On 03/10/2017 06:42 AM, Ye Xiaolong wrote: > On 03/08, Anshuman Khandual wrote: >> On 02/17/2017 09:00 PM, kbuild test robot wrote: >>> Hi Zi, >>> >>> [auto build test ERROR on linus/master] >>> [also build test ERROR on v4.10-rc8 next-20170217] >>> [if your patch is applied to the wrong git tree, please drop us a note to >>> help improve the system] >>> >>> url: >>> https://github.com/0day-ci/linux/commits/Anshuman-Khandual/Enable-parallel-page-migration/20170217-200523 >>> config: i386-randconfig-a0-02131010 (attached as .config) >>> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 >> Though I dont have the same compiler, I am unable to reproduce this >> build failure exactly. The build fails but for a different symbol. > I think previous "undefined reference to `mt_page_copy'" error is due to > kbuild > bot didn't set CONFIG_MIGRATION (see attached config in original mail) since > it > is a randconfig test.
If CONFIG_MIGRATION is not set then mm/migrate.c never gets compiled and the symbol 'mt_page_copy' is never exported for kernel/sysctl.c based extern variable to use. Sure, will fix it by keeping all the code in kernel/sysctl.c within CONFIG_MIGRATION config. Thanks for pointing it out.