[RFC PATCH 2/7] mm: move check_mm to memory.c

Kairui Song
2022-07-28T20:45:37Z

No function change, make it possible to do extra mm operation on mm exit,
prepare for following commits.

Signed-off-by: Kairui Song <kasong@tencent.com>
---
include/linux/mm.h | 3 +++
kernel/fork.c | 33 ---------------------------------
mm/memory.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 35 insertions(+), 33 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6346f7e77dc7..81ad91621078 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1993,6 +1993,9 @@ static inline bool get_user_page_fast_only(unsigned long addr,
{
return get_user_pages_fast_only(addr, 1, gup_flags, pagep) == 1;
}
+
+void check_mm(struct mm_struct *mm);
+
/*
* per-process(per-mm_struct) statistics.
*/
diff --git a/kernel/fork.c b/kernel/fork.c
index c090ebd55063..86a239772208 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -128,15 +128,6 @@ int nr_threads; /* The idle threads do not count.. */

static int max_threads; /* tunable limit on nr_threads */

-#define NAMED_ARRAY_INDEX(x) [x] = __stringify(x)
-
-static const char * const resident_page_types[] = {
- NAMED_ARRAY_INDEX(MM_FILEPAGES),
- NAMED_ARRAY_INDEX(MM_ANONPAGES),
- NAMED_ARRAY_INDEX(MM_SWAPENTS),
- NAMED_ARRAY_INDEX(MM_SHMEMPAGES),
-};
-
DEFINE_PER_CPU(unsigned long, process_counts) = 0;

__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
@@ -748,30 +739,6 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
#define mm_free_pgd(mm)
#endif /* CONFIG_MMU */

-static void check_mm(struct mm_struct *mm)
-{
- int i;
-
- BUILD_BUG_ON_MSG(ARRAY_SIZE(resident_page_types) != NR_MM_COUNTERS,
- "Please make sure 'struct resident_page_types[]' is updated as well");
-
- for (i = 0; i < NR_MM_COUNTERS; i++) {
- long x = atomic_long_read(&mm->rss_stat.count[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 (mm_pgtables_bytes(mm))
- pr_alert("BUG: non-zero pgtables_bytes on freeing mm: %ld\n",
- mm_pgtables_bytes(mm));
-
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
- VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
-#endif
-}
-
#define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
#define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))

diff --git a/mm/memory.c b/mm/memory.c
index 6bf7826e666b..c0597214f9b3 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -179,6 +179,38 @@ void mm_trace_rss_stat(struct mm_struct *mm, int member, long count)
#define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member)
#define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member)

+#define NAMED_ARRAY_INDEX(x) [x] = __stringify(x)
+static const char * const resident_page_types[] = {
+ NAMED_ARRAY_INDEX(MM_FILEPAGES),
+ NAMED_ARRAY_INDEX(MM_ANONPAGES),
+ NAMED_ARRAY_INDEX(MM_SWAPENTS),
+ NAMED_ARRAY_INDEX(MM_SHMEMPAGES),
+};
+
+void check_mm(struct mm_struct *mm)
+{
+ int i;
+
+ BUILD_BUG_ON_MSG(ARRAY_SIZE(resident_page_types) != NR_MM_COUNTERS,
+ "Please make sure 'struct resident_page_types[]' is updated as well");
+
+ for (i = 0; i < NR_MM_COUNTERS; i++) {
+ long x = atomic_long_read(&mm->rss_stat.count[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 (mm_pgtables_bytes(mm))
+ pr_alert("BUG: non-zero pgtables_bytes on freeing mm: %ld\n",
+ mm_pgtables_bytes(mm));
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+ VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
+#endif
+}
+
/*
* Note: this doesn't free the actual pages themselves. That
* has been handled earlier when unmapping all the memory regions.
--
2.35.2