Messages in this thread | | | Date | Tue, 16 Oct 2012 17:20:34 +0900 | From | Kamezawa Hiroyuki <> | Subject | Re: [PATCH v4 08/14] res_counter: return amount of charges after res_counter_uncharge |
| |
(2012/10/08 19:06), Glauber Costa wrote: > It is useful to know how many charges are still left after a call to > res_counter_uncharge. While it is possible to issue a res_counter_read > after uncharge, this can be racy. > > If we need, for instance, to take some action when the counters drop > down to 0, only one of the callers should see it. This is the same > semantics as the atomic variables in the kernel. > > Since the current return value is void, we don't need to worry about > anything breaking due to this change: nobody relied on that, and only > users appearing from now on will be checking this value. > > Signed-off-by: Glauber Costa <glommer@parallels.com> > CC: Michal Hocko <mhocko@suse.cz> > CC: Johannes Weiner <hannes@cmpxchg.org> > CC: Suleiman Souhlal <suleiman@google.com> > CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > --- > Documentation/cgroups/resource_counter.txt | 7 ++++--- > include/linux/res_counter.h | 12 +++++++----- > kernel/res_counter.c | 20 +++++++++++++------- > 3 files changed, 24 insertions(+), 15 deletions(-)
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
| |