(2012/06/18 19:27), Glauber Costa wrote: > Right now we free struct memcg with kfree right after a > rcu grace period, but defer it if we need to use vfree() to get > rid of that memory area. We do that by need, because we need vfree > to be called in a process context. > > This patch unifies this behavior, by ensuring that even kfree will > happen in a separate thread. The goal is to have a stable place to > call the upcoming jump label destruction function outside the realm > of the complicated and quite far-reaching cgroup lock (that can't be > held when calling neither the cpu_hotplug.lock nor the jump_label_mutex) > > Signed-off-by: Glauber Costa<[email protected]> > CC: Tejun Heo<[email protected]> > CC: Li Zefan<[email protected]> > CC: Kamezawa Hiroyuki<[email protected]> > CC: Johannes Weiner<[email protected]> > CC: Michal Hocko<[email protected]>
How about cut out this patch and merge first as simple cleanu up and to reduce patch stack on your side ? Acked-by: KAMEZAWA Hiroyuki <[email protected]> > --- > mm/memcontrol.c | 24 +++++++++++++----------- > 1 file changed, 13 insertions(+), 11 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index e3b528e..ce15be4 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -245,8 +245,8 @@ struct mem_cgroup { > */ > struct rcu_head rcu_freeing; > /* > - * But when using vfree(), that cannot be done at > - * interrupt time, so we must then queue the work. > + * We also need some space for a worker in deferred freeing. > + * By the time we call it, rcu_freeing is not longer in use. > */ > struct work_struct work_freeing; > }; > @@ -4826,23 +4826,28 @@ out_free: > } > > /* > - * Helpers for freeing a vzalloc()ed mem_cgroup by RCU, > + * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, > * but in process context. The work_freeing structure is overlaid > * on the rcu_freeing structure, which itself is overlaid on memsw. > */ > -static void vfree_work(struct work_struct *work) > +static void free_work(struct work_struct *work) > { > struct mem_cgroup *memcg; > + int size = sizeof(struct mem_cgroup); > > memcg = container_of(work, struct mem_cgroup, work_freeing); > - vfree(memcg); > + if (size< PAGE_SIZE) > + kfree(memcg); > + else > + vfree(memcg); > } > -static void vfree_rcu(struct rcu_head *rcu_head) > + > +static void free_rcu(struct rcu_head *rcu_head) > { > struct mem_cgroup *memcg; > > memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); > - INIT_WORK(&memcg->work_freeing, vfree_work); > + INIT_WORK(&memcg->work_freeing, free_work); > schedule_work(&memcg->work_freeing); > } > > @@ -4868,10 +4873,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) > free_mem_cgroup_per_zone_info(memcg, node); > > free_percpu(memcg->stat); > - if (sizeof(struct mem_cgroup)< PAGE_SIZE) > - kfree_rcu(memcg, rcu_freeing); > - else > - call_rcu(&memcg->rcu_freeing, vfree_rcu); > + call_rcu(&memcg->rcu_freeing, free_rcu); > } > > static void mem_cgroup_get(struct mem_cgroup *memcg) _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
