mm: add process info to bad rss-counter warning

Enhance the debugging information in check_mm() by including the process
name and PID when reporting bad rss-counter states.  This helps identify
which process is associated with the memory accounting issue.

Link: https://lkml.kernel.org/r/20250723100901.1909683-1-liuqiye2025@163.com
Signed-off-by: Xuanye Liu <liuqiye2025@163.com>
Acked-by: SeongJae Park <sj@kernel.org>
Cc: Ben Segall <bsegall@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index 1ee8eb11f38bae1d2eb6de9494aea94b7a19e6c3..f799d128b968ed894789220809543de5356dca2d 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -585,9 +585,12 @@ static void check_mm(struct mm_struct *mm)
        for (i = 0; i < NR_MM_COUNTERS; i++) {
                long x = percpu_counter_sum(&mm->rss_stat[i]);
 
-               if (unlikely(x))
-                       pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld\n",
-                                mm, resident_page_types[i], x);
+               if (unlikely(x)) {
+                       pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld Comm:%s Pid:%d\n",
+                                mm, resident_page_types[i], x,
+                                current->comm,
+                                task_pid_nr(current));
+               }
        }
 
        if (mm_pgtables_bytes(mm))