[mel:mm-reclaimcongest-v1r4 1/5] mm/vmscan.c:1015:14: error: variable 'ret' set but not used

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-reclaimcongest-v1r4
head:   07285068a0f1fb7bee052bf5a4b71c4d8d4b2f77
commit: a7f2d5fd13a3022b3906b6f849998b726fa3eb83 [1/5] mm/vmscan: Throttle reclaim until some writeback completes if congested
config: microblaze-buildonly-randconfig-r004-20210929 (attached as .config)
compiler: microblaze-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git/commit/?id=a7f2d5fd13a3022b3906b6f849998b726fa3eb83
        git remote add mel https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git
        git fetch --no-tags mel mm-reclaimcongest-v1r4
        git checkout a7f2d5fd13a3022b3906b6f849998b726fa3eb83
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=microblaze 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

   mm/vmscan.c: In function 'reclaim_throttle':
>> mm/vmscan.c:1015:14: error: variable 'ret' set but not used [-Werror=unused-but-set-variable]
    1015 |         long ret;
         |              ^~~
   mm/vmscan.c: In function 'demote_page_list':
   mm/vmscan.c:1381:13: error: variable 'err' set but not used [-Werror=unused-but-set-variable]
    1381 |         int err;
         |             ^~~
   cc1: all warnings being treated as errors


vim +/ret +1015 mm/vmscan.c

  1008	
  1009	static void
  1010	reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason,
  1011								long timeout)
  1012	{
  1013		wait_queue_head_t *wqh = &pgdat->reclaim_wait;
  1014		unsigned long start = jiffies;
> 1015		long ret;
  1016		DEFINE_WAIT(wait);
  1017	
  1018		atomic_inc(&pgdat->nr_reclaim_throttled);
  1019		WRITE_ONCE(pgdat->nr_reclaim_start,
  1020			 node_page_state(pgdat, NR_THROTTLED_WRITTEN));
  1021	
  1022		prepare_to_wait(wqh, &wait, TASK_INTERRUPTIBLE);
  1023		ret = schedule_timeout(timeout);
  1024		finish_wait(wqh, &wait);
  1025		atomic_dec(&pgdat->nr_reclaim_throttled);
  1026	
  1027		trace_mm_vmscan_throttled(pgdat->node_id, jiffies_to_usecs(timeout),
  1028					jiffies_to_usecs(jiffies - start),
  1029					reason);
  1030	}
  1031	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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