From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: memcontrol: make the slab calculation consistent
Although the ratio of the slab is one, we also should read the ratio from
the related memory_stats instead of hard-coding. And the local variable
of size is already the value of slab_unreclaimable. So we do not need to
read again.
To do this we need some code like below:
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
- size = memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) +
- memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE_B);
+ VM_BUG_ON(i < 1);
+ VM_BUG_ON(memory_stats[i - 1].idx != NR_SLAB_RECLAIMABLE_B);
+ size += memcg_page_state(memcg, memory_stats[i - 1].idx) *
+ memory_stats[i - 1].ratio;
It requires a series of VM_BUG_ONs or comments to ensure these two items
are actually adjacent and in the right order. So it would probably be
easier to implement this using a wrapper that has a big switch() for unit
conversion.
More details about this discussion can refer to:
https://lore.kernel.org/patchwork/patch/1348611/
This would fix the ratio inconsistency and get rid of the order
guarantee.
Link: https://lkml.kernel.org/r/20201228164110.2838-8-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Feng Tang <feng.tang@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Cc: Pankaj Gupta <pankaj.gupta@xxxxxxxxxxxxxxx>
Cc: Rafael. J. Wysocki <rafael@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 105 ++++++++++++++++++++++++++++------------------
1 file changed, 66 insertions(+), 39 deletions(-)
--- a/mm/memcontrol.c~mm-memcontrol-make-the-slab-calculation-consistent
+++ a/mm/memcontrol.c
@@ -1512,49 +1512,71 @@ static bool mem_cgroup_wait_acct_move(st
struct memory_stat {
const char *name;
- unsigned int ratio;
unsigned int idx;
};
static const struct memory_stat memory_stats[] = {
- { "anon", PAGE_SIZE, NR_ANON_MAPPED },
- { "file", PAGE_SIZE, NR_FILE_PAGES },
- { "kernel_stack", 1024, NR_KERNEL_STACK_KB },
- { "pagetables", PAGE_SIZE, NR_PAGETABLE },
- { "percpu", 1, MEMCG_PERCPU_B },
- { "sock", PAGE_SIZE, MEMCG_SOCK },
- { "shmem", PAGE_SIZE, NR_SHMEM },
- { "file_mapped", PAGE_SIZE, NR_FILE_MAPPED },
- { "file_dirty", PAGE_SIZE, NR_FILE_DIRTY },
- { "file_writeback", PAGE_SIZE, NR_WRITEBACK },
+ { "anon", NR_ANON_MAPPED },
+ { "file", NR_FILE_PAGES },
+ { "kernel_stack", NR_KERNEL_STACK_KB },
+ { "pagetables", NR_PAGETABLE },
+ { "percpu", MEMCG_PERCPU_B },
+ { "sock", MEMCG_SOCK },
+ { "shmem", NR_SHMEM },
+ { "file_mapped", NR_FILE_MAPPED },
+ { "file_dirty", NR_FILE_DIRTY },
+ { "file_writeback", NR_WRITEBACK },
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- { "anon_thp", PAGE_SIZE, NR_ANON_THPS },
- { "file_thp", PAGE_SIZE, NR_FILE_THPS },
- { "shmem_thp", PAGE_SIZE, NR_SHMEM_THPS },
+ { "anon_thp", NR_ANON_THPS },
+ { "file_thp", NR_FILE_THPS },
+ { "shmem_thp", NR_SHMEM_THPS },
#endif
- { "inactive_anon", PAGE_SIZE, NR_INACTIVE_ANON },
- { "active_anon", PAGE_SIZE, NR_ACTIVE_ANON },
- { "inactive_file", PAGE_SIZE, NR_INACTIVE_FILE },
- { "active_file", PAGE_SIZE, NR_ACTIVE_FILE },
- { "unevictable", PAGE_SIZE, NR_UNEVICTABLE },
-
- /*
- * Note: The slab_reclaimable and slab_unreclaimable must be
- * together and slab_reclaimable must be in front.
- */
- { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B },
- { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B },
+ { "inactive_anon", NR_INACTIVE_ANON },
+ { "active_anon", NR_ACTIVE_ANON },
+ { "inactive_file", NR_INACTIVE_FILE },
+ { "active_file", NR_ACTIVE_FILE },
+ { "unevictable", NR_UNEVICTABLE },
+ { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B },
+ { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B },
/* The memory events */
- { "workingset_refault_anon", 1, WORKINGSET_REFAULT_ANON },
- { "workingset_refault_file", 1, WORKINGSET_REFAULT_FILE },
- { "workingset_activate_anon", 1, WORKINGSET_ACTIVATE_ANON },
- { "workingset_activate_file", 1, WORKINGSET_ACTIVATE_FILE },
- { "workingset_restore_anon", 1, WORKINGSET_RESTORE_ANON },
- { "workingset_restore_file", 1, WORKINGSET_RESTORE_FILE },
- { "workingset_nodereclaim", 1, WORKINGSET_NODERECLAIM },
+ { "workingset_refault_anon", WORKINGSET_REFAULT_ANON },
+ { "workingset_refault_file", WORKINGSET_REFAULT_FILE },
+ { "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON },
+ { "workingset_activate_file", WORKINGSET_ACTIVATE_FILE },
+ { "workingset_restore_anon", WORKINGSET_RESTORE_ANON },
+ { "workingset_restore_file", WORKINGSET_RESTORE_FILE },
+ { "workingset_nodereclaim", WORKINGSET_NODERECLAIM },
};
+/* Translate stat items to the correct unit for memory.stat output */
+static int memcg_page_state_unit(int item)
+{
+ switch (item) {
+ case MEMCG_PERCPU_B:
+ case NR_SLAB_RECLAIMABLE_B:
+ case NR_SLAB_UNRECLAIMABLE_B:
+ case WORKINGSET_REFAULT_ANON:
+ case WORKINGSET_REFAULT_FILE:
+ case WORKINGSET_ACTIVATE_ANON:
+ case WORKINGSET_ACTIVATE_FILE:
+ case WORKINGSET_RESTORE_ANON:
+ case WORKINGSET_RESTORE_FILE:
+ case WORKINGSET_NODERECLAIM:
+ return 1;
+ case NR_KERNEL_STACK_KB:
+ return SZ_1K;
+ default:
+ return PAGE_SIZE;
+ }
+}
+
+static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg,
+ int item)
+{
+ return memcg_page_state(memcg, item) * memcg_page_state_unit(item);
+}
+
static char *memory_stat_format(struct mem_cgroup *memcg)
{
struct seq_buf s;
@@ -1578,13 +1600,12 @@ static char *memory_stat_format(struct m
for (i = 0; i < ARRAY_SIZE(memory_stats); i++) {
u64 size;
- size = memcg_page_state(memcg, memory_stats[i].idx);
- size *= memory_stats[i].ratio;
+ size = memcg_page_state_output(memcg, memory_stats[i].idx);
seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size);
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
- size = memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) +
- memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE_B);
+ size += memcg_page_state_output(memcg,
+ NR_SLAB_RECLAIMABLE_B);
seq_buf_printf(&s, "slab %llu\n", size);
}
}
@@ -6375,6 +6396,12 @@ static int memory_stat_show(struct seq_f
}
#ifdef CONFIG_NUMA
+static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec,
+ int item)
+{
+ return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item);
+}
+
static int memory_numa_stat_show(struct seq_file *m, void *v)
{
int i;
@@ -6392,8 +6419,8 @@ static int memory_numa_stat_show(struct
struct lruvec *lruvec;
lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
- size = lruvec_page_state(lruvec, memory_stats[i].idx);
- size *= memory_stats[i].ratio;
+ size = lruvec_page_state_output(lruvec,
+ memory_stats[i].idx);
seq_printf(m, " N%d=%llu", nid, size);
}
seq_putc(m, '\n');
_
