Re: [PATCH 5.4.y v2] epoll: Add synchronous wakeup support for ep_poll_callback

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Found matching upstream commit: 900bbaae67e980945dec74d36f8afe0de7556d5a

WARNING: Author mismatch between patch and found commit:
Backport author: Wenshan Lan <jetlan9@163.com>
Commit author: Xuewen Yan <xuewen.yan@unisoc.com>


Status in newer kernel trees:
6.12.y | Not found
6.6.y | Not found
6.1.y | Not found
5.15.y | Not found
5.10.y | Not found
5.4.y | Not found

Note: The patch differs from the upstream commit:
---
1:  900bbaae67e9 ! 1:  b90bb7104c43 epoll: Add synchronous wakeup support for ep_poll_callback
    @@ Commit message
         Reviewed-by: Brian Geffon <bgeffon@google.com>
         Reported-by: Benoit Lize <lizeb@google.com>
         Signed-off-by: Christian Brauner <brauner@kernel.org>
    +    (cherry picked from commit 900bbaae67e980945dec74d36f8afe0de7556d5a)
    +    [ Redefine wake_up_sync(x) as __wake_up_sync(x, TASK_NORMAL, 1) to
    +      make it work on 5.4.y ]
    +    Signed-off-by: Wenshan Lan <jetlan9@163.com>
     
      ## fs/eventpoll.c ##
     @@ fs/eventpoll.c: static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v
    @@ include/linux/wait.h: void __wake_up_pollfree(struct wait_queue_head *wq_head);
      #define wake_up_all(x)			__wake_up(x, TASK_NORMAL, 0, NULL)
      #define wake_up_locked(x)		__wake_up_locked((x), TASK_NORMAL, 1)
      #define wake_up_all_locked(x)		__wake_up_locked((x), TASK_NORMAL, 0)
    -+#define wake_up_sync(x)			__wake_up_sync(x, TASK_NORMAL)
    ++#define wake_up_sync(x)			__wake_up_sync(x, TASK_NORMAL, 1)
      
      #define wake_up_interruptible(x)	__wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
      #define wake_up_interruptible_nr(x, nr)	__wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Success    |  Success   |