2024-05-17 01:36:19

by chenridong

Subject: [PATCH -next] cgroup/pids: remove pids_cancel_attach

In pids subsystem, pids_can_attach never returns an error.
Therefore, pids_cancel_attach is unnecessary and is never called.
As a result, it should be removed.

Signed-off-by: Chen Ridong <[email protected]>
---
kernel/cgroup/pids.c | 19 -------------------
1 file changed, 19 deletions(-)

diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index 0e5ec7d59b4d..a7a719495547 100644
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -211,24 +211,6 @@ static int pids_can_attach(struct cgroup_taskset *tset)
return 0;
}

-static void pids_cancel_attach(struct cgroup_taskset *tset)
-{
- struct task_struct *task;
- struct cgroup_subsys_state *dst_css;
-
- cgroup_taskset_for_each(task, dst_css, tset) {
- struct pids_cgroup *pids = css_pids(dst_css);
- struct cgroup_subsys_state *old_css;
- struct pids_cgroup *old_pids;
-
- old_css = task_css(task, pids_cgrp_id);
- old_pids = css_pids(old_css);
-
- pids_charge(old_pids, 1);
- pids_uncharge(pids, 1);
- }
-}
-
/*
* task_css_check(true) in pids_can_fork() and pids_cancel_fork() relies
* on cgroup_threadgroup_change_begin() held by the copy_process().
@@ -375,7 +357,6 @@ struct cgroup_subsys pids_cgrp_subsys = {
.css_alloc = pids_css_alloc,
.css_free = pids_css_free,
.can_attach = pids_can_attach,
- .cancel_attach = pids_cancel_attach,
.can_fork = pids_can_fork,
.cancel_fork = pids_cancel_fork,
.release = pids_release,
--
2.34.1

2024-05-17 01:47:37

by Tejun Heo

Subject: Re: [PATCH -next] cgroup/pids: remove pids_cancel_attach

On Fri, May 17, 2024 at 01:30:01AM +0000, Chen Ridong wrote:
> In pids subsystem, pids_can_attach never returns an error.
> Therefore, pids_cancel_attach is unnecessary and is never called.
> As a result, it should be removed.

There are subsystems which can tho and if pids is being migrated together,
its cancel will be called.

Thanks.

--
tejun

2024-05-17 01:56:20

by chenridong

Subject: 答复: [PATCH -next] cgroup/pids: remove pids_ cancel_attach

See, thank you.

-----?ʼ?ԭ??-----
??????: Tejun Heo <[email protected]> ???? Tejun Heo
????ʱ??: 2024??5??17?? 9:46
?ռ???: chenridong <[email protected]>
????: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
????: Re: [PATCH -next] cgroup/pids: remove pids_cancel_attach

On Fri, May 17, 2024 at 01:30:01AM +0000, Chen Ridong wrote:
> In pids subsystem, pids_can_attach never returns an error.
> Therefore, pids_cancel_attach is unnecessary and is never called.
> As a result, it should be removed.

There are subsystems which can tho and if pids is being migrated together, its cancel will be called.

Thanks.

--
tejun