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 17:55:36 +0000 [thread overview]
Message-ID: <40E4E1B4-EF5F-43A1-B42C-C4CF6349FC62@vmware.com> (raw)
In-Reply-To: <20181113113000.GB4788@gmail.com>
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).
Regards,
Nadav
next prev parent reply other threads:[~2018-11-13 17:55 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 [this message]
2018-11-13 18:34 ` Nadav Amit
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
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