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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2012-05-30 02:07:03 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-30 03:22:27 +0400 |
| commit | 2bb2ba9d51a8044a71a29608d2c4ef8f5b2d57a2 (patch) | |
| tree | 5e58869c606c541d41a9bfa62aa6e8bc42cae5ac | |
| parent | f9be23d6da035241b7687b25e64401171986dcef (diff) | |
| download | linux-2bb2ba9d51a8044a71a29608d2c4ef8f5b2d57a2.tar.xz | |
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: Frederic Weisbecker <fweisbec@redhat.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | Documentation/cgroups/resource_counter.txt | 8 | ||||
| -rw-r--r-- | include/linux/res_counter.h | 3 | ||||
| -rw-r--r-- | 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 f3c4ec3626a2..0c4a344e78fa 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 fb201896a8b0..5de7a146ead9 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 bebe2b170d49..ad581aa2369a 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -94,13 +94,15 @@ 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); @@ -108,6 +110,10 @@ 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) |