Messages in this thread | | | From | Paul Menage <> | Date | Mon, 25 Jul 2011 17:50:54 -0700 | Subject | Re: [PATCH 5/7] cgroups: Ability to stop res charge propagation on bounded ancestor |
| |
On Mon, Jul 11, 2011 at 7:15 AM, Frederic Weisbecker <fweisbec@gmail.com> wrote: > Moving a task from a cgroup to another may require to substract > its resource charge from the old cgroup and add 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@gmail.com>
Acked-by: Paul Menage <menage@google.com>
Looks good, thanks. Paul
> Cc: Paul Menage <menage@google.com> > Cc: Li Zefan <lizf@cn.fujitsu.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Aditya Kali <adityakali@google.com> > --- > include/linux/res_counter.h | 6 ++++++ > kernel/res_counter.c | 23 ++++++++++++++++++----- > 2 files changed, 24 insertions(+), 5 deletions(-) > > diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h > index 109d118..8c421ac 100644 > --- a/include/linux/res_counter.h > +++ b/include/linux/res_counter.h > @@ -117,6 +117,10 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent); > > int __must_check res_counter_charge_locked(struct res_counter *counter, > unsigned long val); > +int __must_check res_counter_charge_until(struct res_counter *counter, > + struct res_counter *limit, > + unsigned long val, > + struct res_counter **limit_fail_at); > int __must_check res_counter_charge(struct res_counter *counter, > unsigned long val, struct res_counter **limit_fail_at); > > @@ -131,6 +135,8 @@ int __must_check res_counter_charge(struct res_counter *counter, > */ > > void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val); > +void res_counter_uncharge_until(struct res_counter *counter, struct res_counter *limit, > + unsigned long val); > void res_counter_uncharge(struct res_counter *counter, unsigned long val); > > /** > diff --git a/kernel/res_counter.c b/kernel/res_counter.c > index 8cb0362..39f2513 100644 > --- a/kernel/res_counter.c > +++ b/kernel/res_counter.c > @@ -35,8 +35,9 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val) > 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_counter *counter, unsigned long val, > > *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); > @@ -66,6 +67,12 @@ done: > return ret; > } > > +int 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); > +} > + > void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val) > { > if (WARN_ON(counter->usage < val)) > @@ -74,13 +81,15 @@ 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 *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); > @@ -88,6 +97,10 @@ 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) > -- > 1.7.5.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |