2020-06-24 15:03:09

by Naoya Horiguchi

Subject: [PATCH v3 02/15] mm, hwpoison: remove recalculating hpage

From: Naoya Horiguchi <[email protected]>

hpage is never used after try_to_split_thp_page() in memory_failure(),
so we don't have to update hpage. So let's not recalculate/use hpage.

Suggested-by: "Aneesh Kumar K.V" <[email protected]>
Signed-off-by: Naoya Horiguchi <[email protected]>
---
mm/memory-failure.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c
index e5d0c14c2332..d2d6010764e7 100644
--- v5.8-rc1-mmots-2020-06-20-21-44/mm/memory-failure.c
+++ v5.8-rc1-mmots-2020-06-20-21-44_patched/mm/memory-failure.c
@@ -1342,7 +1342,6 @@ int memory_failure(unsigned long pfn, int flags)
}
unlock_page(p);
VM_BUG_ON_PAGE(!page_count(p), p);
- hpage = compound_head(p);
}

/*
@@ -1414,11 +1413,8 @@ int memory_failure(unsigned long pfn, int flags)
/*
* Now take care of user space mappings.
* Abort on fail: __delete_from_page_cache() assumes unmapped page.
- *
- * When the raw error page is thp tail page, hpage points to the raw
- * page after thp split.
*/
- if (!hwpoison_user_mappings(p, pfn, flags, &hpage)) {
+ if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
res = -EBUSY;
goto out;
--
2.17.1

2020-06-30 23:46:34

by Mike Kravetz

Subject: Re: [PATCH v3 02/15] mm, hwpoison: remove recalculating hpage

On 6/24/20 8:01 AM, [email protected] wrote:
> From: Naoya Horiguchi <[email protected]>
>
> hpage is never used after try_to_split_thp_page() in memory_failure(),
> so we don't have to update hpage. So let's not recalculate/use hpage.
>
> Suggested-by: "Aneesh Kumar K.V" <[email protected]>
> Signed-off-by: Naoya Horiguchi <[email protected]>

Reviewed-by: Mike Kravetz <[email protected]>
--
Mike Kravetz