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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Arnd Bergmann <arnd@arndb.de>,
	Matthew Wilcox <willy@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Segher Boessenkool <segher@kernel.crashing.org>,
	Joe Perches <joe@perches.com>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	Paul Mackerras <paulus@samba.org>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Will Deacon <will@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] Raise the minimum GCC version to 5.2
Date: Tue, 4 May 2021 08:33:28 +0200	[thread overview]
Message-ID: <6615493a-252c-ee40-a9fa-27cf5ad8922b@csgroup.eu> (raw)
In-Reply-To: <YJDb9uLQBgoy94Ub@ada-deb-carambola.ifak-system.com>



Le 04/05/2021 à 07:30, Alexander Dahl a écrit :
> Hello Arnd,
> 
> Am Mon, May 03, 2021 at 11:25:21AM +0200 schrieb Arnd Bergmann:
>> On Mon, May 3, 2021 at 9:35 AM Alexander Dahl <ada@thorsis.com> wrote:
>>>
>>> Desktops and servers are all nice, however I just want to make you
>>> aware, there are embedded users forced to stick to older cross
>>> toolchains for different reasons as well, e.g. in industrial
>>> environment. :-)
>>>
>>> This is no show stopper for us, I just wanted to let you be aware.
>>
>> Can you be more specific about what scenarios you are thinking of,
>> what the motivations are for using an old compiler with a new kernel
>> on embedded systems, and what you think a realistic maximum
>> time would be between compiler updates?
> 
> One reason might be certification. For certain industrial applications
> like support for complex field bus protocols, you need to get your
> devices tested by an external partner running extensive test suites.
> This is time consuming and expensive.
> 
> Changing the toolchain of your system then, would be a massive change
> which would require recertification, while you could argue just
> updating a single component like the kernel and building everything
> again, does not require the whole testing process again.

Not sure to follow you.

Our company provides systems for Air Trafic Control, so we have the same kind of assurance quality 
process, but then I can't understand why you would need to upgrade your kernel at all.

Today our system is based on GCC 5 and Kernel 4.14. At the time being we are using GCC 5.5 (Latest 
GCC 5) and kernel 4.14.232 (Latest 4.14.y). Kernel 4.14 is maintained until 2024.

The day we do an upgrade, we upgrade everything including the tool chain then we go for another 6 
years without major changes/re-qualification, because we can't afford a new qualitication every now 
and then.


So really, I can't see your approach.

Christophe

WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Arnd Bergmann <arnd@arndb.de>,
	Matthew Wilcox <willy@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Segher Boessenkool <segher@kernel.crashing.org>,
	Joe Perches <joe@perches.com>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	Paul Mackerras <paulus@samba.org>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Will Deacon <will@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] Raise the minimum GCC version to 5.2
Date: Tue, 4 May 2021 08:33:28 +0200	[thread overview]
Message-ID: <6615493a-252c-ee40-a9fa-27cf5ad8922b@csgroup.eu> (raw)
In-Reply-To: <YJDb9uLQBgoy94Ub@ada-deb-carambola.ifak-system.com>



Le 04/05/2021 à 07:30, Alexander Dahl a écrit :
> Hello Arnd,
> 
> Am Mon, May 03, 2021 at 11:25:21AM +0200 schrieb Arnd Bergmann:
>> On Mon, May 3, 2021 at 9:35 AM Alexander Dahl <ada@thorsis.com> wrote:
>>>
>>> Desktops and servers are all nice, however I just want to make you
>>> aware, there are embedded users forced to stick to older cross
>>> toolchains for different reasons as well, e.g. in industrial
>>> environment. :-)
>>>
>>> This is no show stopper for us, I just wanted to let you be aware.
>>
>> Can you be more specific about what scenarios you are thinking of,
>> what the motivations are for using an old compiler with a new kernel
>> on embedded systems, and what you think a realistic maximum
>> time would be between compiler updates?
> 
> One reason might be certification. For certain industrial applications
> like support for complex field bus protocols, you need to get your
> devices tested by an external partner running extensive test suites.
> This is time consuming and expensive.
> 
> Changing the toolchain of your system then, would be a massive change
> which would require recertification, while you could argue just
> updating a single component like the kernel and building everything
> again, does not require the whole testing process again.

Not sure to follow you.

Our company provides systems for Air Trafic Control, so we have the same kind of assurance quality 
process, but then I can't understand why you would need to upgrade your kernel at all.

Today our system is based on GCC 5 and Kernel 4.14. At the time being we are using GCC 5.5 (Latest 
GCC 5) and kernel 4.14.232 (Latest 4.14.y). Kernel 4.14 is maintained until 2024.

The day we do an upgrade, we upgrade everything including the tool chain then we go for another 6 
years without major changes/re-qualification, because we can't afford a new qualitication every now 
and then.


So really, I can't see your approach.

Christophe

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Arnd Bergmann <arnd@arndb.de>,
	Matthew Wilcox <willy@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Segher Boessenkool <segher@kernel.crashing.org>,
	Joe Perches <joe@perches.com>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	Paul Mackerras <paulus@samba.org>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Will Deacon <will@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] Raise the minimum GCC version to 5.2
Date: Tue, 4 May 2021 08:33:28 +0200	[thread overview]
Message-ID: <6615493a-252c-ee40-a9fa-27cf5ad8922b@csgroup.eu> (raw)
In-Reply-To: <YJDb9uLQBgoy94Ub@ada-deb-carambola.ifak-system.com>



Le 04/05/2021 à 07:30, Alexander Dahl a écrit :
> Hello Arnd,
> 
> Am Mon, May 03, 2021 at 11:25:21AM +0200 schrieb Arnd Bergmann:
>> On Mon, May 3, 2021 at 9:35 AM Alexander Dahl <ada@thorsis.com> wrote:
>>>
>>> Desktops and servers are all nice, however I just want to make you
>>> aware, there are embedded users forced to stick to older cross
>>> toolchains for different reasons as well, e.g. in industrial
>>> environment. :-)
>>>
>>> This is no show stopper for us, I just wanted to let you be aware.
>>
>> Can you be more specific about what scenarios you are thinking of,
>> what the motivations are for using an old compiler with a new kernel
>> on embedded systems, and what you think a realistic maximum
>> time would be between compiler updates?
> 
> One reason might be certification. For certain industrial applications
> like support for complex field bus protocols, you need to get your
> devices tested by an external partner running extensive test suites.
> This is time consuming and expensive.
> 
> Changing the toolchain of your system then, would be a massive change
> which would require recertification, while you could argue just
> updating a single component like the kernel and building everything
> again, does not require the whole testing process again.

Not sure to follow you.

Our company provides systems for Air Trafic Control, so we have the same kind of assurance quality 
process, but then I can't understand why you would need to upgrade your kernel at all.

Today our system is based on GCC 5 and Kernel 4.14. At the time being we are using GCC 5.5 (Latest 
GCC 5) and kernel 4.14.232 (Latest 4.14.y). Kernel 4.14 is maintained until 2024.

The day we do an upgrade, we upgrade everything including the tool chain then we go for another 6 
years without major changes/re-qualification, because we can't afford a new qualitication every now 
and then.


So really, I can't see your approach.

Christophe

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-05-04  6:33 UTC|newest]

Thread overview: 146+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-01 15:15 [PATCH] Raise the minimum GCC version to 5.2 Masahiro Yamada
2021-05-01 15:15 ` Masahiro Yamada
2021-05-01 15:15 ` Masahiro Yamada
2021-05-01 15:15 ` Masahiro Yamada
2021-05-01 15:52 ` Miguel Ojeda
2021-05-01 15:52   ` Miguel Ojeda
2021-05-01 15:52   ` Miguel Ojeda
2021-05-01 15:52   ` Miguel Ojeda
2021-05-01 17:38   ` Christophe Leroy
2021-05-01 17:38     ` Christophe Leroy
2021-05-01 17:38     ` Christophe Leroy
2021-05-01 17:38     ` Christophe Leroy
2021-05-02  2:41   ` Joe Perches
2021-05-02  2:41     ` Joe Perches
2021-05-02  2:41     ` Joe Perches
2021-05-02  2:41     ` Joe Perches
2021-05-02 18:30     ` Segher Boessenkool
2021-05-02 18:30       ` Segher Boessenkool
2021-05-02 18:30       ` Segher Boessenkool
2021-05-02 18:30       ` Segher Boessenkool
2021-05-02 20:00       ` Joe Perches
2021-05-02 20:00         ` Joe Perches
2021-05-02 20:00         ` Joe Perches
2021-05-02 20:00         ` Joe Perches
2021-05-02 20:32         ` Segher Boessenkool
2021-05-02 20:32           ` Segher Boessenkool
2021-05-02 20:32           ` Segher Boessenkool
2021-05-02 20:32           ` Segher Boessenkool
2021-05-02 21:05           ` Ali Kaasinen
2021-05-02 21:05             ` Ali Kaasinen
2021-05-02 21:05             ` Ali Kaasinen
2021-05-02 21:05             ` Ali Kaasinen
2021-05-02 21:08           ` Linus Torvalds
2021-05-02 21:08             ` Linus Torvalds
2021-05-02 21:08             ` Linus Torvalds
2021-05-02 21:08             ` Linus Torvalds
2021-05-02 22:30             ` Matthew Wilcox
2021-05-02 22:30               ` Matthew Wilcox
2021-05-02 22:30               ` Matthew Wilcox
2021-05-02 22:30               ` Matthew Wilcox
2021-05-03  7:34               ` Alexander Dahl
2021-05-03  7:34                 ` Alexander Dahl
2021-05-03  7:34                 ` Alexander Dahl
2021-05-03  7:34                 ` Alexander Dahl
2021-05-03  8:54                 ` Joe Perches
2021-05-03  8:54                   ` Joe Perches
2021-05-03  8:54                   ` Joe Perches
2021-05-03  8:54                   ` Joe Perches
2021-05-03  9:25                 ` Arnd Bergmann
2021-05-03  9:25                   ` Arnd Bergmann
2021-05-03  9:25                   ` Arnd Bergmann
2021-05-03  9:25                   ` Arnd Bergmann
2021-05-03 12:20                   ` David Laight
2021-05-03 12:20                     ` David Laight
2021-05-03 12:20                     ` David Laight
2021-05-03 13:10                     ` Miguel Ojeda
2021-05-03 13:10                       ` Miguel Ojeda
2021-05-03 13:10                       ` Miguel Ojeda
2021-05-03 13:10                       ` Miguel Ojeda
2021-05-04  5:30                   ` Alexander Dahl
2021-05-04  5:30                     ` Alexander Dahl
2021-05-04  5:30                     ` Alexander Dahl
2021-05-04  5:30                     ` Alexander Dahl
2021-05-04  6:33                     ` Christophe Leroy [this message]
2021-05-04  6:33                       ` Christophe Leroy
2021-05-04  6:33                       ` Christophe Leroy
2021-05-04 12:07                     ` Arnd Bergmann
2021-05-04 12:07                       ` Arnd Bergmann
2021-05-04 12:07                       ` Arnd Bergmann
2021-05-04 12:07                       ` Arnd Bergmann
2021-05-04 13:25                   ` Andy Shevchenko
2021-05-04 13:25                     ` Andy Shevchenko
2021-05-04 13:25                     ` Andy Shevchenko
2021-05-04 13:25                     ` Andy Shevchenko
2021-05-03 11:35               ` Arnd Bergmann
2021-05-03 11:35                 ` Arnd Bergmann
2021-05-03 11:35                 ` Arnd Bergmann
2021-05-03 11:35                 ` Arnd Bergmann
2021-05-03  9:49             ` Kirill A. Shutemov
2021-05-03  9:49               ` Kirill A. Shutemov
2021-05-03  9:49               ` Kirill A. Shutemov
2021-05-03  9:49               ` Kirill A. Shutemov
2021-05-02 21:23           ` Joe Perches
2021-05-02 21:23             ` Joe Perches
2021-05-02 21:23             ` Joe Perches
2021-05-02 21:23             ` Joe Perches
2021-05-03  0:44             ` Segher Boessenkool
2021-05-03  0:44               ` Segher Boessenkool
2021-05-03  0:44               ` Segher Boessenkool
2021-05-03  0:44               ` Segher Boessenkool
2021-05-03  9:57               ` Arnd Bergmann
2021-05-03  9:57                 ` Arnd Bergmann
2021-05-03  9:57                 ` Arnd Bergmann
2021-05-03  9:57                 ` Arnd Bergmann
2021-05-04  7:56     ` Ben Dooks
2021-05-04  7:56       ` Ben Dooks
2021-05-04  7:56       ` Ben Dooks
2021-05-04  7:56       ` Ben Dooks
2021-05-04  8:38       ` Miguel Ojeda
2021-05-04  8:38         ` Miguel Ojeda
2021-05-04  8:38         ` Miguel Ojeda
2021-05-04  8:38         ` Miguel Ojeda
2021-05-04  9:22         ` Michal Suchánek
2021-05-04  9:22           ` Michal Suchánek
2021-05-04  9:22           ` Michal Suchánek
2021-05-04  9:22           ` Michal Suchánek
2021-05-04 12:09           ` Miguel Ojeda
2021-05-04 12:09             ` Miguel Ojeda
2021-05-04 12:09             ` Miguel Ojeda
2021-05-04 12:09             ` Miguel Ojeda
2021-05-04 12:17             ` Michal Suchánek
2021-05-04 12:17               ` Michal Suchánek
2021-05-04 12:17               ` Michal Suchánek
2021-05-04 12:17               ` Michal Suchánek
2021-05-04 12:26               ` Christophe Leroy
2021-05-04 12:26                 ` Christophe Leroy
2021-05-04 12:26                 ` Christophe Leroy
2021-05-04 12:26                 ` Christophe Leroy
2021-05-02 18:37 ` Segher Boessenkool
2021-05-02 18:37   ` Segher Boessenkool
2021-05-02 18:37   ` Segher Boessenkool
2021-05-02 18:37   ` Segher Boessenkool
2021-05-03  6:16 ` Christophe Leroy
2021-05-03  6:16   ` Christophe Leroy
2021-05-03  6:16   ` Christophe Leroy
2021-05-03  6:16   ` Christophe Leroy
2021-05-04  2:13   ` Masahiro Yamada
2021-05-04  2:13     ` Masahiro Yamada
2021-05-04  2:13     ` Masahiro Yamada
2021-05-04  2:13     ` Masahiro Yamada
2021-05-04 13:18   ` Andy Shevchenko
2021-05-04 13:18     ` Andy Shevchenko
2021-05-04 13:18     ` Andy Shevchenko
2021-05-04 13:18     ` Andy Shevchenko
2021-05-03 12:27 ` David Sterba
2021-05-03 12:27   ` David Sterba
2021-05-03 12:27   ` David Sterba
2021-05-03 12:27   ` David Sterba
2021-05-15  7:14 ` Pavel Machek
2021-05-15  7:14   ` Pavel Machek
2021-05-15  7:14   ` Pavel Machek
2021-05-15  7:14   ` Pavel Machek
2021-05-15  7:27   ` Joe Perches
2021-05-15  7:27     ` Joe Perches
2021-05-15  7:27     ` Joe Perches
2021-05-15  7:27     ` Joe Perches

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