From e1e86503027a00a843a77a0477899e5423c43a59 Mon Sep 17 00:00:00 2001
From: Hongfu Li <lihongfu@kylinos.cn>
Date: Thu, 3 Sep 2026 17:21:26 +0800
Subject: [PATCH] mm/page_owner: preserve original free_pid/free_tgid during
 folio migration

__update_page_owner_free_handle() accepts pid and tgid, but ignores them,
always storing current->pid and current->tgid.

__folio_copy_owner() forwards the original free pid/tgid during folio
migration, yet these values were overwritten by the migrating task.

Store the passed-in pid/tgid so the migrated folio keeps the original free
attribution.

Link: https://lore.kernel.org/20260903092126.24685-1-hongfu.li@linux.dev
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
---
 mm/page_owner.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 3fc37d9b908e..cfc31c92d765 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -307,8 +307,8 @@ static inline void __update_page_owner_free_handle(struct page *page,
 			page_owner->free_handle = handle;
 		}
 		page_owner->free_ts_nsec = free_ts_nsec;
-		page_owner->free_pid = current->pid;
-		page_owner->free_tgid = current->tgid;
+		page_owner->free_pid = pid;
+		page_owner->free_tgid = tgid;
 	}
 	rcu_read_unlock();
 }