Re: [PATCH v5] fork: free vmapped stacks in cache when cpus are offline

[Hoeun Ryu <hoeun.ryu@gmail.com>]

> On Feb 12, 2017, at 5:19 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> 
>> On Sat, 11 Feb 2017, kbuild test robot wrote:
>> 
>> Hi Hoeun,
>> 
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v4.10-rc7 next-20170210]
>> [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/Hoeun-Ryu/fork-free-vmapped-stacks-in-cache-when-cpus-are-offline/20170211-183401
>> config: ia64-allmodconfig (attached as .config)
>> compiler: ia64-linux-gcc (GCC) 6.2.0
>> reproduce:
>>        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>>        chmod +x ~/bin/make.cross
>>        # save the attached .config to linux build tree
>>        make.cross ARCH=ia64 
>> 
>> All errors (new ones prefixed by >>):
>> 
>>   kernel/fork.c: In function 'fork_init':
>>>> kernel/fork.c:483:2: error: implicit declaration of function 'vm_stack_cache_init' [-Werror=implicit-function-declaration]
>>     vm_stack_cache_init();
>>     ^~~~~~~~~~~~~~~~~~~
> 
> Right. This needs to move to a different place as that part is nested inside
> 
> #ifndef CONFIG_ARCH_THREAD_STACK_ALLOCATOR
> 
> That's an horrible ifdef maze in that file.
> 

I think we should rollback to v4. Do you agree?

> Thanks,
> 
>    tglx