lkml.org 
[lkml]   [2014]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/1] memcg: kill start_kernel()->mm_init_owner(init_mm)
On Fri 18-04-14 21:13:22, Oleg Nesterov wrote:
> Remove start_kernel()->mm_init_owner(&init_mm, &init_task).
>
> This doesn't really hurt but unnecessary and misleading. init_task
> is the "swapper" thread == current, its ->mm is always NULL. And
> init_mm can only be used as ->active_mm, not as ->mm.

OK, this should work because mem_cgroup_from_task can handle NULL
task so even if somebody provided init_mm it will work properly.

But to be honest, I have no idea why mm_init_owner was called here.

> mm_init_owner() has a single caller with this patch, perhaps it
> should die. mm_init() can initialize ->owner under #ifdef.
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Reviewed-by: Michal Hocko <mhocko@suse.cz>

> ---
> init/main.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/init/main.c b/init/main.c
> index 3815895..17090bb 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -507,7 +507,6 @@ asmlinkage void __init start_kernel(void)
> page_address_init();
> pr_notice("%s", linux_banner);
> setup_arch(&command_line);
> - mm_init_owner(&init_mm, &init_task);
> mm_init_cpumask(&init_mm);
> setup_command_line(command_line);
> setup_nr_cpu_ids();
> --
> 1.5.5.1
>
>

--
Michal Hocko
SUSE Labs


\
 
 \ /
  Last update: 2014-04-22 16:01    [W:0.119 / U:3.352 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site