On Fri, 09 Mar 2012 12:07:32 +0800 Sha Zhengju <handai.szj@xxxxxxxxx> wrote: > On 03/09/2012 11:40 AM, KAMEZAWA Hiroyuki wrote: > > On Tue, 6 Mar 2012 20:13:24 +0800 > > Sha Zhengju<handai.szj@xxxxxxxxx> 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. > >> > >> 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; > >> + } > >> + > > Could you clear thresholds->primary ? I don't like a pointer points to freed memory. > Do you meaning I should set ‘thresholds->primary = NULL‘ ? > But the following rcu_assign_pointer will do this : > > + /* If all events are unregistered, free the spare array */ > + if (!new) { > + kfree(thresholds->spare); > + thresholds->spare = NULL; > + } > + > rcu_assign_pointer(thresholds->primary, new);<---------*HERE* > Hm, ok. Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> BTW, can memory cgroup be destroyed while there are registered events ? -- 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>