+ tools-vm-page_owner_sort-fix-f-option.patch added to mm-unstable branch

+ tools-vm-page_owner_sort-fix-f-option.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: tools/vm/page_owner_sort: fix -f option
has been added to the -mm mm-unstable branch.  Its filename is
     tools-vm-page_owner_sort-fix-f-option.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/tools-vm-page_owner_sort-fix-f-option.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: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Subject: tools/vm/page_owner_sort: fix -f option
Date: Fri, 12 Aug 2022 23:55:15 +0800

The -f option is to filter out the information of blocks whose memory has
not been released, I noticed some blocks should not be filtered out.

Commit 9cc7e96aa846 ("mm/page_owner: record timestamp and pid") records
the allocation timestamp (ts_nsec) of all pages.

Commit 866b48526217 ("mm/page_owner: record the timestamp of all pages
during free") records the free timestamp (free_ts_nsec) of all pages. 
When the page is allocated for the first time, the initial value of
free_ts_nsec is 0, and the corresponding time will be obtained when the
page is released.  But during reallocation the free_ts_nsec will not reset
to 0 again.  In particular, when page migration occurs, these two
timestamps will be the same.

Now page_owner_sort removes all text blocks whose free_ts_nsec is not 0
when using -f option.  However, this way can only select pages allocated
for the first time.  If a freed page is reallocated, free_ts_nsec will be
less than ts_nsec; if page migration occurs, the two timestamps will be
equal.  These cases should be considered as pages are not released.

So I fix the function is_need() to keep text blocks that meet the above
two conditions when using -f option.

Link: https://lkml.kernel.org/r/20220812155515.30846-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn>
Cc: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Yuhong Feng <yuhongf@szu.edu.cn>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/vm/page_owner_sort.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/tools/vm/page_owner_sort.c~tools-vm-page_owner_sort-fix-f-option
+++ a/tools/vm/page_owner_sort.c
@@ -470,7 +470,12 @@ static bool match_str_list(const char *s
 
 static bool is_need(char *buf)
 {
-	if ((filter & FILTER_UNRELEASE) && get_free_ts_nsec(buf) != 0)
+	__u64 ts_nsec, free_ts_nsec;
+
+	ts_nsec = get_ts_nsec(buf);
+	free_ts_nsec = get_free_ts_nsec(buf);
+
+	if ((filter & FILTER_UNRELEASE) && free_ts_nsec != 0 && ts_nsec < free_ts_nsec)
 		return false;
 	if ((filter & FILTER_PID) && !match_num_list(get_pid(buf), fc.pids, fc.pids_size))
 		return false;
_

Patches currently in -mm which might be from caoyixuan2019@email.szu.edu.cn are

tools-vm-page_owner_sort-fix-f-option.patch