[linux-next:master 4318/4736] arch/x86/mm/init.c:1057:15: warning: no previous prototype for 'arch_max_swapfile_size'

[linux-next:master 4318/4736] arch/x86/mm/init.c:1057:15: warning: no previous prototype for 'arch_max_swapfile_size'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   e47eb90a0a9ae20b82635b9b99a8d0979b757ad8
commit: c21e4d92cbb920b50a809409bc56c6ca4f09e7bf [4318/4736] mm/swap: cache maximum swapfile size when init swap
config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20220903/202209030759.1ODqXm2p-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c21e4d92cbb920b50a809409bc56c6ca4f09e7bf
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout c21e4d92cbb920b50a809409bc56c6ca4f09e7bf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/mm/ mm/

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

All warnings (new ones prefixed by >>):

>> arch/x86/mm/init.c:1057:15: warning: no previous prototype for 'arch_max_swapfile_size' [-Wmissing-prototypes]
    1057 | unsigned long arch_max_swapfile_size(void)
         |               ^~~~~~~~~~~~~~~~~~~~~~
--
>> mm/swapfile.c:2820:22: warning: no previous prototype for 'arch_max_swapfile_size' [-Wmissing-prototypes]
    2820 | __weak unsigned long arch_max_swapfile_size(void)
         |                      ^~~~~~~~~~~~~~~~~~~~~~


vim +/arch_max_swapfile_size +1057 arch/x86/mm/init.c

  1055	
  1056	#ifdef CONFIG_SWAP
> 1057	unsigned long arch_max_swapfile_size(void)

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [linux-next:master 4318/4736] arch/x86/mm/init.c:1057:15: warning: no previous prototype for 'arch_max_swapfile_size'

[Peter Xu]

[-- Attachment #1: Type: text/plain, Size: 2123 bytes --]

On Sat, Sep 03, 2022 at 07:32:02AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   e47eb90a0a9ae20b82635b9b99a8d0979b757ad8
> commit: c21e4d92cbb920b50a809409bc56c6ca4f09e7bf [4318/4736] mm/swap: cache maximum swapfile size when init swap
> config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20220903/202209030759.1ODqXm2p-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
> reproduce (this is a W=1 build):
>         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c21e4d92cbb920b50a809409bc56c6ca4f09e7bf
>         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>         git fetch --no-tags linux-next master
>         git checkout c21e4d92cbb920b50a809409bc56c6ca4f09e7bf
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/mm/ mm/
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> arch/x86/mm/init.c:1057:15: warning: no previous prototype for 'arch_max_swapfile_size' [-Wmissing-prototypes]
>     1057 | unsigned long arch_max_swapfile_size(void)
>          |               ^~~~~~~~~~~~~~~~~~~~~~
> --
> >> mm/swapfile.c:2820:22: warning: no previous prototype for 'arch_max_swapfile_size' [-Wmissing-prototypes]
>     2820 | __weak unsigned long arch_max_swapfile_size(void)
>          |                      ^~~~~~~~~~~~~~~~~~~~~~
> 
> 
> vim +/arch_max_swapfile_size +1057 arch/x86/mm/init.c
> 
>   1055	
>   1056	#ifdef CONFIG_SWAP
> > 1057	unsigned long arch_max_swapfile_size(void)
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp

Hi, Andrew,

The oneliner patch fixes the issue for me, which is attached.  The patch to
squash in is within the subject after "fixup: " (ff516092aa69 ("mm/swap:
cache maximum swapfile size when init swap", 2022-09-02)).

Thanks,

-- 
Peter Xu

[-- Attachment #2: 0001-fixup-mm-swap-cache-maximum-swapfile-size-when-init-.patch --]
[-- Type: text/plain, Size: 970 bytes --]

From 99ce98e66d67ecadc6a73791aa425d76155a9f59 Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx@redhat.com>
Date: Sun, 4 Sep 2022 13:31:38 -0400
Subject: [PATCH] fixup! mm/swap: cache maximum swapfile size when init swap
Content-type: text/plain

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/linux/swapfile.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h
index 75fc069594a5..29182dfc0cc7 100644
--- a/include/linux/swapfile.h
+++ b/include/linux/swapfile.h
@@ -10,6 +10,7 @@ extern spinlock_t swap_lock;
 extern struct plist_head swap_active_head;
 extern struct swap_info_struct *swap_info[];
 extern unsigned long generic_max_swapfile_size(void);
+extern unsigned long arch_max_swapfile_size(void);
 /* Maximum swapfile size supported for the arch (not inclusive). */
 extern unsigned long swapfile_maximum_size;
 /* Whether swap migration entry supports storing A/D bits for the arch */
-- 
2.32.0