[PATCH RFC v7 08/23] dept: Apply sdt_might_sleep_strong() to PG_{locked,writeback} wait

Byungchul Park
2023-01-09T04:05:04Z

Makes Dept able to track dependencies by PG_{locked,writeback} waits.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
mm/filemap.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/mm/filemap.c b/mm/filemap.c
index c4d4ace..b013a5b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -42,6 +42,7 @@
#include <linux/ramfs.h>
#include <linux/page_idle.h>
#include <linux/migrate.h>
+#include <linux/dept_sdt.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include "internal.h"
@@ -1215,6 +1216,9 @@ static inline bool folio_trylock_flag(struct folio *folio, int bit_nr,
/* How many times do we accept lock stealing from under a waiter? */
int sysctl_page_lock_unfairness = 5;

+static struct dept_map __maybe_unused PG_locked_map = DEPT_MAP_INITIALIZER(PG_locked_map, NULL);
+static struct dept_map __maybe_unused PG_writeback_map = DEPT_MAP_INITIALIZER(PG_writeback_map, NULL);
+
static inline int folio_wait_bit_common(struct folio *folio, int bit_nr,
int state, enum behavior behavior)
{
@@ -1226,6 +1230,11 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr,
unsigned long pflags;
bool in_thrashing;

+ if (bit_nr == PG_locked)
+ sdt_might_sleep_strong(&PG_locked_map);
+ else if (bit_nr == PG_writeback)
+ sdt_might_sleep_strong(&PG_writeback_map);
+
if (bit_nr == PG_locked &&
!folio_test_uptodate(folio) && folio_test_workingset(folio)) {
delayacct_thrashing_start(&in_thrashing);
@@ -1327,6 +1336,8 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr,
*/
finish_wait(q, wait);

+ sdt_might_sleep_finish();
+
if (thrashing) {
delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
--
1.9.1