From: Yang Yang <yang.yang29@xxxxxxxxxx>
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].
Likes PSI, we count submission time as thrashing delay because when
the device is congested, or the submitting cgroup IO-throttled,
submission can be a significant part of overall IO time.
This patch is based on "delayacct: support re-entrance detection of
thrashing accounting".
[1] commit aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU")
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>
---
Change for v2:
- use bool in_thrashing instead of unsigned long dflags
---
mm/page_io.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/mm/page_io.c b/mm/page_io.c
index 68318134dc92..653a2adcfdd9 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -453,18 +453,21 @@ int swap_readpage(struct page *page, bool synchronous,
struct swap_info_struct *sis = page_swap_info(page);
bool workingset = PageWorkingset(page);
unsigned long pflags;
+ bool in_thrashing;
VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageUptodate(page), page);
/*
- * Count submission time as memory stall. When the device is congested,
- * or the submitting cgroup IO-throttled, submission can be a
- * significant part of overall IO time.
+ * Count submission time as memory stall and delay. When the device
+ * is congested, or the submitting cgroup IO-throttled, submission
+ * can be a significant part of overall IO time.
*/
- if (workingset)
+ if (workingset) {
+ delayacct_thrashing_start(&in_thrashing);
psi_memstall_enter(&pflags);
+ }
delayacct_swapin_start();
if (frontswap_load(page) == 0) {
@@ -513,8 +516,10 @@ int swap_readpage(struct page *page, bool synchronous,
bio_put(bio);
out:
- if (workingset)
+ if (workingset) {
+ delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
+ }
delayacct_swapin_end();
return ret;
}
--
2.25.1
