[PATCH v2] mm: memory-failure: cleanup try_to_split_thp_page()

[PATCH v2] mm: memory-failure: cleanup try_to_split_thp_page()

[Kefeng Wang]

Since commit 5d1fd5dc877b ("mm,hwpoison: introduce MF_MSG_UNSPLIT_THP"),
the action_result(,MF_MSG_UNSPLIT_THP,) called to show memory error event
in memory_failure(), so the pr_info() in try_to_split_thp_page() is only
needed in soft_offline_in_use_page().

Meanwhile this could also fix the unexpected prefix for "thp split failed"
due to commit 96f96763de26 ("mm: memory-failure: convert to pr_fmt()").

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
v2: update changelog

 mm/memory-failure.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 14439806b5ef..0dfed9d7b273 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1524,20 +1524,18 @@ static int identify_page_state(unsigned long pfn, struct page *p,
 	return page_action(ps, p, pfn);
 }
 
-static int try_to_split_thp_page(struct page *page, const char *msg)
+static int try_to_split_thp_page(struct page *page)
 {
+	int ret;
+
 	lock_page(page);
-	if (unlikely(split_huge_page(page))) {
-		unsigned long pfn = page_to_pfn(page);
+	ret = split_huge_page(page);
+	unlock_page(page);
 
-		unlock_page(page);
-		pr_info("%s: %#lx: thp split failed\n", msg, pfn);
+	if (unlikely(ret))
 		put_page(page);
-		return -EBUSY;
-	}
-	unlock_page(page);
 
-	return 0;
+	return ret;
 }
 
 static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn,
@@ -2079,7 +2077,7 @@ int memory_failure(unsigned long pfn, int flags)
 		 * page is a valid handlable page.
 		 */
 		SetPageHasHWPoisoned(hpage);
-		if (try_to_split_thp_page(p, "Memory Failure") < 0) {
+		if (try_to_split_thp_page(p) < 0) {
 			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
 			res = -EBUSY;
 			goto unlock_mutex;
@@ -2505,8 +2503,11 @@ static int soft_offline_in_use_page(struct page *page)
 	struct page *hpage = compound_head(page);
 
 	if (!PageHuge(page) && PageTransHuge(hpage))
-		if (try_to_split_thp_page(page, "soft offline") < 0)
+		if (try_to_split_thp_page(page) < 0) {
+			pr_info("soft offline: %#lx: thp split failed\n",
+				page_to_pfn(page));
 			return -EBUSY;
+		}
 	return __soft_offline_page(page);
 }
 
-- 
2.35.3

Re: [PATCH v2] mm: memory-failure: cleanup try_to_split_thp_page()

[HORIGUCHI NAOYA(堀口 直也)]

On Tue, Aug 09, 2022 at 07:18:13PM +0800, Kefeng Wang wrote:
> Since commit 5d1fd5dc877b ("mm,hwpoison: introduce MF_MSG_UNSPLIT_THP"),
> the action_result(,MF_MSG_UNSPLIT_THP,) called to show memory error event
> in memory_failure(), so the pr_info() in try_to_split_thp_page() is only
> needed in soft_offline_in_use_page().
> 
> Meanwhile this could also fix the unexpected prefix for "thp split failed"
> due to commit 96f96763de26 ("mm: memory-failure: convert to pr_fmt()").
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

# Sorry for my late reply, I'm back from summer holiday...

Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>

Re: [PATCH v2] mm: memory-failure: cleanup try_to_split_thp_page()

[Kefeng Wang]

On 2022/8/16 13:47, HORIGUCHI NAOYA(堀口 直也) wrote:
> On Tue, Aug 09, 2022 at 07:18:13PM +0800, Kefeng Wang wrote:
>> Since commit 5d1fd5dc877b ("mm,hwpoison: introduce MF_MSG_UNSPLIT_THP"),
>> the action_result(,MF_MSG_UNSPLIT_THP,) called to show memory error event
>> in memory_failure(), so the pr_info() in try_to_split_thp_page() is only
>> needed in soft_offline_in_use_page().
>>
>> Meanwhile this could also fix the unexpected prefix for "thp split failed"
>> due to commit 96f96763de26 ("mm: memory-failure: convert to pr_fmt()").
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> # Sorry for my late reply, I'm back from summer holiday...
>
> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Thanks Noaya.