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

[Thomas Gleixner]

On Sun, 12 Feb 2017, Hoeun Ryu wrote:
> 
> > On Feb 12, 2017, at 5:19 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> 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?

Sigh. Yes.