The patch titled
Subject: mm/mglru: improve struct lru_gen_mm_walk
has been added to the -mm mm-unstable branch. Its filename is
mm-mglru-improve-struct-lru_gen_mm_walk.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mglru-improve-struct-lru_gen_mm_walk.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Kinsey Ho <kinseyho@xxxxxxxxxx>
Subject: mm/mglru: improve struct lru_gen_mm_walk
Date: Wed, 14 Feb 2024 06:05:37 +0000
Rename max_seq to seq in struct lru_gen_mm_walk to keep consistent with
struct lru_gen_mm_state. Note that seq is not always up to date with
max_seq from lru_gen_folio.
No functional changes.
Link: https://lkml.kernel.org/r/20240214060538.3524462-5-kinseyho@xxxxxxxxxx
Signed-off-by: Kinsey Ho <kinseyho@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Donet Tom <donettom@xxxxxxxxxxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmzone.h | 6 ++--
mm/vmscan.c | 50 ++++++++++++++++++++-------------------
2 files changed, 29 insertions(+), 27 deletions(-)
--- a/include/linux/mmzone.h~mm-mglru-improve-struct-lru_gen_mm_walk
+++ a/include/linux/mmzone.h
@@ -464,7 +464,7 @@ enum {
#define NR_BLOOM_FILTERS 2
struct lru_gen_mm_state {
- /* set to max_seq after each iteration */
+ /* synced with max_seq after each iteration */
unsigned long seq;
/* where the current iteration continues after */
struct list_head *head;
@@ -479,8 +479,8 @@ struct lru_gen_mm_state {
struct lru_gen_mm_walk {
/* the lruvec under reclaim */
struct lruvec *lruvec;
- /* unstable max_seq from lru_gen_folio */
- unsigned long max_seq;
+ /* max_seq from lru_gen_folio: can be out of date */
+ unsigned long seq;
/* the next address within an mm to scan */
unsigned long next_addr;
/* to batch promoted pages */
--- a/mm/vmscan.c~mm-mglru-improve-struct-lru_gen_mm_walk
+++ a/mm/vmscan.c
@@ -2889,7 +2889,7 @@ static void reset_mm_stats(struct lru_ge
lockdep_assert_held(&get_mm_list(lruvec_memcg(lruvec))->lock);
- hist = lru_hist_from_seq(walk->max_seq);
+ hist = lru_hist_from_seq(walk->seq);
for (i = 0; i < NR_MM_STATS; i++) {
WRITE_ONCE(mm_state->stats[hist][i],
@@ -2898,7 +2898,7 @@ static void reset_mm_stats(struct lru_ge
}
if (NR_HIST_GENS > 1 && last) {
- hist = lru_hist_from_seq(walk->max_seq + 1);
+ hist = lru_hist_from_seq(walk->seq + 1);
for (i = 0; i < NR_MM_STATS; i++)
WRITE_ONCE(mm_state->stats[hist][i], 0);
@@ -2927,9 +2927,9 @@ static bool iterate_mm_list(struct lru_g
*/
spin_lock(&mm_list->lock);
- VM_WARN_ON_ONCE(mm_state->seq + 1 < walk->max_seq);
+ VM_WARN_ON_ONCE(mm_state->seq + 1 < walk->seq);
- if (walk->max_seq <= mm_state->seq)
+ if (walk->seq <= mm_state->seq)
goto done;
if (!mm_state->head)
@@ -2959,7 +2959,7 @@ done:
spin_unlock(&mm_list->lock);
if (mm && first)
- reset_bloom_filter(mm_state, walk->max_seq + 1);
+ reset_bloom_filter(mm_state, walk->seq + 1);
if (*iter)
mmput_async(*iter);
@@ -2969,7 +2969,7 @@ done:
return last;
}
-static bool iterate_mm_list_nowalk(struct lruvec *lruvec, unsigned long max_seq)
+static bool iterate_mm_list_nowalk(struct lruvec *lruvec, unsigned long seq)
{
bool success = false;
struct mem_cgroup *memcg = lruvec_memcg(lruvec);
@@ -2978,9 +2978,9 @@ static bool iterate_mm_list_nowalk(struc
spin_lock(&mm_list->lock);
- VM_WARN_ON_ONCE(mm_state->seq + 1 < max_seq);
+ VM_WARN_ON_ONCE(mm_state->seq + 1 < seq);
- if (max_seq > mm_state->seq) {
+ if (seq > mm_state->seq) {
mm_state->head = NULL;
mm_state->tail = NULL;
WRITE_ONCE(mm_state->seq, mm_state->seq + 1);
@@ -3331,7 +3331,8 @@ static bool walk_pte_range(pmd_t *pmd, u
struct lru_gen_mm_walk *walk = args->private;
struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec);
struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
- int old_gen, new_gen = lru_gen_from_seq(walk->max_seq);
+ DEFINE_MAX_SEQ(walk->lruvec);
+ int old_gen, new_gen = lru_gen_from_seq(max_seq);
pte = pte_offset_map_nolock(args->mm, pmd, start & PMD_MASK, &ptl);
if (!pte)
@@ -3398,7 +3399,8 @@ static void walk_pmd_range_locked(pud_t
struct lru_gen_mm_walk *walk = args->private;
struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec);
struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
- int old_gen, new_gen = lru_gen_from_seq(walk->max_seq);
+ DEFINE_MAX_SEQ(walk->lruvec);
+ int old_gen, new_gen = lru_gen_from_seq(max_seq);
VM_WARN_ON_ONCE(pud_leaf(*pud));
@@ -3529,7 +3531,7 @@ restart:
walk_pmd_range_locked(pud, addr, vma, args, bitmap, &first);
}
- if (!walk->force_scan && !test_bloom_filter(mm_state, walk->max_seq, pmd + i))
+ if (!walk->force_scan && !test_bloom_filter(mm_state, walk->seq, pmd + i))
continue;
walk->mm_stats[MM_NONLEAF_FOUND]++;
@@ -3540,7 +3542,7 @@ restart:
walk->mm_stats[MM_NONLEAF_ADDED]++;
/* carry over to the next generation */
- update_bloom_filter(mm_state, walk->max_seq + 1, pmd + i);
+ update_bloom_filter(mm_state, walk->seq + 1, pmd + i);
}
walk_pmd_range_locked(pud, -1, vma, args, bitmap, &first);
@@ -3611,7 +3613,7 @@ static void walk_mm(struct mm_struct *mm
err = -EBUSY;
/* another thread might have called inc_max_seq() */
- if (walk->max_seq != max_seq)
+ if (walk->seq != max_seq)
break;
/* folio_update_gen() requires stable folio_memcg() */
@@ -3748,7 +3750,7 @@ next:
return success;
}
-static bool inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
+static bool inc_max_seq(struct lruvec *lruvec, unsigned long seq,
bool can_swap, bool force_scan)
{
bool success;
@@ -3756,14 +3758,14 @@ static bool inc_max_seq(struct lruvec *l
int type, zone;
struct lru_gen_folio *lrugen = &lruvec->lrugen;
restart:
- if (max_seq < READ_ONCE(lrugen->max_seq))
+ if (seq < READ_ONCE(lrugen->max_seq))
return false;
spin_lock_irq(&lruvec->lru_lock);
VM_WARN_ON_ONCE(!seq_is_valid(lruvec));
- success = max_seq == lrugen->max_seq;
+ success = seq == lrugen->max_seq;
if (!success)
goto unlock;
@@ -3816,7 +3818,7 @@ unlock:
return success;
}
-static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
+static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long seq,
bool can_swap, bool force_scan)
{
bool success;
@@ -3825,13 +3827,13 @@ static bool try_to_inc_max_seq(struct lr
struct lru_gen_folio *lrugen = &lruvec->lrugen;
struct lru_gen_mm_state *mm_state = get_mm_state(lruvec);
- VM_WARN_ON_ONCE(max_seq > READ_ONCE(lrugen->max_seq));
+ VM_WARN_ON_ONCE(seq > READ_ONCE(lrugen->max_seq));
if (!mm_state)
- return inc_max_seq(lruvec, max_seq, can_swap, force_scan);
+ return inc_max_seq(lruvec, seq, can_swap, force_scan);
/* see the comment in iterate_mm_list() */
- if (max_seq <= READ_ONCE(mm_state->seq))
+ if (seq <= READ_ONCE(mm_state->seq))
return false;
/*
@@ -3841,18 +3843,18 @@ static bool try_to_inc_max_seq(struct lr
* is less efficient, but it avoids bursty page faults.
*/
if (!should_walk_mmu()) {
- success = iterate_mm_list_nowalk(lruvec, max_seq);
+ success = iterate_mm_list_nowalk(lruvec, seq);
goto done;
}
walk = set_mm_walk(NULL, true);
if (!walk) {
- success = iterate_mm_list_nowalk(lruvec, max_seq);
+ success = iterate_mm_list_nowalk(lruvec, seq);
goto done;
}
walk->lruvec = lruvec;
- walk->max_seq = max_seq;
+ walk->seq = seq;
walk->can_swap = can_swap;
walk->force_scan = force_scan;
@@ -3863,7 +3865,7 @@ static bool try_to_inc_max_seq(struct lr
} while (mm);
done:
if (success) {
- success = inc_max_seq(lruvec, max_seq, can_swap, force_scan);
+ success = inc_max_seq(lruvec, seq, can_swap, force_scan);
WARN_ON_ONCE(!success);
}
_
Patches currently in -mm which might be from kinseyho@xxxxxxxxxx are
mm-mglru-drop-unused-parameter.patch
mm-mglru-improve-should_run_aging.patch
mm-mglru-improve-reset_mm_stats.patch
mm-mglru-improve-struct-lru_gen_mm_walk.patch
mm-mglru-improve-swappiness-handling.patch
