[akpm-mm:mm-new 301/315] mm/oom_kill.c:922:12: warning: 'kill_all_shared_mm' defined but not used

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
head:   2c3f468717231305523ddcd94d91c0d5e4a72419
commit: def36547cd98fa3f7ecac1bf860479f500bc6b1e [301/315] mm: process_mrelease: introduce PROCESS_MRELEASE_REAP_KILL flag
config: sh-allnoconfig (https://download.01.org/0day-ci/archive/20260513/202605131940.kEzvUaiR-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260513/202605131940.kEzvUaiR-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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605131940.kEzvUaiR-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/oom_kill.c:922:12: warning: 'kill_all_shared_mm' defined but not used [-Wunused-function]
     922 | static int kill_all_shared_mm(struct task_struct *victim, struct mm_struct *mm)
         |            ^~~~~~~~~~~~~~~~~~


vim +/kill_all_shared_mm +922 mm/oom_kill.c

   912	
   913	/*
   914	 * kill_all_shared_mm - Deliver SIGKILL to all processes sharing the given address space.
   915	 * @victim: the targeted OOM process group leader
   916	 * @mm:     the virtual memory space being reaped
   917	 *
   918	 * Traverse all threads globally and signal any user processes sharing the identical
   919	 * mm footprints, ensuring no concurrent users pin the memory. Skips the system
   920	 * global init and kernel worker threads.
   921	 */
 > 922	static int kill_all_shared_mm(struct task_struct *victim, struct mm_struct *mm)
   923	{
   924		struct task_struct *p;
   925		bool failed = false;
   926	
   927		rcu_read_lock();
   928		for_each_process(p) {
   929			if (!process_shares_mm(p, mm))
   930				continue;
   931			if (is_global_init(p)) {
   932				failed = true;
   933				continue;
   934			}
   935			if (unlikely(p->flags & PF_KTHREAD))
   936				continue;
   937	
   938			if (do_pidfd_send_signal_pidns(task_pid(p), SIGKILL, PIDTYPE_TGID, NULL, 0))
   939				failed = true;
   940		}
   941		rcu_read_unlock();
   942	
   943		return failed ? -EBUSY : 0;
   944	}
   945	

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