Commit 4d8438f0 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Tejun Heo
Browse files

res_counter: Merge res_counter_charge and res_counter_charge_nofail 



These two functions do almost the same thing and duplicate some code.
Merge their implementation into a single common function.
res_counter_charge_locked() takes one more parameter but it doesn't seem
to be used outside res_counter.c yet anyway.

There is no (intended) change in the behaviour.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarGlauber Costa <glommer@parallels.com>
Acked-by: default avatarKirill A. Shutemov <kirill@shutemov.name>
Cc: Li Zefan <lizefan@huawei.com>
parent c4c27fbd

Documentation/cgroups/resource_counter.txt

+2 −2
Original line number Diff line number Diff line
@@ -77,11 +77,11 @@ to work with it. 
	where the charging failed.



 d. int res_counter_charge_locked

			(struct res_counter *rc, unsigned long val)

			(struct res_counter *rc, unsigned long val, bool force)



	The same as res_counter_charge(), but it must not acquire/release the

	res_counter->lock internally (it must be called with res_counter->lock

	held).

	held). The force parameter indicates whether we can bypass the limit.



 e. void res_counter_uncharge[_locked]

			(struct res_counter *rc, unsigned long val)

include/linux/res_counter.h

+1 −1
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ 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);

					   unsigned long val, bool force);

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_nofail(struct res_counter *counter,

kernel/res_counter.c

+34 −39
Original line number Diff line number Diff line
@@ -22,75 +22,70 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent) 
	counter->parent = parent;

}



int res_counter_charge_locked(struct res_counter *counter, unsigned long val)

int res_counter_charge_locked(struct res_counter *counter, unsigned long val,

			      bool force)

{

	int ret = 0;



	if (counter->usage + val > counter->limit) {

		counter->failcnt++;

		return -ENOMEM;

		ret = -ENOMEM;

		if (!force)

			return ret;

	}



	counter->usage += val;

	if (counter->usage > counter->max_usage)

	if (!force && counter->usage > counter->max_usage)

		counter->max_usage = counter->usage;

	return 0;

	return ret;

}



int res_counter_charge(struct res_counter *counter, unsigned long val,

			struct res_counter **limit_fail_at)

static int __res_counter_charge(struct res_counter *counter, unsigned long val,

				struct res_counter **limit_fail_at, bool force)

{

	int ret;

	int ret, r;

	unsigned long flags;

	struct res_counter *c, *u;



	r = ret = 0;

	*limit_fail_at = NULL;

	local_irq_save(flags);

	for (c = counter; c != NULL; c = c->parent) {

		spin_lock(&c->lock);

		ret = res_counter_charge_locked(c, val);

		r = res_counter_charge_locked(c, val, force);

		spin_unlock(&c->lock);

		if (ret < 0) {

		if (r < 0 && !ret) {

			ret = r;

			*limit_fail_at = c;

			goto undo;

			if (!force)

				break;

		}

	}

	ret = 0;

	goto done;

undo:



	if (ret < 0 && !force) {

		for (u = counter; u != c; u = u->parent) {

			spin_lock(&u->lock);

			res_counter_uncharge_locked(u, val);

			spin_unlock(&u->lock);

		}

done:

	}

	local_irq_restore(flags);



	return ret;

}



int res_counter_charge_nofail(struct res_counter *counter, unsigned long val,

int res_counter_charge(struct res_counter *counter, unsigned long val,

			struct res_counter **limit_fail_at)

{

	int ret, r;

	unsigned long flags;

	struct res_counter *c;



	r = ret = 0;

	*limit_fail_at = NULL;

	local_irq_save(flags);

	for (c = counter; c != NULL; c = c->parent) {

		spin_lock(&c->lock);

		r = res_counter_charge_locked(c, val);

		if (r)

			c->usage += val;

		spin_unlock(&c->lock);

		if (r < 0 && ret == 0) {

			*limit_fail_at = c;

			ret = r;

		}

	return __res_counter_charge(counter, val, limit_fail_at, false);

}

	local_irq_restore(flags);



	return ret;

int res_counter_charge_nofail(struct res_counter *counter, unsigned long val,

			      struct res_counter **limit_fail_at)

{

	return __res_counter_charge(counter, val, limit_fail_at, true);

}



void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)

{

	if (WARN_ON(counter->usage < val))

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