Re: [PATCH 6.12] Revert "sched/core: Reduce cost of sched_move_task when config autogroup"

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 76f970ce51c80f625eb6ddbb24e9cb51b977b598

WARNING: Author mismatch between patch and upstream commit:
Backport author: Hagar Hemdan<hagarhem@amazon.com>
Commit author: Dietmar Eggemann<dietmar.eggemann@arm.com>

Status in newer kernel trees:
6.13.y | Not found

Note: The patch differs from the upstream commit:
---
1:  76f970ce51c80 ! 1:  1382b2427fdda Revert "sched/core: Reduce cost of sched_move_task when config autogroup"
    @@ Metadata
      ## Commit message ##
         Revert "sched/core: Reduce cost of sched_move_task when config autogroup"
     
    +    commit 76f970ce51c80f625eb6ddbb24e9cb51b977b598 upstream.
    +
         This reverts commit eff6c8ce8d4d7faef75f66614dd20bb50595d261.
     
         Hazem reported a 30% drop in UnixBench spawn test with commit
    @@ Commit message
         Tested-by: Hagar Hemdan <hagarhem@amazon.com>
         Cc: Linus Torvalds <torvalds@linux-foundation.org>
         Link: https://lore.kernel.org/r/20250314151345.275739-1-dietmar.eggemann@arm.com
    +    Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
     
      ## kernel/sched/core.c ##
     @@ kernel/sched/core.c: void sched_release_group(struct task_group *tg)
    @@ kernel/sched/core.c: void sched_move_task(struct task_struct *tsk, bool for_auto
     -
      	update_rq_clock(rq);
      
    - 	running = task_current_donor(rq, tsk);
    + 	running = task_current(rq, tsk);
     @@ kernel/sched/core.c: void sched_move_task(struct task_struct *tsk, bool for_autogroup)
      	if (running)
      		put_prev_task(rq, tsk);
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.12.y       |  Success    |  Success   |