Re: [PATCH v1 12/14] mm: multigenerational lru: user space interface

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

Hi Yu,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/x86/core]
[also build test WARNING on tip/x86/mm tip/sched/core linus/master v5.12-rc2]
[cannot apply to cgroup/for-next tip/perf/core hnaz-linux-mm/master next-20210312]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Yu-Zhao/Multigenerational-LRU/20210313-160036
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git d0962f2b24c99889a386f0658c71535f56358f77
compiler: s390-linux-gcc (GCC) 9.3.0

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


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

   mm/vmscan.c:4107:22: warning: Local variable kswapd shadows outer function [shadowFunction]
    struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
                        ^
   mm/vmscan.c:3909:12: note: Shadowed declaration
   static int kswapd(void *p)
              ^
   mm/vmscan.c:4107:22: note: Shadow variable
    struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
                        ^

vim +6140 mm/vmscan.c

  6106	
  6107	static ssize_t lru_gen_debugfs_write(struct file *file, const char __user *src,
  6108					     size_t len, loff_t *pos)
  6109	{
  6110		void *buf;
  6111		char *cur, *next;
  6112		int err = 0;
  6113	
  6114		buf = kvmalloc(len + 1, GFP_USER);
  6115		if (!buf)
  6116			return -ENOMEM;
  6117	
  6118		if (copy_from_user(buf, src, len)) {
  6119			kvfree(buf);
  6120			return -EFAULT;
  6121		}
  6122	
  6123		next = buf;
  6124		next[len] = '\0';
  6125	
  6126		while ((cur = strsep(&next, ",;\n"))) {
  6127			int n;
  6128			int end;
  6129			char cmd;
  6130			int memcg_id;
  6131			int nid;
  6132			unsigned long seq;
  6133			int swappiness = -1;
  6134			unsigned long nr_to_reclaim = -1;
  6135	
  6136			cur = skip_spaces(cur);
  6137			if (!*cur)
  6138				continue;
  6139	
> 6140			n = sscanf(cur, "%c %u %u %lu %n %u %n %lu %n", &cmd, &memcg_id, &nid,
  6141				   &seq, &end, &swappiness, &end, &nr_to_reclaim, &end);
  6142			if (n < 4 || cur[end]) {
  6143				err = -EINVAL;
  6144				break;
  6145			}
  6146	
  6147			err = advance_seq(cmd, memcg_id, nid, seq, swappiness, nr_to_reclaim);
  6148			if (err)
  6149				break;
  6150		}
  6151	
  6152		kvfree(buf);
  6153	
  6154		return err ? : len;
  6155	}
  6156	

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