Re: [RFC PATCH] mm: introduce defer free for cma

[kernel test robot <lkp@intel.com>]

Hi zhaoyang.huang,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/zhaoyang-huang/mm-introduce-defer-free-for-cma/20230407-184459
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/1680864131-4675-1-git-send-email-zhaoyang.huang%40unisoc.com
patch subject: [RFC PATCH] mm: introduce defer free for cma
config: i386-randconfig-a001-20230403 (https://download.01.org/0day-ci/archive/20230407/202304072120.1qQfF86Z-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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://github.com/intel-lab-lkp/linux/commit/7abee7e8d17803e68bfff3de73df6a1dff270ff6
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review zhaoyang-huang/mm-introduce-defer-free-for-cma/20230407-184459
        git checkout 7abee7e8d17803e68bfff3de73df6a1dff270ff6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304072120.1qQfF86Z-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/cma.c:165:19: warning: operator '<<' has lower precedence than '-'; '-' will be evaluated first [-Wshift-op-parentheses]
           val = cma->count - (u64)used << cma->order_per_bit;
                 ~~~~~~~~~~~^~~~~~~~~~~ ~~
   mm/cma.c:165:19: note: place parentheses around the '-' expression to silence this warning
           val = cma->count - (u64)used << cma->order_per_bit;
                            ^
                 (                     )
   mm/cma.c:157:22: warning: unused function 'cma_free_get' [-Wunused-function]
   static unsigned long cma_free_get(struct cma *cma)
                        ^
   2 warnings generated.


vim +165 mm/cma.c

   156	
   157	static unsigned long cma_free_get(struct cma *cma)
   158	{
   159		unsigned long used;
   160		unsigned long val;
   161	
   162		spin_lock_irq(&cma->lock);
   163		/* pages counter is smaller than sizeof(int) */
   164		used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
 > 165		val = cma->count - (u64)used << cma->order_per_bit;
   166		spin_unlock_irq(&cma->lock);
   167	
   168		return val;
   169	}
   170	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests