From: Nicolas Pitre <nico@fluxnic.net>
To: david@lang.hm
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
Ingo Molnar <mingo@elte.hu>,
Linus Torvalds <torvalds@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>, Tony Lindgren <tony@atomide.com>,
David Brown <davidb@codeaurora.org>,
lkml <linux-kernel@vger.kernel.org>,
linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window
Date: Thu, 31 Mar 2011 13:56:12 -0400 (EDT) [thread overview]
Message-ID: <alpine.LFD.2.00.1103311218240.28032@xanadu.home> (raw)
In-Reply-To: <alpine.DEB.2.00.1103310855450.29543@asgard.lang.hm>
On Thu, 31 Mar 2011, david@lang.hm wrote:
> I think that part of the issue is that when Linus points out a problem, the
> response isn't "we agree and are working on it, here's what we are doing",
> instead it seems to be mostly "there is no problem, this is just because there
> is so much variation in ARM"
The problem is two-fold:
1) - "ARM hardware manufacturers are morons"...
- ARM vendors "do things differently just to be difficult"...
- "the crazy arm fragmentation"...
Translate this into whatever ways you like. The fact is that ARM
is quite popular as a CPU core but there is very little in terms of
standardization around that CPU core. *OBVIOUSLY* this is a problem.
But there is _nothing_ we can do about that besides the current
moaning and the hope that those vendors will hear us and stop trying
to be different from their competitors. Apparently that won't happen
in the near future, so we can either sit on our arses proclaiming
repeatedly that this is a problem until those hardware vendors put
their acts together, or we find ways to deal with it somehow.
2) Because of (1) we do end up being floded by SOC specific support code
with an unprecedented scale. Here's the stat:
$ git diff --shortstat v2.6.38..v2.6.39-rc1 arch/arm/
1319 files changed, 61303 insertions(+), 33780 deletions(-)
$ git diff --shortstat v2.6.38..v2.6.39-rc1 arch/x86/
241 files changed, 6508 insertions(+), 4326 deletions(-)
That's ten (10) times more lines added in the ARM directory than in
the X86 directory. Is this a sudden burst or a tendency?
$ git diff --shortstat v2.6.37..v2.6.38 arch/arm/
1257 files changed, 72412 insertions(+), 29361 deletions(-)
$ git diff --shortstat v2.6.37..v2.6.38 arch/x86/
216 files changed, 10021 insertions(+), 5016 deletions(-)
$ git diff --shortstat v2.6.36..v2.6.37 arch/arm/
1314 files changed, 55072 insertions(+), 17620 deletions(-)
$ git diff --shortstat v2.6.36..v2.6.37 arch/x86/
299 files changed, 16130 insertions(+), 12800 deletions(-)
$ git diff --shortstat v2.6.35..v2.6.36 arch/arm
1041 files changed, 53428 insertions(+), 25722 deletions(-)
$ git diff --shortstat v2.6.35..v2.6.36 arch/x86/
231 files changed, 7216 insertions(+), 8028 deletions(-)
So that appears to be quite "normal" to see ARM vendors together
producing many times the level of activities compared to X86.
So... Is there missed opportunity for better code reuse here? Most
probably. Is all that code the result of misabstracted and duplicated
code? Certainly not. Let's just presume that half of that code is
genuine crap and the other half is simply the result of new hardware for
which there is no existing model to fit it in. Even then, do we have 5
times the reviewer bandwidth to properly review all that code compared
to X86? Absolutely not, not even close.
If prominent people looking at this from the side line continue bashing
at those who are both feet in the mud trying to contain the flood rather
than actually helping then nothing will change. Instead this only
creates despair and the splashed people may simply decide to throw in
the towel, at which point things will collapse for real. In reality,
the system has been going as it is for quite a while and with more or
less the same level of intensity. And the fact is that _users_ of the
ARM kernel are not complaining. Things are far from being perfect, but
so far things have been "good enough" for the majority of the people
involved, and improvements are constantly being worked on with the men
power available.
Nicolas
next prev parent reply other threads:[~2011-03-31 17:56 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
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 [this message]
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
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