We are going to add MADV_FREE pages into a new LRU list. Add a new flag
to indicate such pages. Note, we are reusing PG_mappedtodisk for the new
flag. This is ok because no anonymous pages have this flag set.
The patch is based on Minchan's previous patch.
Cc: Michal Hocko <mho...@suse.com>
Cc: Minchan Kim <minc...@kernel.org>
Cc: Hugh Dickins <hu...@google.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Rik van Riel <r...@redhat.com>
Cc: Mel Gorman <mgor...@techsingularity.net>
Signed-off-by: Shaohua Li<s...@fb.com>
---
fs/proc/task_mmu.c | 8 +++++++-
include/linux/mm_inline.h | 5 +++++
include/linux/page-flags.h | 6 ++++++
mm/huge_memory.c | 1 +
mm/migrate.c | 2 ++
5 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ee3efb2..813d3aa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -440,6 +440,7 @@ struct mem_size_stats {
unsigned long private_dirty;
unsigned long referenced;
unsigned long anonymous;
+ unsigned long lazyfree;
unsigned long anonymous_thp;
unsigned long shmem_thp;
unsigned long swap;
@@ -456,8 +457,11 @@ static void smaps_account(struct mem_size_stats *mss,
struct page *page,
int i, nr = compound ? 1 << compound_order(page) : 1;
unsigned long size = nr * PAGE_SIZE;
- if (PageAnon(page))
+ if (PageAnon(page)) {
mss->anonymous += size;
+ if (PageLazyFree(page))
+ mss->lazyfree += size;
+ }
mss->resident += size;
/* Accumulate the size in pages that have been accessed. */
@@ -770,6 +774,7 @@ static int show_smap(struct seq_file *m, void *v, int
is_pid)
"Private_Dirty: %8lu kB\n"
"Referenced: %8lu kB\n"
"Anonymous: %8lu kB\n"
+ "LazyFree: %8lu kB\n"
"AnonHugePages: %8lu kB\n"
"ShmemPmdMapped: %8lu kB\n"
"Shared_Hugetlb: %8lu kB\n"
@@ -788,6 +793,7 @@ static int show_smap(struct seq_file *m, void *v, int
is_pid)
mss.private_dirty >> 10,
mss.referenced >> 10,
mss.anonymous >> 10,
+ mss.lazyfree >> 10,
mss.anonymous_thp >> 10,
mss.shmem_thp >> 10,
mss.shared_hugetlb >> 10,
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 0dddc2c..828e813 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -22,6 +22,11 @@ static inline int page_is_file_cache(struct page *page)
return !PageSwapBacked(page);
}
+static inline bool page_is_lazyfree(struct page *page)
+{
+ return PageSwapBacked(page) && PageLazyFree(page);
+}
+
static __always_inline void __update_lru_size(struct lruvec *lruvec,
enum lru_list lru, enum zone_type zid,
int nr_pages)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 6b5818d..e8ea378 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -107,6 +107,9 @@ enum pageflags {
#endif
__NR_PAGEFLAGS,
+ /* MADV_FREE */
+ PG_lazyfree = PG_mappedtodisk,
+
/* Filesystems */
PG_checked = PG_owner_priv_1,
@@ -428,6 +431,9 @@ TESTPAGEFLAG_FALSE(Ksm)
u64 stable_page_flags(struct page *page);
+PAGEFLAG(LazyFree, lazyfree, PF_ANY)
+ __CLEARPAGEFLAG(LazyFree, lazyfree, PF_ANY)
+
static inline int PageUptodate(struct page *page)
{
int ret;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 40bd376..ffa7ed5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1918,6 +1918,7 @@ static void __split_huge_page_tail(struct page *head, int
tail,
(1L << PG_swapbacked) |
(1L << PG_mlocked) |
(1L << PG_uptodate) |
+ (1L << PG_lazyfree) |
(1L << PG_active) |
(1L << PG_locked) |
(1L << PG_unevictable) |
diff --git a/mm/migrate.c b/mm/migrate.c
index 502ebea..496105c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -641,6 +641,8 @@ void migrate_page_copy(struct page *newpage, struct page
*page)
SetPageChecked(newpage);
if (PageMappedToDisk(page))
SetPageMappedToDisk(newpage);
+ if (PageLazyFree(page))
+ SetPageLazyFree(newpage);
/* Move dirty on pages not done by migrate_page_move_mapping() */
if (PageDirty(page))
--
2.9.3
