Hi Leonardo,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on paulus-powerpc/kvm-ppc-next linus/master v5.5 next-20200206]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Leonardo-Bras/Introduces-new-functions-for-tracking-lockless-pagetable-walks/20200207-071035
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: i386-tinyconfig (attached as .config)
compiler: gcc-7 (Debian 7.5.0-3) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   mm/gup.c: In function 'get_user_pages_fast':
>> mm/gup.c:2435:27: error: 'IRQS_ENABLED' undeclared (first use in this function); did you mean 'IS_ENABLED'?
      end_lockless_pgtbl_walk(IRQS_ENABLED);
                              ^~~~~~~~~~~~
                              IS_ENABLED
   mm/gup.c:2435:27: note: each undeclared identifier is reported only once for each function it appears in

vim +2435 mm/gup.c

  2395	
  2396	/**
  2397	 * get_user_pages_fast() - pin user pages in memory
  2398	 * @start:	starting user address
  2399	 * @nr_pages:	number of pages from start to pin
  2400	 * @gup_flags:	flags modifying pin behaviour
  2401	 * @pages:	array that receives pointers to the pages pinned.
  2402	 *		Should be at least nr_pages long.
  2403	 *
  2404	 * Attempt to pin user pages in memory without taking mm->mmap_sem.
  2405	 * If not successful, it will fall back to taking the lock and
  2406	 * calling get_user_pages().
  2407	 *
  2408	 * Returns number of pages pinned. This may be fewer than the number
  2409	 * requested. If nr_pages is 0 or negative, returns 0. If no pages
  2410	 * were pinned, returns -errno.
  2411	 */
  2412	int get_user_pages_fast(unsigned long start, int nr_pages,
  2413				unsigned int gup_flags, struct page **pages)
  2414	{
  2415		unsigned long addr, len, end;
  2416		int nr = 0, ret = 0;
  2417	
  2418		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM)))
  2419			return -EINVAL;
  2420	
  2421		start = untagged_addr(start) & PAGE_MASK;
  2422		addr = start;
  2423		len = (unsigned long) nr_pages << PAGE_SHIFT;
  2424		end = start + len;
  2425	
  2426		if (end <= start)
  2427			return 0;
  2428		if (unlikely(!access_ok((void __user *)start, len)))
  2429			return -EFAULT;
  2430	
  2431		if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) &&
  2432		    gup_fast_permitted(start, end)) {
  2433			begin_lockless_pgtbl_walk();
  2434			gup_pgd_range(addr, end, gup_flags, pages, &nr);
> 2435			end_lockless_pgtbl_walk(IRQS_ENABLED);

---
0-DAY CI Kernel Test Service, Intel Corporation
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