Re: fs/proc/base.c:3279:4-39: opportunity for str_yes_no(mm_flags_test ( MMF_VM_MERGE_ANY , mm )) (fwd)

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

On Thu, Oct 23, 2025 at 04:58:56PM +0800, Julia Lawall wrote:
>
>
> ---------- Forwarded message ----------
> Date: Thu, 23 Oct 2025 15:29:09 +0800
> From: kernel test robot <lkp@intel.com>
> To: oe-kbuild@lists.linux.dev
> Cc: lkp@intel.com, Julia Lawall <julia.lawall@inria.fr>
> Subject: fs/proc/base.c:3279:4-39: opportunity for str_yes_no(mm_flags_test (
>     MMF_VM_MERGE_ANY , mm ))
>
> BCC: lkp@intel.com
> CC: oe-kbuild-all@lists.linux.dev
> CC: linux-kernel@vger.kernel.org
> TO: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: Linux Memory Management List <linux-mm@kvack.org>
> CC: "Liam R. Howlett" <Liam.Howlett@oracle.com>
> CC: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
>
> Hi Lorenzo,
>
> FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   43e9ad0c55a369ecc84a4788d06a8a6bfa634f1c
> commit: d14d3f535e13ff0661b9a74133a8d6b9f9950712 mm: convert remaining users to mm_flags_*() accessors
> date:   6 weeks ago
> :::::: branch date: 6 hours ago
> :::::: commit date: 6 weeks ago
> config: m68k-randconfig-r063-20251023 (https://download.01.org/0day-ci/archive/20251023/202510231541.uVpbrSce-lkp@intel.com/config)
> compiler: m68k-linux-gcc (GCC) 8.5.0
>
> 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>
> | Reported-by: Julia Lawall <julia.lawall@inria.fr>
> | Closes: https://lore.kernel.org/r/202510231541.uVpbrSce-lkp@intel.com/
>
> cocci warnings: (new ones prefixed by >>)
>    fs/proc/base.c:3286:4-29: opportunity for str_yes_no(ksm_process_mergeable ( mm ))
> >> fs/proc/base.c:3279:4-39: opportunity for str_yes_no(mm_flags_test ( MMF_VM_MERGE_ANY , mm ))

Thanks, I just happened to update this code to use the new mm flag
interface, so this was existing code :)

Cheers, Lorenzo

>
> vim +3279 fs/proc/base.c
>
> 7c23b3300116907 Josh Poimboeuf  2017-02-13  3251
> 7609385337a4feb xu xin          2022-04-28  3252  #ifdef CONFIG_KSM
> 7609385337a4feb xu xin          2022-04-28  3253  static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
> 7609385337a4feb xu xin          2022-04-28  3254  				struct pid *pid, struct task_struct *task)
> 7609385337a4feb xu xin          2022-04-28  3255  {
> 7609385337a4feb xu xin          2022-04-28  3256  	struct mm_struct *mm;
> 7609385337a4feb xu xin          2022-04-28  3257
> 7609385337a4feb xu xin          2022-04-28  3258  	mm = get_task_mm(task);
> 7609385337a4feb xu xin          2022-04-28  3259  	if (mm) {
> 7609385337a4feb xu xin          2022-04-28  3260  		seq_printf(m, "%lu\n", mm->ksm_merging_pages);
> 7609385337a4feb xu xin          2022-04-28  3261  		mmput(mm);
> 7609385337a4feb xu xin          2022-04-28  3262  	}
> 7609385337a4feb xu xin          2022-04-28  3263
> 7609385337a4feb xu xin          2022-04-28  3264  	return 0;
> 7609385337a4feb xu xin          2022-04-28  3265  }
> cb4df4cae4f2bd8 xu xin          2022-08-30  3266  static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
> cb4df4cae4f2bd8 xu xin          2022-08-30  3267  				struct pid *pid, struct task_struct *task)
> cb4df4cae4f2bd8 xu xin          2022-08-30  3268  {
> cb4df4cae4f2bd8 xu xin          2022-08-30  3269  	struct mm_struct *mm;
> 3ab76c767bc783c xu xin          2025-01-10  3270  	int ret = 0;
> cb4df4cae4f2bd8 xu xin          2022-08-30  3271
> cb4df4cae4f2bd8 xu xin          2022-08-30  3272  	mm = get_task_mm(task);
> cb4df4cae4f2bd8 xu xin          2022-08-30  3273  	if (mm) {
> cb4df4cae4f2bd8 xu xin          2022-08-30  3274  		seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
> c2dc78b86e0821e Chengming Zhou  2024-05-28  3275  		seq_printf(m, "ksm_zero_pages %ld\n", mm_ksm_zero_pages(mm));
> d21077fbc2fc987 Stefan Roesch   2023-04-17  3276  		seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages);
> d21077fbc2fc987 Stefan Roesch   2023-04-17  3277  		seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm));
> 3ab76c767bc783c xu xin          2025-01-10  3278  		seq_printf(m, "ksm_merge_any: %s\n",
> d14d3f535e13ff0 Lorenzo Stoakes 2025-08-12 @3279  				mm_flags_test(MMF_VM_MERGE_ANY, mm) ? "yes" : "no");
> 3ab76c767bc783c xu xin          2025-01-10  3280  		ret = mmap_read_lock_killable(mm);
> 3ab76c767bc783c xu xin          2025-01-10  3281  		if (ret) {
> 3ab76c767bc783c xu xin          2025-01-10  3282  			mmput(mm);
> 3ab76c767bc783c xu xin          2025-01-10  3283  			return ret;
> 3ab76c767bc783c xu xin          2025-01-10  3284  		}
> 3ab76c767bc783c xu xin          2025-01-10  3285  		seq_printf(m, "ksm_mergeable: %s\n",
> 3ab76c767bc783c xu xin          2025-01-10  3286  				ksm_process_mergeable(mm) ? "yes" : "no");
> 3ab76c767bc783c xu xin          2025-01-10  3287  		mmap_read_unlock(mm);
> cb4df4cae4f2bd8 xu xin          2022-08-30  3288  		mmput(mm);
> cb4df4cae4f2bd8 xu xin          2022-08-30  3289  	}
> cb4df4cae4f2bd8 xu xin          2022-08-30  3290
> cb4df4cae4f2bd8 xu xin          2022-08-30  3291  	return 0;
> cb4df4cae4f2bd8 xu xin          2022-08-30  3292  }
> 7609385337a4feb xu xin          2022-04-28  3293  #endif /* CONFIG_KSM */
> 7609385337a4feb xu xin          2022-04-28  3294
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki