(2012/05/14 19:08), Frederic Weisbecker wrote:
> 2012/5/14 KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>:
>> (2012/05/12 6:19), Andrew Morton wrote:
>>
>>> On Fri, 11 May 2012 18:47:06 +0900
>>> KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>>>
>>>> From: Frederic Weisbecker <fweisbec@xxxxxxxxx>
>>>>
>>>> At killing res_counter which is a child of other counter,
>>>> we need to do
>>>> res_counter_uncharge(child, xxx)
>>>> res_counter_charge(parent, xxx)
>>>>
>>>> This is not atomic and wasting cpu. This patch adds
>>>> res_counter_uncharge_until(). This function's uncharge propagates
>>>> to ancestors until specified res_counter.
>>>>
>>>> res_counter_uncharge_until(child, parent, xxx)
>>>>
>>>> Now, ops is atomic and efficient.
>>>>
>>>> Changelog since v2
>>>> - removed unnecessary lines.
>>>> - Fixed 'From' , this patch comes from his series. Please signed-off-by if good.
>>>>
>>>> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>>>
>>> Frederic's Signed-off-by: is unavaliable?
>>>
>>
>> I didn't add his Signed-off because I modified his orignal patch a little...
>> I dropped res_counter_charge_until() because it's not used in this series,
>> I have no justification for adding it.
>> The idea of res_counter_uncharge_until() is from his patch.
>
> The property of Signed-off-by is that as long as you
> carry/relay/modify a patch, you add your
> own signed-off-by. But you can't remove the signed off by of somebody
> in the chain.
>
> Even if you did a change in the patch, you need to preserve the chain.
>
Oh, sorry.
> There may be some special cases with "Original-patch-from:" tags used when
> one heavily inspire from a patch without taking much of its original code.
>
Is this ok ?
==
[PATCH 2/6] memcg: add res_counter_uncharge_until()
From: Frederic Weisbecker <fweisbec@xxxxxxxxx>
At killing res_counter which is a child of other counter,
we need to do
res_counter_uncharge(child, xxx)
res_counter_charge(parent, xxx)
This is not atomic and wasting cpu. This patch adds
res_counter_uncharge_until(). This function's uncharge propagates
to ancestors until specified res_counter.
res_counter_uncharge_until(child, parent, xxx)
Now, ops is atomic and efficient.
Changelog since v2
- removed unnecessary lines.
- added 'From' , this patch comes from his one.
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
Documentation/cgroups/resource_counter.txt | 8 ++++++++
include/linux/res_counter.h | 3 +++
kernel/res_counter.c | 10 ++++++++--
3 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt
index 95b24d7..703103a 100644
--- a/Documentation/cgroups/resource_counter.txt
+++ b/Documentation/cgroups/resource_counter.txt
@@ -92,6 +92,14 @@ to work with it.
The _locked routines imply that the res_counter->lock is taken.
+ f. void res_counter_uncharge_until
+ (struct res_counter *rc, struct res_counter *top,
+ unsinged long val)
+
+ Almost same as res_cunter_uncharge() but propagation of uncharge
+ stops when rc == top. This is useful when kill a res_coutner in
+ child cgroup.
+
2.1 Other accounting routines
There are more routines that may help you with common needs, like
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index da81af0..d11c1cd 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -135,6 +135,9 @@ int __must_check res_counter_charge_nofail(struct res_counter *counter,
void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
void res_counter_uncharge(struct res_counter *counter, unsigned long val);
+void res_counter_uncharge_until(struct res_counter *counter,
+ struct res_counter *top,
+ unsigned long val);
/**
* res_counter_margin - calculate chargeable space of a counter
* @cnt: the counter
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index d508363..d9ea45e 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -99,13 +99,15 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
counter->usage -= val;
}
-void res_counter_uncharge(struct res_counter *counter, unsigned long val)
+void res_counter_uncharge_until(struct res_counter *counter,
+ struct res_counter *top,
+ unsigned long val)
{
unsigned long flags;
struct res_counter *c;
local_irq_save(flags);
- for (c = counter; c != NULL; c = c->parent) {
+ for (c = counter; c != top; c = c->parent) {
spin_lock(&c->lock);
res_counter_uncharge_locked(c, val);
spin_unlock(&c->lock);
@@ -113,6 +115,10 @@ void res_counter_uncharge(struct res_counter *counter, unsigned long val)
local_irq_restore(flags);
}
+void res_counter_uncharge(struct res_counter *counter, unsigned long val)
+{
+ res_counter_uncharge_until(counter, NULL, val);
+}
static inline unsigned long long *
res_counter_member(struct res_counter *counter, int member)
--
1.7.4.1
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