mm/mglru: improve reset_mm_stats()

struct lruvec* is already a field of struct lru_gen_mm_walk.  Remove the
parameter struct lruvec* into functions that already have access to struct
lru_gen_mm_walk*.

Also, we do not need to handle reset histogram stats when
!should_walk_mmu().  Remove the call to reset_mm_stats() in
iterate_mm_list_nowalk().

Link: https://lkml.kernel.org/r/20240214060538.3524462-4-kinseyho@google.com
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Donet Tom <donettom@linux.vnet.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6d1704e7bfe0823ab55fa5d710fd68a1b731df9a..1bec586d854ea0eece104092cf1d4b37707bb32c 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2879,38 +2879,37 @@ static struct mm_struct *get_next_mm(struct lru_gen_mm_walk *walk)
 
 #endif
 
-static void reset_mm_stats(struct lruvec *lruvec, struct lru_gen_mm_walk *walk, bool last)
+static void reset_mm_stats(struct lru_gen_mm_walk *walk, bool last)
 {
        int i;
        int hist;
+       struct lruvec *lruvec = walk->lruvec;
        struct lru_gen_mm_state *mm_state = get_mm_state(lruvec);
 
        lockdep_assert_held(&get_mm_list(lruvec_memcg(lruvec))->lock);
 
-       if (walk) {
-               hist = lru_hist_from_seq(walk->max_seq);
+       hist = lru_hist_from_seq(walk->max_seq);
 
-               for (i = 0; i < NR_MM_STATS; i++) {
-                       WRITE_ONCE(mm_state->stats[hist][i],
-                                  mm_state->stats[hist][i] + walk->mm_stats[i]);
-                       walk->mm_stats[i] = 0;
-               }
+       for (i = 0; i < NR_MM_STATS; i++) {
+               WRITE_ONCE(mm_state->stats[hist][i],
+                          mm_state->stats[hist][i] + walk->mm_stats[i]);
+               walk->mm_stats[i] = 0;
        }
 
        if (NR_HIST_GENS > 1 && last) {
-               hist = lru_hist_from_seq(mm_state->seq + 1);
+               hist = lru_hist_from_seq(walk->max_seq + 1);
 
                for (i = 0; i < NR_MM_STATS; i++)
                        WRITE_ONCE(mm_state->stats[hist][i], 0);
        }
 }
 
-static bool iterate_mm_list(struct lruvec *lruvec, struct lru_gen_mm_walk *walk,
-                           struct mm_struct **iter)
+static bool iterate_mm_list(struct lru_gen_mm_walk *walk, struct mm_struct **iter)
 {
        bool first = false;
        bool last = false;
        struct mm_struct *mm = NULL;
+       struct lruvec *lruvec = walk->lruvec;
        struct mem_cgroup *memcg = lruvec_memcg(lruvec);
        struct lru_gen_mm_list *mm_list = get_mm_list(memcg);
        struct lru_gen_mm_state *mm_state = get_mm_state(lruvec);
@@ -2954,7 +2953,7 @@ static bool iterate_mm_list(struct lruvec *lruvec, struct lru_gen_mm_walk *walk,
        } while (!(mm = get_next_mm(walk)));
 done:
        if (*iter || last)
-               reset_mm_stats(lruvec, walk, last);
+               reset_mm_stats(walk, last);
 
        spin_unlock(&mm_list->lock);
 
@@ -2984,7 +2983,6 @@ static bool iterate_mm_list_nowalk(struct lruvec *lruvec, unsigned long max_seq)
                mm_state->head = NULL;
                mm_state->tail = NULL;
                WRITE_ONCE(mm_state->seq, mm_state->seq + 1);
-               reset_mm_stats(lruvec, NULL, true);
                success = true;
        }
 
@@ -3159,9 +3157,10 @@ static void update_batch_size(struct lru_gen_mm_walk *walk, struct folio *folio,
        walk->nr_pages[new_gen][type][zone] += delta;
 }
 
-static void reset_batch_size(struct lruvec *lruvec, struct lru_gen_mm_walk *walk)
+static void reset_batch_size(struct lru_gen_mm_walk *walk)
 {
        int gen, type, zone;
+       struct lruvec *lruvec = walk->lruvec;
        struct lru_gen_folio *lrugen = &lruvec->lrugen;
 
        walk->batched = 0;
@@ -3591,7 +3590,7 @@ done:
        return -EAGAIN;
 }
 
-static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_mm_walk *walk)
+static void walk_mm(struct mm_struct *mm, struct lru_gen_mm_walk *walk)
 {
        static const struct mm_walk_ops mm_walk_ops = {
                .test_walk = should_skip_vma,
@@ -3600,6 +3599,7 @@ static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_
        };
 
        int err;
+       struct lruvec *lruvec = walk->lruvec;
        struct mem_cgroup *memcg = lruvec_memcg(lruvec);
 
        walk->next_addr = FIRST_USER_ADDRESS;
@@ -3628,7 +3628,7 @@ static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_
 
                if (walk->batched) {
                        spin_lock_irq(&lruvec->lru_lock);
-                       reset_batch_size(lruvec, walk);
+                       reset_batch_size(walk);
                        spin_unlock_irq(&lruvec->lru_lock);
                }
 
@@ -3856,9 +3856,9 @@ static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
        walk->force_scan = force_scan;
 
        do {
-               success = iterate_mm_list(lruvec, walk, &mm);
+               success = iterate_mm_list(walk, &mm);
                if (mm)
-                       walk_mm(lruvec, mm, walk);
+                       walk_mm(mm, walk);
        } while (mm);
 done:
        if (success) {
@@ -4558,8 +4558,10 @@ retry:
        move_folios_to_lru(lruvec, &list);
 
        walk = current->reclaim_state->mm_walk;
-       if (walk && walk->batched)
-               reset_batch_size(lruvec, walk);
+       if (walk && walk->batched) {
+               walk->lruvec = lruvec;
+               reset_batch_size(walk);
+       }
 
        item = PGSTEAL_KSWAPD + reclaimer_offset();
        if (!cgroup_reclaim(sc))