[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Parallel building of Linux Kernel is broken

From: Masahiro Yamada
Subject: Parallel building of Linux Kernel is broken
Date: Thu, 12 Jul 2018 10:26:48 +0900

Hello GNU Make folks,

I am a Linux kernel developer.

I think the following commit broke
the parallel building of Linux kernel.

commit 2b8e3bb23f96c2458818f011593557d3353dade3
Author: Paul Smith <address@hidden>
Date:   Mon Jan 2 14:08:54 2017 -0500

    Clean up close-on-exec, particularly with jobserver pipes.

How to reproduce the problem

You can get the Linux kernel source code by

$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
$ git checkout v4.17

At the top of the Linux kernel source tree, run

$ make -j8 defconfig all

This worked fine with GNU Make prior to that commit.

If you use GNU Make with that commit,
'jobserver unavailable: using -j1.  Add '+' to parent make rule'
is displayed, then the whole build process of Linux kernel
is serialized.

$ make -j8 defconfig all
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  YACC    scripts/kconfig/zconf.tab.c
  LEX     scripts/kconfig/zconf.lex.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
*** Default configuration is based on 'x86_64_defconfig'
# configuration written to .config
scripts/kconfig/conf  --syncconfig Kconfig
make[1]: warning: jobserver unavailable: using -j1.  Add '+' to parent
make rule.
  SYSTBL  arch/x86/include/generated/asm/syscalls_32.h

The commit subject says 'Clean up', but
I think this is accidental breakage.

Any clue?

Best Regards
Masahiro Yamada

reply via email to

[Prev in Thread] Current Thread [Next in Thread]