The patch titled
cgroups: ability to stop res charge propagation on bounded ancestor
has been added to the -mm tree. Its filename is
cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor.patch
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Subject: cgroups: ability to stop res charge propagation on bounded ancestor
From: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Moving a task from a cgroup to another may require subtraction of its
resource charge from the old cgroup and adding it to the new one.
For this to happen, the uncharge/charge propagation can just stop when we
reach the common ancestor for the two cgroups. Further the performance
reasons, we also want to avoid to temporarily overload the common
ancestors with a non-accurate resource counter usage if we charge first
the new cgroup and uncharge the old one thereafter. This is going to be a
requirement for the coming max number of task subsystem.
To solve this, provide a pair of new API that can charge/uncharge a
resource counter until we reach a given ancestor.
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Acked-by: Paul Menage <paul@xxxxxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Aditya Kali <adityakali@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Kay Sievers <kay.sievers@xxxxxxxx>
Cc: Tim Hockin <thockin@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/res_counter.h | 19 ++++++++++++++++---
kernel/res_counter.c | 13 ++++++++-----
2 files changed, 24 insertions(+), 8 deletions(-)
diff -puN include/linux/res_counter.h~cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor include/linux/res_counter.h
--- a/include/linux/res_counter.h~cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor
+++ a/include/linux/res_counter.h
@@ -117,8 +117,16 @@ void res_counter_init(struct res_counter
int __must_check res_counter_charge_locked(struct res_counter *counter,
unsigned long val);
-int __must_check res_counter_charge(struct res_counter *counter,
- unsigned long val, struct res_counter **limit_fail_at);
+int __must_check res_counter_charge_until(struct res_counter *counter,
+ struct res_counter *limit,
+ unsigned long val,
+ struct res_counter **limit_fail_at);
+static inline int __must_check
+res_counter_charge(struct res_counter *counter, unsigned long val,
+ struct res_counter **limit_fail_at)
+{
+ return res_counter_charge_until(counter, NULL, val, limit_fail_at);
+}
/*
* uncharge - tell that some portion of the resource is released
@@ -131,7 +139,12 @@ int __must_check res_counter_charge(stru
*/
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 *limit,
+ unsigned long val);
+static inline void res_counter_uncharge(struct res_counter *counter, unsigned long val)
+{
+ res_counter_uncharge_until(counter, NULL, val);
+}
/**
* res_counter_margin - calculate chargeable space of a counter
diff -puN kernel/res_counter.c~cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor kernel/res_counter.c
--- a/kernel/res_counter.c~cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor
+++ a/kernel/res_counter.c
@@ -35,8 +35,9 @@ int res_counter_charge_locked(struct res
return 0;
}
-int res_counter_charge(struct res_counter *counter, unsigned long val,
- struct res_counter **limit_fail_at)
+int res_counter_charge_until(struct res_counter *counter,
+ struct res_counter *limit, unsigned long val,
+ struct res_counter **limit_fail_at)
{
int ret;
unsigned long flags;
@@ -44,7 +45,7 @@ int res_counter_charge(struct res_counte
*limit_fail_at = NULL;
local_irq_save(flags);
- for (c = counter; c != NULL; c = c->parent) {
+ for (c = counter; c != limit; c = c->parent) {
spin_lock(&c->lock);
ret = res_counter_charge_locked(c, val);
spin_unlock(&c->lock);
@@ -74,13 +75,15 @@ void res_counter_uncharge_locked(struct
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 *limit,
+ 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 != limit; c = c->parent) {
spin_lock(&c->lock);
res_counter_uncharge_locked(c, val);
spin_unlock(&c->lock);
_
Patches currently in -mm which might be from fweisbec@xxxxxxxxx are
linux-next.patch
tracex86-add-tracepoint-to-x86-timer-interrupt-handler.patch
tracex86-add-x86-irq-vector-entry-exit-tracepoints.patch
cgroups-more-safe-tasklist-locking-in-cgroup_attach_proc.patch
cgroups-fix-ordering-of-calls-in-cgroup_attach_proc.patch
cgroups-add-res_counter_write_u64-api.patch
cgroups-new-resource-counter-inheritance-api.patch
cgroups-add-previous-cgroup-in-can_attach_task-attach_task-callbacks.patch
cgroups-new-cancel_attach_task-subsystem-callback.patch
cgroups-new-cancel_attach_task-subsystem-callback-fix.patch
cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor.patch
cgroups-add-res-counter-common-ancestor-searching.patch
cgroups-add-res-counter-common-ancestor-searching-fix.patch
res_counter-allow-charge-failure-pointer-to-be-null.patch
cgroups-pull-up-res-counter-charge-failure-interpretation-to-caller.patch
cgroups-add-a-task-counter-subsystem.patch
cgroups-add-documentation-for-task-counter-subsystem.patch
cgroups-allow-subsystems-to-cancel-a-fork.patch
cgroups-convert-task-counter-to-use-the-subsys-fork-callback.patch
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