linux-kernel - [PATCH AUTOSEL 6.0 09/32] tools/vm/page_owner

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Message-Id: <20221018000729.2730519-9-sashal@kernel.org>
Date:   Mon, 17 Oct 2022 20:07:06 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Yixuan Cao <caoyixuan2019@...il.szu.edu.cn>,
        Chongxi Zhao <zhaochongxi2019@...il.szu.edu.cn>,
        Jiajian Ye <yejiajian2018@...il.szu.edu.cn>,
        Yuhong Feng <yuhongf@....edu.cn>,
        Liam Mark <lmark@...eaurora.org>,
        Georgi Djakov <georgi.djakov@...aro.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Sasha Levin <sashal@...nel.org>, seanga2@...il.com,
        zhangyinan2019@...il.szu.edu.cn, weizhenliang@...wei.com
Subject: [PATCH AUTOSEL 6.0 09/32] tools/vm/page_owner_sort: fix -f option

From: Yixuan Cao <caoyixuan2019@...il.szu.edu.cn>

[ Upstream commit 57eb60c04d2c7b0de91eac2bc5d0331f8fe72fd7 ]

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@...il.szu.edu.cn>
Cc: Chongxi Zhao <zhaochongxi2019@...il.szu.edu.cn>
Cc: Jiajian Ye <yejiajian2018@...il.szu.edu.cn>
Cc: Yuhong Feng <yuhongf@....edu.cn>
Cc: Liam Mark <lmark@...eaurora.org>
Cc: Georgi Djakov <georgi.djakov@...aro.org>
Cc: Vlastimil Babka <vbabka@...e.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@....com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 tools/vm/page_owner_sort.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/vm/page_owner_sort.c b/tools/vm/page_owner_sort.c
index ec2e67c85b84..ce860ab94162 100644
--- a/tools/vm/page_owner_sort.c
+++ b/tools/vm/page_owner_sort.c
@@ -470,7 +470,12 @@ static bool match_str_list(const char *str, char **list, int list_size)

 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;
-- 
2.35.1