From: Nadav Amit <namit@vmware.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
X86 ML <x86@kernel.org>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Logan Gunthorpe <logang@deltatee.com>
Subject: Re: [PATCH 1/2] Makefile: Fix distcc compilation with x86 macros
Date: Tue, 13 Nov 2018 18:34:39 +0000 [thread overview]
Message-ID: <48577A3F-0F76-4CCA-A959-965344D7259F@vmware.com> (raw)
In-Reply-To: <40E4E1B4-EF5F-43A1-B42C-C4CF6349FC62@vmware.com>
From: Nadav Amit
Sent: November 13, 2018 at 5:55:34 PM GMT
> To: Ingo Molnar <mingo@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>, Masahiro Yamada <yamada.masahiro@socionext.com>, Michal Marek <michal.lkml@markovi.net>, Thomas Gleixner <tglx@linutronix.de>, Borislav Petkov <bp@alien8.de>, H. Peter Anvin <hpa@zytor.com>, X86 ML <x86@kernel.org>, Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, Logan Gunthorpe <logang@deltatee.com>
> Subject: Re: [PATCH 1/2] Makefile: Fix distcc compilation with x86 macros
>
>
> From: Ingo Molnar
> Sent: November 13, 2018 at 11:30:00 AM GMT
>> To: Nadav Amit <namit@vmware.com>
>> Cc: Ingo Molnar <mingo@redhat.com>, Masahiro Yamada <yamada.masahiro@socionext.com>, Michal Marek <michal.lkml@markovi.net>, Thomas Gleixner <tglx@linutronix.de>, Borislav Petkov <bp@alien8.de>, H. Peter Anvin <hpa@zytor.com>, x86@kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH 1/2] Makefile: Fix distcc compilation with x86 macros
>>
>>
>>
>> * Nadav Amit <namit@vmware.com> wrote:
>>
>>> Introducing the use of asm macros in c-code broke distcc, since it only
>>> sends the preprocessed source file. The solution is to break the
>>> compilation into two separate phases of compilation and assembly, and
>>> between the two concatanate the assembly macros and the compiled (yet
>>
>> s/concatenate
>>
>>> not assembled) source file. Since this is less efficient, this
>>> compilation mode is only used when make is called with the "DISTCC=y"
>>> parameter.
>>>
>>> Note that the assembly stage should also be distributed, if distcc is
>>> configured using "CFLAGS=-DENABLE_REMOTE_ASSEMBLE".
>>
>> It's a bit sad that we regressed distcc performance …
>
> I don’t know what the actual impact is, but Logan, who reported the bug says
> there is an alternative solution for when distcc-pump is used (which
> presumably would have ~zero performance degradation). distcc is really
> fragile IMHO - it’s enough that it finds what looks like two source files in
> the compiler command arguments for it to fall back to local compilation.
>
> [ In this regard, the distcc-pump solution would *not* work if distcc is
> built with support for distributed assembly, since it will consider the .s
> file as a second source file. ]
>
>>> +# If distcc is used, then when an assembly macro files is needed, the
>>> +# compilation stage and the assembly stage need to be separated. Providing
>>> +# "DISTCC=y" option enables the separate compilation and assembly.
>>
>> Let's fix the various typos:
>>
>>> +# If distcc is used, and when assembly macro files are needed, the
>>> +# compilation stage and the assembly stage needs to be separated.
>>> +# Providing the "DISTCC=y" option enables separate compilation and
>>> +# assembly.
>
> That’s grammar, not typos ;-)
>
> Sorry for that - I will fix it an send v2 (as well as the whitespace noise).
Just one question before I send v2, since I have second thoughts. Does it
make sense to require the “DISTCC” make parameter, or should it be set in
the Kconfig? It can be detected automatically, the same way gcc/clang are
detected or manually through a config option.
next prev parent reply other threads:[~2018-11-13 18:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 15:02 [PATCH 0/2] x86: Asm macros fixes Nadav Amit
2018-11-12 15:02 ` [PATCH 1/2] Makefile: Fix distcc compilation with x86 macros Nadav Amit
2018-11-13 11:30 ` Ingo Molnar
2018-11-13 17:55 ` Nadav Amit
2018-11-13 18:34 ` Nadav Amit [this message]
2018-11-14 7:29 ` Logan Gunthorpe
2018-11-14 17:46 ` Nadav Amit
2018-11-15 1:19 ` Logan Gunthorpe
2018-11-15 1:57 ` Nadav Amit
2018-11-15 2:00 ` Logan Gunthorpe
2018-11-28 23:09 ` Logan Gunthorpe
2018-11-29 0:38 ` Nadav Amit
2018-11-29 0:49 ` Logan Gunthorpe
2018-11-29 1:31 ` Nadav Amit
2018-11-29 16:43 ` Logan Gunthorpe
2018-12-01 6:29 ` Nadav Amit
2018-11-12 15:02 ` [PATCH 2/2] x86: set a dependency on macros.S Nadav Amit
2018-11-13 11:30 ` Ingo Molnar
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=48577A3F-0F76-4CCA-A959-965344D7259F@vmware.com \
--to=namit@vmware.com \
--cc=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=logang@deltatee.com \
--cc=michal.lkml@markovi.net \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=yamada.masahiro@socionext.com \
/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).