On Thu, Mar 08, 2012 at 10:11:32AM +0800, Sha Zhengju wrote: > On 03/08/2012 07:08 AM, Kirill A. Shutemov wrote: > >On Tue, Mar 06, 2012 at 08:13:24PM +0800, Sha Zhengju wrote: > >>From: Sha Zhengju<handai.szj@xxxxxxxxxx> > >> > >>When the last event is unregistered, there is no need to keep the spare > >>array anymore. So free it to avoid memory leak. > >It's not a leak. It will be freed on next event register. > > > Yeah, I noticed that. But what if it is just the last one and no more > event registering ? See my question below. ;) > >Yeah, we don't have to keep spare if primary is empty. But is it worth to > >make code more complicated to save few bytes of memory? > > > >>Signed-off-by: Sha Zhengju<handai.szj@xxxxxxxxxx> > >> > >>--- > >> mm/memcontrol.c | 6 ++++++ > >> 1 files changed, 6 insertions(+), 0 deletions(-) > >> > >>diff --git a/mm/memcontrol.c b/mm/memcontrol.c > >>index 22d94f5..3c09a84 100644 > >>--- a/mm/memcontrol.c > >>+++ b/mm/memcontrol.c > >>@@ -4412,6 +4412,12 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, > >> swap_buffers: > >> /* Swap primary and spare array */ > >> thresholds->spare = thresholds->primary; > >>+ /* If all events are unregistered, free the spare array */ > >>+ if (!new) { > >>+ kfree(thresholds->spare); > >>+ thresholds->spare = NULL; > >>+ } > >>+ > >> rcu_assign_pointer(thresholds->primary, new); > >> > >> /* To be sure that nobody uses thresholds */ > >>-- > >>1.7.4.1 > >> > -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>