[RFC PATCH 4/5] mm: rename and change semantics of nr_indirectly_reclaimable_bytes
From: Vlastimil Babka <hidden>
Date: 2018-05-24 11:01:35
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - core, memory management - mglru (multi-gen lru), memory management - page allocator, staging subsystem, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Greg Kroah-Hartman, Linus Torvalds
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by commit
eb59254608bc ("mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES") with the goal of
accounting objects that can be reclaimed, but cannot be allocated via a
SLAB_RECLAIM_ACCOUNT cache. This is now possible via kmalloc() with
__GFP_RECLAIMABLE flag, and the dcache external names user is converted.
The counter is however still useful for accounting direct page allocations
(i.e. not slab) with a shrinker, such as the ION page pool. So keep it, and:
- change granularity to pages to be more like other counters; sub-page
allocations should be able to use kmalloc
- rename the counter to NR_RECLAIMABLE
- expose the counter again in vmstat as "nr_reclaimable"; we can again remove
the check for not printing "hidden" counters
- make the counter include also SLAB_RECLAIM_ACCOUNT, so it covers all
shrinker-based (i.e. not page cache) reclaimable pages
Signed-off-by: Vlastimil Babka <redacted>
---
drivers/staging/android/ion/ion_page_pool.c | 4 ++--
include/linux/mmzone.h | 2 +-
mm/page_alloc.c | 15 ++++-----------
mm/slab.c | 12 ++++++++----
mm/util.c | 16 +++++-----------
mm/vmstat.c | 6 +-----
6 files changed, 21 insertions(+), 34 deletions(-)
diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
index 9bc56eb48d2a..11e6e694f425 100644
--- a/drivers/staging/android/ion/ion_page_pool.c
+++ b/drivers/staging/android/ion/ion_page_pool.c@@ -33,8 +33,8 @@ static void ion_page_pool_add(struct ion_page_pool *pool, struct page *page) pool->low_count++; } - mod_node_page_state(page_pgdat(page), NR_INDIRECTLY_RECLAIMABLE_BYTES, - (1 << (PAGE_SHIFT + pool->order))); + mod_node_page_state(page_pgdat(page), NR_RECLAIMABLE, + 1 << pool->order); mutex_unlock(&pool->mutex); }
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 32699b2dc52a..4343948f33e5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h@@ -180,7 +180,7 @@ enum node_stat_item { NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ NR_DIRTIED, /* page dirtyings since bootup */ NR_WRITTEN, /* page writings since bootup */ - NR_INDIRECTLY_RECLAIMABLE_BYTES, /* measured in bytes */ + NR_RECLAIMABLE, /* all reclaimable pages, including slab */ NR_VM_NODE_STAT_ITEMS };
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 249546393bd6..6f22fec0df54 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -4708,6 +4708,7 @@ long si_mem_available(void) unsigned long pagecache; unsigned long wmark_low = 0; unsigned long pages[NR_LRU_LISTS]; + unsigned long reclaimable; struct zone *zone; int lru;
@@ -4733,19 +4734,11 @@ long si_mem_available(void) available += pagecache; /* - * Part of the reclaimable slab consists of items that are in use, + * Part of the reclaimable pages consists of items that are in use, * and cannot be freed. Cap this estimate at the low watermark. */ - available += global_node_page_state(NR_SLAB_RECLAIMABLE) - - min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2, - wmark_low); - - /* - * Part of the kernel memory, which can be released under memory - * pressure. - */ - available += global_node_page_state(NR_INDIRECTLY_RECLAIMABLE_BYTES) >> - PAGE_SHIFT; + reclaimable = global_node_page_state(NR_RECLAIMABLE); + available += reclaimable - min(reclaimable / 2, wmark_low); if (available < 0) available = 0;
diff --git a/mm/slab.c b/mm/slab.c
index 4dd7d73a1972..a2a8c0802253 100644
--- a/mm/slab.c
+++ b/mm/slab.c@@ -1420,10 +1420,12 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, } nr_pages = (1 << cachep->gfporder); - if (cachep->flags & SLAB_RECLAIM_ACCOUNT) + if (cachep->flags & SLAB_RECLAIM_ACCOUNT) { mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages); - else + mod_node_page_state(page_pgdat(page), NR_RECLAIMABLE, nr_pages); + } else { mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages); + } __SetPageSlab(page); /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
@@ -1441,10 +1443,12 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page) int order = cachep->gfporder; unsigned long nr_freed = (1 << order); - if (cachep->flags & SLAB_RECLAIM_ACCOUNT) + if (cachep->flags & SLAB_RECLAIM_ACCOUNT) { mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed); - else + mod_node_page_state(page_pgdat(page), NR_RECLAIMABLE, -nr_freed); + } else { mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed); + } BUG_ON(!PageSlab(page)); __ClearPageSlabPfmemalloc(page);
diff --git a/mm/util.c b/mm/util.c
index 98180a994895..3ffd92a9778a 100644
--- a/mm/util.c
+++ b/mm/util.c@@ -662,19 +662,13 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) free += get_nr_swap_pages(); /* - * Any slabs which are created with the + * Pages accounted as reclaimable. + * This includes any slabs which are created with the * SLAB_RECLAIM_ACCOUNT flag claim to have contents - * which are reclaimable, under pressure. The dentry - * cache and most inode caches should fall into this + * which are reclaimable, under pressure. The dentry + * cache and most inode caches should fall into this. */ - free += global_node_page_state(NR_SLAB_RECLAIMABLE); - - /* - * Part of the kernel memory, which can be released - * under memory pressure. - */ - free += global_node_page_state( - NR_INDIRECTLY_RECLAIMABLE_BYTES) >> PAGE_SHIFT; + free += global_node_page_state(NR_RECLAIMABLE); /* * Leave reserved pages. The pages are not for anonymous pages.
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 75eda9c2b260..21d571da9d5a 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c@@ -1161,7 +1161,7 @@ const char * const vmstat_text[] = { "nr_vmscan_immediate_reclaim", "nr_dirtied", "nr_written", - "", /* nr_indirectly_reclaimable */ + "nr_reclaimable", /* enum writeback_stat_item counters */ "nr_dirty_threshold",
@@ -1704,10 +1704,6 @@ static int vmstat_show(struct seq_file *m, void *arg) unsigned long *l = arg; unsigned long off = l - (unsigned long *)m->private; - /* Skip hidden vmstat items. */ - if (*vmstat_text[off] == '\0') - return 0; - seq_puts(m, vmstat_text[off]); seq_put_decimal_ull(m, " ", *l); seq_putc(m, '\n');
--
2.17.0