Molnar
2011-04-01 13:54 ` Arnd Bergmann
[not found] ` <4D95E112.4020400@vollmann.ch>
2011-04-01 14:59 ` Arnd Bergmann
[not found] ` <4D95EF8E.9080902@vollmann.ch>
2011-04-01 15:50 ` Arnd Bergmann
2011-04-01 17:44 ` Russell King - ARM Linux
2011-04-01 19:54 ` Nicolas Pitre
2011-04-01 21:00 ` Uwe Kleine-König
2011-04-01 22:08 ` Arnd Bergmann
2011-04-02 2:24 ` Nicolas Pitre
2011-04-03 15:26 ` Arnd Bergmann
2011-04-03 16:03 ` Russell King - ARM Linux
2011-04-04 0:59 ` Arnd Bergmann
2011-04-04 8:26 ` Marc Zyngier
2011-04-04 11:03 ` Catalin Marinas
2011-04-04 11:21 ` Russell King - ARM Linux
2011-04-04 13:24 ` Marc Zyngier
2011-04-04 13:31 ` Russell King - ARM Linux
2011-04-04 13:57 ` Marc Zyngier
2011-04-04 20:08 ` Linus Walleij
2011-04-05 6:40 ` Santosh Shilimkar
2011-04-05 7:45 ` Russell King - ARM Linux
2011-04-05 14:15 ` Catalin Marinas
2011-04-05 22:16 ` Linus Walleij
2011-04-06 6:43 ` Santosh Shilimkar
2011-04-05 22:22 ` Linus Walleij
2011-04-06 6:41 ` Santosh Shilimkar
2011-04-05 7:30 ` Marc Zyngier
2011-05-26 13:38 ` Pavel Machek
2011-04-02 2:59 ` Mark Brown
2011-04-04 5:16 ` Jean-Christophe PLAGNIOL-VILLARD
2011-04-04 9:27 ` Nicolas Ferre
2011-04-01 21:10 ` Kevin Hilman
2011-04-01 21:32 ` Arnd Bergmann
2011-04-01 21:51 ` Catalin Marinas [this message]
2011-04-03 22:18 ` Benjamin Herrenschmidt
2011-04-04 0:14 ` Arnd Bergmann
2011-04-04 2:49 ` Nicolas Pitre
2011-04-01 15:27 ` Will Deacon
2011-04-01 15:55 ` Arnd Bergmann
2011-04-01 16:39 ` Linus Torvalds
2011-04-03 22:26 ` Benjamin Herrenschmidt
2011-04-05 23:19 ` Linus Walleij
2011-04-06 8:41 ` Catalin Marinas
2011-04-07 1:44 ` Arnd Bergmann
2011-04-01 20:19 ` Nicolas Pitre
2011-04-02 4:38 ` Richard Cochran
2011-04-02 3:27 ` Mark Brown
2011-04-06 6:11 ` Barry Song
2011-04-06 7:31 ` Bryan Wu
2011-03-31 21:40 ` Thomas Gleixner
2011-03-31 17:56 ` Nicolas Pitre
2011-03-31 18:34 ` Thomas Gleixner
2011-03-31 19:02 ` Linus Torvalds
2011-03-31 8:09 ` Russell King - ARM Linux
2011-03-31 10:49 ` Felipe Balbi
2011-03-31 18:00 ` Alexander Holler
2011-03-31 5:45 ` Geert Uytterhoeven
2011-03-31 7:21 ` Nicolas Pitre
2011-03-30 22:08 ` Tony Lindgren
2011-03-30 21:10 ` Thomas Gleixner
2011-03-30 21:54 ` Tony Lindgren
2011-03-30 22:25 ` Thomas Gleixner
2011-03-30 22:45 ` Tony Lindgren
2011-03-30 22:56 ` Thomas Gleixner
2011-04-01 1:42 ` Mark Brown
2011-03-30 22:38 ` Paul E. McKenney
2011-03-30 22:47 ` Tony Lindgren
2011-03-30 23:13 ` Paul E. McKenney
2011-03-30 23:14 ` Thomas Gleixner
2011-03-30 23:28 ` Tony Lindgren
2011-03-31 11:00 ` Artem Bityutskiy
2011-03-31 13:54 ` Arnd Bergmann
2011-03-30 21:44 ` Tony Lindgren
2011-03-30 22:20 ` Linus Torvalds
2011-03-30 22:39 ` Tony Lindgren
2011-03-31 0:15 ` Russell King - ARM Linux
2011-03-31 0:55 ` Linus Torvalds
2011-03-31 1:15 ` Bill Gatliff
2011-03-31 1:37 ` Linus Torvalds
2011-03-31 1:44 ` Bill Gatliff
2011-03-31 1:56 ` Linus Torvalds
2011-03-31 2:20 ` Bill Gatliff
2011-03-31 3:24 ` Linus Torvalds
2011-03-31 6:42 ` Olof Johansson
2011-03-31 6:56 ` David Brown
2011-03-31 11:27 ` Felipe Balbi
2011-03-31 13:39 ` Thomas Gleixner
2011-03-31 4:09 ` Nicolas Pitre
2011-03-31 10:11 ` Thomas Gleixner
2011-03-30 21:07 ` Russell King - ARM Linux
2011-03-30 22:14 ` Tony Lindgren
2011-04-01 1:17 ` Mark Brown
2011-04-01 14:17 ` Arnd Bergmann
2011-03-18 3:02 ` Linus Torvalds
2011-03-18 7:09 ` Tony Lindgren
2011-03-18 8:06 ` Ohad Ben-Cohen
2011-03-18 23:43 ` Tony Lindgren
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AANLkTin46Hu7BRNrTYYxHwaE10emUM7VNPWwg9w4r9n6@mail.gmail.com \
--to=catalin.marinas@arm.com \
--cc=arnd@arndb.de \
--cc=david@lang.hm \
--cc=davidb@codeaurora.org \
--cc=dv@vollmann.ch \
--cc=hpa@zytor.com \
--cc=khilman@ti.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=mingo@elte.hu \
--cc=nico@fluxnic.net \
--cc=tglx@linutronix.de \
--cc=tony@atomide.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).