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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: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Glauber Costa <glommer@parallels.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Frederic Weisbecker 2012-04-25 01:11:35 +02:00 committed by Tejun Heo
parent c4c27fbdda
commit 4d8438f044
3 changed files with 40 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/cgroups/resource_counter.txt
View File

@ -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)

2
include/linux/res_counter.h
View File

@ -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,

79
kernel/res_counter.c
View File

@ -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;
}
int res_counter_charge(struct res_counter *counter, unsigned long val,
struct res_counter **limit_fail_at)
{
int ret;
unsigned long flags;
struct res_counter *c, *u;
*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);
spin_unlock(&c->lock);
if (ret < 0) {
*limit_fail_at = c;
goto undo;
}
}
ret = 0;
goto done;
undo:
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,
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, r;
unsigned long flags;
struct res_counter *c;
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);
r = res_counter_charge_locked(c, val);
if (r)
c->usage += val;
r = res_counter_charge_locked(c, val, force);
spin_unlock(&c->lock);
if (r < 0 && ret == 0) {
*limit_fail_at = c;
if (r < 0 && !ret) {
ret = r;
*limit_fail_at = c;
if (!force)
break;
}
}
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);
}
}
local_irq_restore(flags);
return ret;
}
int res_counter_charge(struct res_counter *counter, unsigned long val,
struct res_counter **limit_fail_at)
{
return __res_counter_charge(counter, val, limit_fail_at, false);
}
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))