From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Note the number of pages currently used in page_frag allocations.
This may help diagnose leaks in page_frag users.
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
include/linux/mmzone.h | 3 ++-
mm/page_alloc.c | 10 +++++++---
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7522a6987595..ed6be33dcc7a 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -139,10 +139,10 @@ enum zone_stat_item {
NR_ZONE_ACTIVE_FILE,
NR_ZONE_UNEVICTABLE,
NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
+ /* Second 128 byte cacheline */
NR_MLOCK, /* mlock()ed pages found and moved off LRU */
NR_PAGETABLE, /* used for pagetables */
NR_KERNEL_STACK_KB, /* measured in KiB */
- /* Second 128 byte cacheline */
NR_BOUNCE,
#if IS_ENABLED(CONFIG_ZSMALLOC)
NR_ZSPAGES, /* allocated in zsmalloc */
@@ -175,6 +175,7 @@ enum node_stat_item {
NR_SHMEM_THPS,
NR_SHMEM_PMDMAPPED,
NR_ANON_THPS,
+ NR_PAGE_FRAG,
NR_UNSTABLE_NFS, /* NFS unstable pages */
NR_VMSCAN_WRITE,
NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b9beafa5d2a5..5a9441b46604 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4382,6 +4382,7 @@ static void *__page_frag_cache_refill(struct page_frag_cache *pfc,
return NULL;
}
+ inc_node_page_state(page, NR_PAGE_FRAG);
/* Using atomic_set() would break get_page_unless_zero() users. */
page_ref_add(page, size - 1);
reset:
@@ -4460,8 +4461,10 @@ void page_frag_free(void *addr)
{
struct page *page = virt_to_head_page(addr);
- if (unlikely(put_page_testzero(page)))
+ if (unlikely(put_page_testzero(page))) {
+ dec_node_page_state(page, NR_PAGE_FRAG);
__free_pages_ok(page, compound_order(page));
+ }
}
EXPORT_SYMBOL(page_frag_free);
@@ -4769,7 +4772,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
" unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
" slab_reclaimable:%lu slab_unreclaimable:%lu\n"
" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
- " free:%lu free_pcp:%lu free_cma:%lu\n",
+ " free:%lu free_pcp:%lu free_cma:%lu page_frag:%lu\n",
global_node_page_state(NR_ACTIVE_ANON),
global_node_page_state(NR_INACTIVE_ANON),
global_node_page_state(NR_ISOLATED_ANON),
@@ -4788,7 +4791,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
global_zone_page_state(NR_BOUNCE),
global_zone_page_state(NR_FREE_PAGES),
free_pcp,
- global_zone_page_state(NR_FREE_CMA_PAGES));
+ global_zone_page_state(NR_FREE_CMA_PAGES),
+ global_node_page_state(NR_PAGE_FRAG));
for_each_online_pgdat(pgdat) {
if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
--
2.16.2
