The patch titled
Subject: rescounters: add res_counter_uncharge_until()
has been added to the -mm tree. Its filename is
rescounters-add-res_counter_uncharge_until.patch
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From: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Subject: rescounters: add res_counter_uncharge_until()
When killing a 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 wastes 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 the operation is atomic and efficient.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ying Han <yinghan@xxxxxxxxxx>
Cc: Glauber Costa <glommer@xxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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 -puN Documentation/cgroups/resource_counter.txt~rescounters-add-res_counter_uncharge_until Documentation/cgroups/resource_counter.txt
--- a/Documentation/cgroups/resource_counter.txt~rescounters-add-res_counter_uncharge_until
+++ a/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 -puN include/linux/res_counter.h~rescounters-add-res_counter_uncharge_until include/linux/res_counter.h
--- a/include/linux/res_counter.h~rescounters-add-res_counter_uncharge_until
+++ a/include/linux/res_counter.h
@@ -135,6 +135,9 @@ int __must_check res_counter_charge_nofa
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 -puN kernel/res_counter.c~rescounters-add-res_counter_uncharge_until kernel/res_counter.c
--- a/kernel/res_counter.c~rescounters-add-res_counter_uncharge_until
+++ a/kernel/res_counter.c
@@ -94,13 +94,15 @@ 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 *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);
@@ -108,6 +110,10 @@ void res_counter_uncharge(struct res_cou
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)
_
Subject: Subject: rescounters: add res_counter_uncharge_until()
Patches currently in -mm which might be from fweisbec@xxxxxxxxx are
linux-next.patch
memcg-fix-error-code-in-hugetlb_force_memcg_empty.patch
rescounters-add-res_counter_uncharge_until.patch
memcg-use-res_counter_uncharge_until-in-move_parent.patch
memcg-move-charges-to-root-cgroup-if-use_hierarchy=0.patch
memcg-dont-uncharge-in-mem_cgroup_move_account.patch
remove-__must_check-for-res_counter_charge_nofail.patch
locking-add-kern_cont-when-needed-to-self-test.patch
stack-usage-add-pid-to-warning-printk-in-check_stack_usage.patch
tools-selftests-add-mq_perf_tests.patch
tools-selftests-add-mq_perf_tests-checkpatch-fixes.patch
syscalls-x86-add-__nr_kcmp-syscall-v8.patch
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