The patch titled
Subject: delayacct: support re-entrance detection of thrashing accounting
has been added to the -mm mm-unstable branch. Its filename is
delayacct-support-re-entrance-detection-of-thrashing-accounting.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/delayacct-support-re-entrance-detection-of-thrashing-accounting.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yang Yang <yang.yang29@xxxxxxxxxx>
Subject: delayacct: support re-entrance detection of thrashing accounting
Date: Mon, 15 Aug 2022 07:11:35 +0000
Once upon a time, we only support accounting thrashing of page cache.
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].
For page cache thrashing accounting, there is no suitable place to do it
in fs level likes swap_readpage(). So we have to do it in
folio_wait_bit_common().
Then for anonymous pages thrashing accounting, we have to do it in both
swap_readpage() and folio_wait_bit_common(). This likes PSI, so we should
let thrashing accounting supports re-entrance detection.
This patch is to prepare complete thrashing accounting, and is based on
patch "filemap: make the accounting of thrashing more consistent".
[1] commit aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU")
Link: https://lkml.kernel.org/r/20220815071134.74551-1-yang.yang29@xxxxxxxxxx
Signed-off-by: Yang Yang <yang.yang29@xxxxxxxxxx>
Signed-off-by: CGEL ZTE <cgel.zte@xxxxxxxxx>
Reviewed-by: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
Reviewed-by: wangyong <wang.yong12@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/delayacct.h | 16 ++++++++--------
include/linux/sched.h | 4 ++++
kernel/delayacct.c | 13 +++++++++++--
mm/filemap.c | 10 ++++++----
4 files changed, 29 insertions(+), 14 deletions(-)
--- a/include/linux/delayacct.h~delayacct-support-re-entrance-detection-of-thrashing-accounting
+++ a/include/linux/delayacct.h
@@ -73,8 +73,8 @@ extern int delayacct_add_tsk(struct task
extern __u64 __delayacct_blkio_ticks(struct task_struct *);
extern void __delayacct_freepages_start(void);
extern void __delayacct_freepages_end(void);
-extern void __delayacct_thrashing_start(void);
-extern void __delayacct_thrashing_end(void);
+extern void __delayacct_thrashing_start(bool *in_thrashing);
+extern void __delayacct_thrashing_end(bool *in_thrashing);
extern void __delayacct_swapin_start(void);
extern void __delayacct_swapin_end(void);
extern void __delayacct_compact_start(void);
@@ -143,22 +143,22 @@ static inline void delayacct_freepages_e
__delayacct_freepages_end();
}
-static inline void delayacct_thrashing_start(void)
+static inline void delayacct_thrashing_start(bool *in_thrashing)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
- __delayacct_thrashing_start();
+ __delayacct_thrashing_start(in_thrashing);
}
-static inline void delayacct_thrashing_end(void)
+static inline void delayacct_thrashing_end(bool *in_thrashing)
{
if (!static_branch_unlikely(&delayacct_key))
return;
if (current->delays)
- __delayacct_thrashing_end();
+ __delayacct_thrashing_end(in_thrashing);
}
static inline void delayacct_swapin_start(void)
@@ -237,9 +237,9 @@ static inline void delayacct_freepages_s
{}
static inline void delayacct_freepages_end(void)
{}
-static inline void delayacct_thrashing_start(void)
+static inline void delayacct_thrashing_start(bool *in_thrashing)
{}
-static inline void delayacct_thrashing_end(void)
+static inline void delayacct_thrashing_end(bool *in_thrashing)
{}
static inline void delayacct_swapin_start(void)
{}
--- a/include/linux/sched.h~delayacct-support-re-entrance-detection-of-thrashing-accounting
+++ a/include/linux/sched.h
@@ -948,6 +948,10 @@ struct task_struct {
#ifdef CONFIG_CPU_SUP_INTEL
unsigned reported_split_lock:1;
#endif
+#ifdef CONFIG_TASK_DELAY_ACCT
+ /* delay due to memory thrashing */
+ unsigned in_thrashing:1;
+#endif
unsigned long atomic_flags; /* Flags requiring atomic access. */
--- a/kernel/delayacct.c~delayacct-support-re-entrance-detection-of-thrashing-accounting
+++ a/kernel/delayacct.c
@@ -214,13 +214,22 @@ void __delayacct_freepages_end(void)
¤t->delays->freepages_count);
}
-void __delayacct_thrashing_start(void)
+void __delayacct_thrashing_start(bool *in_thrashing)
{
+ *in_thrashing = !!current->in_thrashing;
+ if (*in_thrashing)
+ return;
+
+ current->in_thrashing = 1;
current->delays->thrashing_start = local_clock();
}
-void __delayacct_thrashing_end(void)
+void __delayacct_thrashing_end(bool *in_thrashing)
{
+ if (*in_thrashing)
+ return;
+
+ current->in_thrashing = 0;
delayacct_end(¤t->delays->lock,
¤t->delays->thrashing_start,
¤t->delays->thrashing_delay,
--- a/mm/filemap.c~delayacct-support-re-entrance-detection-of-thrashing-accounting
+++ a/mm/filemap.c
@@ -1222,10 +1222,11 @@ static inline int folio_wait_bit_common(
wait_queue_entry_t *wait = &wait_page.wait;
bool thrashing = false;
unsigned long pflags;
+ bool in_thrashing;
if (bit_nr == PG_locked &&
!folio_test_uptodate(folio) && folio_test_workingset(folio)) {
- delayacct_thrashing_start();
+ delayacct_thrashing_start(&in_thrashing);
psi_memstall_enter(&pflags);
thrashing = true;
}
@@ -1325,7 +1326,7 @@ repeat:
finish_wait(q, wait);
if (thrashing) {
- delayacct_thrashing_end();
+ delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
}
@@ -1374,12 +1375,13 @@ void migration_entry_wait_on_locked(swp_
wait_queue_entry_t *wait = &wait_page.wait;
bool thrashing = false;
unsigned long pflags;
+ bool in_thrashing;
wait_queue_head_t *q;
struct folio *folio = page_folio(pfn_swap_entry_to_page(entry));
q = folio_waitqueue(folio);
if (!folio_test_uptodate(folio) && folio_test_workingset(folio)) {
- delayacct_thrashing_start();
+ delayacct_thrashing_start(&in_thrashing);
psi_memstall_enter(&pflags);
thrashing = true;
}
@@ -1426,7 +1428,7 @@ void migration_entry_wait_on_locked(swp_
finish_wait(q, wait);
if (thrashing) {
- delayacct_thrashing_end();
+ delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
}
}
_
Patches currently in -mm which might be from yang.yang29@xxxxxxxxxx are
mm-vmscan-define-macros-for-refaults-in-struct-lruvec.patch
filemap-make-the-accounting-of-thrashing-more-consistent.patch
mm-vmscan-make-the-annotations-of-refaults-code-at-the-right-place.patch
delayacct-support-re-entrance-detection-of-thrashing-accounting.patch
mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch
