Re: [PATCH v4 0/3] mm/khugepaged: fix khugepaged+shmem races
From: Miko Larsson
Date: Fri Feb 17 2023 - 05:37:28 EST
On Fri, 2023-02-17 at 17:54 +0900, David Stevens wrote:
> From: David Stevens <stevensd@xxxxxxxxxxxx>
>
> Fix two races in khugepaged+shmem that cause issues with userfaultfd
> and
> lseek, respectively.
>
> v3 -> v4:
> - Base changes on mm-everything (fba720cb4dc0)
> - Add patch to refactor error handling control flow in collapse_file
> - Rebase userfaultfd patch with no significant logic changes
> - Different approach for fixing lseek race
> v2 -> v3:
> - Use XA_RETRY_ENTRY to synchronize with reads from the page cache
> under the RCU read lock in userfaultfd fix
> - Add patch to fix lseek race
> v1 -> v2:
> - Different approach for userfaultfd fix
>
> David Stevens (3):
> mm/khugepaged: refactor collapse_file control flow
> mm/khugepaged: skip shmem with userfaultfd
> mm/khugepaged: maintain page cache uptodate flag
>
> include/trace/events/huge_memory.h | 3 +-
> mm/khugepaged.c | 263 ++++++++++++++++-----------
> --
> 2 files changed, 144 insertions(+), 122 deletions(-)
>
Might want to Cc this to the stable mailing list.
--
~miko