* 5.18 missing /proc/sys/kernel/sched_autogroup_enabled?
@ 2022-05-29 23:52 Ivan Kozik
2022-05-30 7:45 ` Peter Zijlstra
0 siblings, 1 reply; 4+ messages in thread
From: Ivan Kozik @ 2022-05-29 23:52 UTC (permalink / raw)
To: linux-kernel; +Cc: nizhen, peterz, mingo
Hello,
I noticed that /proc/sys/kernel/sched_autogroup_enabled seems to have
gone missing in 5.18. Am I doing something wrong, or is this a
regression?
I also noticed that booting 5.18 with "noautogroup" results in a
"kernel: failed when register_sysctl sched_autogroup_sysctls to
kernel" message. Because of the error and the missing
/proc/sys/kernel/sched_autogroup_enabled, it is unclear whether
autogroup is enabled or not.
Please see below for my testing. These kernels came from
https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.18/ but I saw the
same thing with a 5.18.0 on NixOS.
Best regards,
Ivan
5.17, default:
at@ubuntu2204:~$ uname -a
Linux ubuntu2204 5.17.11-051711-generic #202205251331 SMP PREEMPT Wed
May 25 13:57:33 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
at@ubuntu2204:~$ journalctl -b | grep -i autogroup
at@ubuntu2204:~$ cat /proc/sys/kernel/sched_autogroup_enabled
1
5.17, noautogroup:
at@ubuntu2204:~$ uname -a
Linux ubuntu2204 5.17.11-051711-generic #202205251331 SMP PREEMPT Wed
May 25 13:57:33 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
at@ubuntu2204:~$ journalctl -b | grep -i autogroup
May 29 15:58:17 ubuntu2204 kernel: Command line:
BOOT_IMAGE=/boot/vmlinuz-5.17.11-051711-generic
root=UUID=20672a55-02fc-49b3-8c04-bd040f068096 ro
find_preseed=/preseed.cfg auto noprompt priority=critical locale=en_US
quiet splash noautogroup
May 29 15:58:17 ubuntu2204 kernel: Kernel command line:
BOOT_IMAGE=/boot/vmlinuz-5.17.11-051711-generic
root=UUID=20672a55-02fc-49b3-8c04-bd040f068096 ro
find_preseed=/preseed.cfg auto noprompt priority=critical locale=en_US
quiet splash noautogroup
at@ubuntu2204:~$ cat /proc/sys/kernel/sched_autogroup_enabled
0
5.18, default:
at@ubuntu2204:~$ uname -a
Linux ubuntu2204 5.18.0-051800-generic #202205222030 SMP
PREEMPT_DYNAMIC Sun May 22 20:33:46 UTC 2022 x86_64 x86_64 x86_64
GNU/Linux
at@ubuntu2204:~$ journalctl -b | grep -i autogroup
at@ubuntu2204:~$ cat /proc/sys/kernel/sched_autogroup_enabled
cat: /proc/sys/kernel/sched_autogroup_enabled: No such file or directory
root@ubuntu2204:~# sysctl -a | grep -i autogroup
5.18, noautogroup:
at@ubuntu2204:~$ uname -a
Linux ubuntu2204 5.18.0-051800-generic #202205222030 SMP
PREEMPT_DYNAMIC Sun May 22 20:33:46 UTC 2022 x86_64 x86_64 x86_64
GNU/Linux
at@ubuntu2204:~$ journalctl -b | grep -i autogroup
May 29 15:53:17 ubuntu2204 kernel: Command line:
BOOT_IMAGE=/boot/vmlinuz-5.18.0-051800-generic
root=UUID=20672a55-02fc-49b3-8c04-bd040f068096 ro
find_preseed=/preseed.cfg auto noprompt priority=critical locale=en_US
quiet splash noautogroup
May 29 15:53:17 ubuntu2204 kernel: Kernel command line:
BOOT_IMAGE=/boot/vmlinuz-5.18.0-051800-generic
root=UUID=20672a55-02fc-49b3-8c04-bd040f068096 ro
find_preseed=/preseed.cfg auto noprompt priority=critical locale=en_US
quiet splash noautogroup
May 29 15:53:17 ubuntu2204 kernel: failed when register_sysctl
sched_autogroup_sysctls to kernel
at@ubuntu2204:~$ cat /proc/sys/kernel/sched_autogroup_enabled
cat: /proc/sys/kernel/sched_autogroup_enabled: No such file or directory
root@ubuntu2204:~# cat /boot/config-5.1[78]* | grep -i config_sysctl=
CONFIG_SYSCTL=y
CONFIG_SYSCTL=y
root@ubuntu2204:~# cat /boot/config-5.1[78]* | grep -i autogroup
CONFIG_SCHED_AUTOGROUP=y
CONFIG_SCHED_AUTOGROUP=y
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: 5.18 missing /proc/sys/kernel/sched_autogroup_enabled?
2022-05-29 23:52 5.18 missing /proc/sys/kernel/sched_autogroup_enabled? Ivan Kozik
@ 2022-05-30 7:45 ` Peter Zijlstra
2022-05-30 9:48 ` Ivan Kozik
2022-05-30 10:45 ` [tip: sched/urgent] sched/autogroup: Fix sysctl move tip-bot2 for Peter Zijlstra
0 siblings, 2 replies; 4+ messages in thread
From: Peter Zijlstra @ 2022-05-30 7:45 UTC (permalink / raw)
To: Ivan Kozik; +Cc: linux-kernel, nizhen, mingo
On Sun, May 29, 2022 at 11:52:42PM +0000, Ivan Kozik wrote:
> Hello,
>
> I noticed that /proc/sys/kernel/sched_autogroup_enabled seems to have
> gone missing in 5.18. Am I doing something wrong, or is this a
> regression?
>
> I also noticed that booting 5.18 with "noautogroup" results in a
> "kernel: failed when register_sysctl sched_autogroup_sysctls to
> kernel" message. Because of the error and the missing
> /proc/sys/kernel/sched_autogroup_enabled, it is unclear whether
> autogroup is enabled or not.
*sigh*, I think this is yet another one of the sysctl move patches gone
bad :/ Specifically:
c8eaf6ac76f4 ("sched: move autogroup sysctls into its own file")
Does something like the below help?
---
diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c
index 16092b49ff6a..4ebaf97f7bd8 100644
--- a/kernel/sched/autogroup.c
+++ b/kernel/sched/autogroup.c
@@ -36,6 +36,7 @@ void __init autogroup_init(struct task_struct *init_task)
kref_init(&autogroup_default.kref);
init_rwsem(&autogroup_default.lock);
init_task->signal->autogroup = &autogroup_default;
+ sched_autogroup_sysctl_init();
}
void autogroup_free(struct task_group *tg)
@@ -219,7 +220,6 @@ void sched_autogroup_exit(struct signal_struct *sig)
static int __init setup_autogroup(char *str)
{
sysctl_sched_autogroup_enabled = 0;
- sched_autogroup_sysctl_init();
return 1;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: 5.18 missing /proc/sys/kernel/sched_autogroup_enabled?
2022-05-30 7:45 ` Peter Zijlstra
@ 2022-05-30 9:48 ` Ivan Kozik
2022-05-30 10:45 ` [tip: sched/urgent] sched/autogroup: Fix sysctl move tip-bot2 for Peter Zijlstra
1 sibling, 0 replies; 4+ messages in thread
From: Ivan Kozik @ 2022-05-30 9:48 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: linux-kernel, nizhen, mingo
On Mon, May 30, 2022 at 7:45 AM Peter Zijlstra <peterz@infradead.org> wrote:
> *sigh*, I think this is yet another one of the sysctl move patches gone
> bad :/ Specifically:
>
> c8eaf6ac76f4 ("sched: move autogroup sysctls into its own file")
>
> Does something like the below help?
Hi Peter,
Yes, your patch does fix both the missing
/proc/sys/kernel/sched_autogroup_enabled and the error when using
noautogroup.
Thank you,
Ivan
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip: sched/urgent] sched/autogroup: Fix sysctl move
2022-05-30 7:45 ` Peter Zijlstra
2022-05-30 9:48 ` Ivan Kozik
@ 2022-05-30 10:45 ` tip-bot2 for Peter Zijlstra
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot2 for Peter Zijlstra @ 2022-05-30 10:45 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Ivan Kozik, Peter Zijlstra (Intel), x86, linux-kernel
The following commit has been merged into the sched/urgent branch of tip:
Commit-ID: 82f586f923e3ac6062bc7867717a7f8afc09e0ff
Gitweb: https://git.kernel.org/tip/82f586f923e3ac6062bc7867717a7f8afc09e0ff
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Mon, 30 May 2022 09:45:38 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 30 May 2022 12:36:36 +02:00
sched/autogroup: Fix sysctl move
Ivan reported /proc/sys/kernel/sched_autogroup_enabled went walk-about
and using the noautogroup command line parameter would result in a
boot error message.
Turns out the sysctl move placed the init function wrong.
Fixes: c8eaf6ac76f4 ("sched: move autogroup sysctls into its own file")
Reported-by: Ivan Kozik <ivan@ludios.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Ivan Kozik <ivan@ludios.org>
Link: https://lkml.kernel.org/r/YpR2IqndgsyMzN00@worktop.programming.kicks-ass.net
---
kernel/sched/autogroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c
index 16092b4..4ebaf97 100644
--- a/kernel/sched/autogroup.c
+++ b/kernel/sched/autogroup.c
@@ -36,6 +36,7 @@ void __init autogroup_init(struct task_struct *init_task)
kref_init(&autogroup_default.kref);
init_rwsem(&autogroup_default.lock);
init_task->signal->autogroup = &autogroup_default;
+ sched_autogroup_sysctl_init();
}
void autogroup_free(struct task_group *tg)
@@ -219,7 +220,6 @@ void sched_autogroup_exit(struct signal_struct *sig)
static int __init setup_autogroup(char *str)
{
sysctl_sched_autogroup_enabled = 0;
- sched_autogroup_sysctl_init();
return 1;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-05-30 10:46 UTC | newest]
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2022-05-29 23:52 5.18 missing /proc/sys/kernel/sched_autogroup_enabled? Ivan Kozik
2022-05-30 7:45 ` Peter Zijlstra
2022-05-30 9:48 ` Ivan Kozik
2022-05-30 10:45 ` [tip: sched/urgent] sched/autogroup: Fix sysctl move tip-bot2 for Peter Zijlstra
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