Commit fff66b79 authored by Muchun Song's avatar Muchun Song Committed by Linus Torvalds

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@bytedance.comSigned-off-by: default avatarMuchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 380780e7
......@@ -1512,49 +1512,71 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
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 mem_cgroup *memcg)
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_file *m, void *v)
}
#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 seq_file *m, void *v)
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');
......
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