[PATCH -next] cpuset: initialize cpuset a bit early

[PATCH -next] cpuset: initialize cpuset a bit early

[Zefan Li]

Now we call ss->bind() in cgroup_init(), so cgroup_init() will
call cpuset_bind() and then the latter will access top_cpuset's
cpumask, which is NULL, because cpuset_init() is called after
cgroup_init()

The simplest fix is to swap cgroup_init() and cpuset_init().

Cc: Vladimir Davydov <vdavydov@parallels.com>
Fixes: 295458e67284 ("cgroup: call cgroup_subsys->bind on cgroup subsys initialization")
Reported by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
 init/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/main.c b/init/main.c
index 61b9937..50d1e95 100644
--- a/init/main.c
+++ b/init/main.c
@@ -667,8 +667,8 @@ asmlinkage __visible void __init start_kernel(void)
 	page_writeback_init();
 	proc_root_init();
 	nsfs_init();
-	cgroup_init();
 	cpuset_init();
+	cgroup_init();
 	taskstats_init_early();
 	delayacct_init();
 
-- 
1.8.0.2

Re: [PATCH -next] cpuset: initialize cpuset a bit early

[Ming Lei]

On Wed, Mar 4, 2015 at 5:09 PM, Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> wrote:
> Now we call ss->bind() in cgroup_init(), so cgroup_init() will
> call cpuset_bind() and then the latter will access top_cpuset's
> cpumask, which is NULL, because cpuset_init() is called after
> cgroup_init()
>
> The simplest fix is to swap cgroup_init() and cpuset_init().
>
> Cc: Vladimir Davydov <vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> Fixes: 295458e67284 ("cgroup: call cgroup_subsys->bind on cgroup subsys initialization")
> Reported by: Ming Lei <tom.leiming-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Looks this patch does fix the boot issue.

> ---
>  init/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/init/main.c b/init/main.c
> index 61b9937..50d1e95 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -667,8 +667,8 @@ asmlinkage __visible void __init start_kernel(void)
>         page_writeback_init();
>         proc_root_init();
>         nsfs_init();
> -       cgroup_init();
>         cpuset_init();
> +       cgroup_init();
>         taskstats_init_early();
>         delayacct_init();
>
> --
> 1.8.0.2
>


Thanks
Ming Lei

Re: [PATCH -next] cpuset: initialize cpuset a bit early

[Vladimir Davydov]

On Wed, Mar 04, 2015 at 05:09:33PM +0800, Zefan Li wrote:
> Now we call ss->bind() in cgroup_init(), so cgroup_init() will
> call cpuset_bind() and then the latter will access top_cpuset's
> cpumask, which is NULL, because cpuset_init() is called after
> cgroup_init()
> 
> The simplest fix is to swap cgroup_init() and cpuset_init().
> 
> Cc: Vladimir Davydov <vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> Fixes: 295458e67284 ("cgroup: call cgroup_subsys->bind on cgroup subsys initialization")
> Reported by: Ming Lei <tom.leiming-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Acked-by: Vladimir Davydov <vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>

Thanks!

Re: [PATCH -next] cpuset: initialize cpuset a bit early

[Tejun Heo]

On Wed, Mar 04, 2015 at 05:09:33PM +0800, Zefan Li wrote:
> Now we call ss->bind() in cgroup_init(), so cgroup_init() will
> call cpuset_bind() and then the latter will access top_cpuset's
> cpumask, which is NULL, because cpuset_init() is called after
> cgroup_init()
> 
> The simplest fix is to swap cgroup_init() and cpuset_init().
> 
> Cc: Vladimir Davydov <vdavydov-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> Fixes: 295458e67284 ("cgroup: call cgroup_subsys->bind on cgroup subsys initialization")
> Reported by: Ming Lei <tom.leiming-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Applied to cgroup/for-4.1.

Thanks.

-- 
tejun