* [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children
@ 2012-07-05 10:55 Wanpeng Li
2012-07-09 4:43 ` Kamezawa Hiroyuki
2012-07-09 12:01 ` Michal Hocko
0 siblings, 2 replies; 4+ messages in thread
From: Wanpeng Li @ 2012-07-05 10:55 UTC (permalink / raw)
To: Andrew Morton
Cc: Johannes Weiner, Michal Hocko, KAMEZAWA Hiroyuki, linux-mm,
linux-kernel, Wanpeng Li
From: Wanpeng Li <liwp@linux.vnet.ibm.com>
When oom-kill-disable modified by the user and current memcg use_hierarchy,
the change can occur, provided the current memcg has no children. If it
has children, return -EBUSY is enough.
Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
---
mm/memcontrol.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 63e36e7..4b64fe0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4521,11 +4521,14 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
cgroup_lock();
/* oom-kill-disable is a flag for subhierarchy. */
- if ((parent->use_hierarchy) ||
- (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+ if (parent->use_hierarchy) {
cgroup_unlock();
return -EINVAL;
+ } else if (memcg->use_hierarchy && !list_empty(&cgrp->children)) {
+ cgroup_unlock();
+ return -EBUSY;
}
+
memcg->oom_kill_disable = val;
if (!val)
memcg_oom_recover(memcg);
--
1.7.5.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children
2012-07-05 10:55 [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children Wanpeng Li
@ 2012-07-09 4:43 ` Kamezawa Hiroyuki
2012-07-09 5:10 ` Wanpeng Li
2012-07-09 12:01 ` Michal Hocko
1 sibling, 1 reply; 4+ messages in thread
From: Kamezawa Hiroyuki @ 2012-07-09 4:43 UTC (permalink / raw)
To: Wanpeng Li
Cc: Andrew Morton, Johannes Weiner, Michal Hocko, linux-mm,
linux-kernel
(2012/07/05 19:55), Wanpeng Li wrote:
> From: Wanpeng Li <liwp@linux.vnet.ibm.com>
>
> When oom-kill-disable modified by the user and current memcg use_hierarchy,
> the change can occur, provided the current memcg has no children. If it
> has children, return -EBUSY is enough.
>
> Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
I'm sorry what is the point ? You think -EBUSY should be returned in this case
rather than -EINVAl ? Then, why ?
> ---
> mm/memcontrol.c | 7 +++++--
> 1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 63e36e7..4b64fe0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4521,11 +4521,14 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
>
> cgroup_lock();
> /* oom-kill-disable is a flag for subhierarchy. */
> - if ((parent->use_hierarchy) ||
> - (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
> + if (parent->use_hierarchy) {
> cgroup_unlock();
> return -EINVAL;
> + } else if (memcg->use_hierarchy && !list_empty(&cgrp->children)) {
> + cgroup_unlock();
> + return -EBUSY;
> }
> +
> memcg->oom_kill_disable = val;
> if (!val)
> memcg_oom_recover(memcg);
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children
2012-07-09 4:43 ` Kamezawa Hiroyuki
@ 2012-07-09 5:10 ` Wanpeng Li
0 siblings, 0 replies; 4+ messages in thread
From: Wanpeng Li @ 2012-07-09 5:10 UTC (permalink / raw)
To: Kamezawa Hiroyuki
Cc: Johannes Weiner, Michal Hocko, Andrew Morton, linux-mm,
linux-kernel, Wanpeng Li
On Mon, Jul 09, 2012 at 01:43:23PM +0900, Kamezawa Hiroyuki wrote:
>(2012/07/05 19:55), Wanpeng Li wrote:
>> From: Wanpeng Li <liwp@linux.vnet.ibm.com>
>>
>> When oom-kill-disable modified by the user and current memcg use_hierarchy,
>> the change can occur, provided the current memcg has no children. If it
>> has children, return -EBUSY is enough.
>>
>> Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
>
>I'm sorry what is the point ? You think -EBUSY should be returned in this case
>rather than -EINVAl ? Then, why ?
just like in function cmem_cgroup_hierarchy_write:
if((!parent_memcg || !parent_memcg->use_hierarchy) &&
(val == 1 || val == 0) {
if (list_empty(&cont->children))
memcg->use_hierarchy = val;
else
return -EBUSY;
} else
return = -EINVAL;
If memcg->use_hierarchy && has children memcg, the user can try again
if children memcg disappear. Or I miss something ....
Regards,
Wanpeng Li
>
>
>> ---
>> mm/memcontrol.c | 7 +++++--
>> 1 files changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index 63e36e7..4b64fe0 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -4521,11 +4521,14 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
>>
>> cgroup_lock();
>> /* oom-kill-disable is a flag for subhierarchy. */
>> - if ((parent->use_hierarchy) ||
>> - (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
>> + if (parent->use_hierarchy) {
>> cgroup_unlock();
>> return -EINVAL;
>> + } else if (memcg->use_hierarchy && !list_empty(&cgrp->children)) {
>> + cgroup_unlock();
>> + return -EBUSY;
>> }
>> +
>> memcg->oom_kill_disable = val;
>> if (!val)
>> memcg_oom_recover(memcg);
>>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children
2012-07-05 10:55 [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children Wanpeng Li
2012-07-09 4:43 ` Kamezawa Hiroyuki
@ 2012-07-09 12:01 ` Michal Hocko
1 sibling, 0 replies; 4+ messages in thread
From: Michal Hocko @ 2012-07-09 12:01 UTC (permalink / raw)
To: Wanpeng Li
Cc: Andrew Morton, Johannes Weiner, KAMEZAWA Hiroyuki, linux-mm,
linux-kernel
On Thu 05-07-12 18:55:08, Wanpeng Li wrote:
> From: Wanpeng Li <liwp@linux.vnet.ibm.com>
>
> When oom-kill-disable modified by the user and current memcg use_hierarchy,
> the change can occur, provided the current memcg has no children. If it
> has children, return -EBUSY is enough.
I do not think EBUSY makes any difference. I would much rather see the
test go away...
> Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
> ---
> mm/memcontrol.c | 7 +++++--
> 1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 63e36e7..4b64fe0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4521,11 +4521,14 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
>
> cgroup_lock();
> /* oom-kill-disable is a flag for subhierarchy. */
> - if ((parent->use_hierarchy) ||
> - (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
> + if (parent->use_hierarchy) {
> cgroup_unlock();
> return -EINVAL;
> + } else if (memcg->use_hierarchy && !list_empty(&cgrp->children)) {
> + cgroup_unlock();
> + return -EBUSY;
> }
> +
> memcg->oom_kill_disable = val;
> if (!val)
> memcg_oom_recover(memcg);
> --
> 1.7.5.4
>
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
^ permalink raw reply [flat|nested] 4+ messages in thread
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2012-07-05 10:55 [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children Wanpeng Li
2012-07-09 4:43 ` Kamezawa Hiroyuki
2012-07-09 5:10 ` Wanpeng Li
2012-07-09 12:01 ` Michal Hocko
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