res_counter: update documentation

After the introduction of resource counters hierarchies
(28dbc4b6a0) the prototypes of
res_counter_init() and res_counter_charge() have been changed.

Keep the documentation consistent with the actual function prototypes.

Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Righi 2009-04-13 14:39:58 -07:00 committed by Linus Torvalds
parent bdff549ebe
commit 5341cfab94

View file

@ -47,13 +47,18 @@ to work with it.
2. Basic accounting routines 2. Basic accounting routines
a. void res_counter_init(struct res_counter *rc) a. void res_counter_init(struct res_counter *rc,
struct res_counter *rc_parent)
Initializes the resource counter. As usual, should be the first Initializes the resource counter. As usual, should be the first
routine called for a new counter. routine called for a new counter.
b. int res_counter_charge[_locked] The struct res_counter *parent can be used to define a hierarchical
(struct res_counter *rc, unsigned long val) child -> parent relationship directly in the res_counter structure,
NULL can be used to define no relationship.
c. int res_counter_charge(struct res_counter *rc, unsigned long val,
struct res_counter **limit_fail_at)
When a resource is about to be allocated it has to be accounted When a resource is about to be allocated it has to be accounted
with the appropriate resource counter (controller should determine with the appropriate resource counter (controller should determine
@ -67,15 +72,25 @@ to work with it.
* if the charging is performed first, then it should be uncharged * if the charging is performed first, then it should be uncharged
on error path (if the one is called). on error path (if the one is called).
c. void res_counter_uncharge[_locked] If the charging fails and a hierarchical dependency exists, the
limit_fail_at parameter is set to the particular res_counter element
where the charging failed.
d. int res_counter_charge_locked
(struct res_counter *rc, unsigned long val)
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).
e. void res_counter_uncharge[_locked]
(struct res_counter *rc, unsigned long val) (struct res_counter *rc, unsigned long val)
When a resource is released (freed) it should be de-accounted When a resource is released (freed) it should be de-accounted
from the resource counter it was accounted to. This is called from the resource counter it was accounted to. This is called
"uncharging". "uncharging".
The _locked routines imply that the res_counter->lock is taken. The _locked routines imply that the res_counter->lock is taken.
2.1 Other accounting routines 2.1 Other accounting routines