Re: [PATCH v12 3/3] mm: Implement precise OOM killer task selection

On 2026-01-11 13:03, kernel test robot wrote:

Hi Mathieu,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20260109]
[cannot apply to akpm-mm/mm-everything kees/for-next/execve tip/sched/core linus/master v6.19-rc4 v6.19-rc3 v6.19-rc2 v6.19-rc4]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mathieu-Desnoyers/lib-Introduce-hierarchical-per-cpu-counters/20260111-231206
base:   next-20260109
patch link:    https://lore.kernel.org/r/20260111150249.1222944-4-mathieu.desnoyers%40efficios.com
patch subject: [PATCH v12 3/3] mm: Implement precise OOM killer task selection
config: arm-randconfig-001-20260112 (https://download.01.org/0day-ci/archive/20260112/202601120124.RK3AWOwu-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260112/202601120124.RK3AWOwu-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202601120124.RK3AWOwu-lkp@intel.com/ (local)

All warnings (new ones prefixed by >>):

quoted

quoted

kernel/fork.c:637:6: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]

      635 |                         pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld Comm:%s Pid:%d\n",
          |                                                                                ~~~
          |                                                                                %d
      636 |                                  mm, resident_page_types[i],
      637 |                                  percpu_counter_tree_precise_sum(&mm->rss_stat[i]),
          |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    include/linux/printk.h:534:35: note: expanded from macro 'pr_alert'
      534 |         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
          |                                  ~~~     ^~~~~~~~~~~
    include/linux/printk.h:511:60: note: expanded from macro 'printk'
      511 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
          |                                                     ~~~    ^~~~~~~~~~~
    include/linux/printk.h:483:19: note: expanded from macro 'printk_index_wrap'
      483 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
          |                         ~~~~    ^~~~~~~~~~~
    1 warning generated.

That's percpu_counter_tree_precise_sum which needs to return a "long".
Will fix.

--

quoted

quoted

mm/oom_kill.c:351:6: warning: variable 'points_min' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]

      351 |         if (oom_task_origin(task)) {
          |             ^~~~~~~~~~~~~~~~~~~~~
    mm/oom_kill.c:392:22: note: uninitialized use occurs here
      392 |         oc->chosen_points = points_min;
          |                             ^~~~~~~~~~
    mm/oom_kill.c:351:2: note: remove the 'if' if its condition is always false
      351 |         if (oom_task_origin(task)) {
          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      352 |                 points = LONG_MAX;

I need to change this to "points_min = LONG_MAX". Will fix.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com