| Message ID | 1337938328-11537-2-git-send-email-glommer@parallels.com |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri 25-05-12 13:32:07, 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 <glommer@parallels.com> > Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Just one comment below > CC: Tejun Heo <tj@kernel.org> > CC: Li Zefan <lizefan@huawei.com> > CC: Johannes Weiner <hannes@cmpxchg.org> > CC: Michal Hocko <mhocko@suse.cz> > CC: Andrew Morton <akpm@linux-foundation.org> > --- > mm/memcontrol.c | 24 +++++++++++++----------- > 1 files changed, 13 insertions(+), 11 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 932a734..0b4b4c8 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c [...] > @@ -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) What about if (is_vmalloc_addr(memcg)) > + kfree(memcg); > + else > + vfree(memcg); > }
On 05/25/2012 01:50 PM, Michal Hocko wrote: > On Fri 25-05-12 13:32:07, 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<glommer@parallels.com> >> Acked-by: Kamezawa Hiroyuki<kamezawa.hiroyu@jp.fujitsu.com> > > Acked-by: Michal Hocko<mhocko@suse.cz> > > Just one comment below > >> CC: Tejun Heo<tj@kernel.org> >> CC: Li Zefan<lizefan@huawei.com> >> CC: Johannes Weiner<hannes@cmpxchg.org> >> CC: Michal Hocko<mhocko@suse.cz> >> CC: Andrew Morton<akpm@linux-foundation.org> >> --- >> mm/memcontrol.c | 24 +++++++++++++----------- >> 1 files changed, 13 insertions(+), 11 deletions(-) >> >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 932a734..0b4b4c8 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c > [...] >> @@ -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) > > What about > if (is_vmalloc_addr(memcg)) >> + kfree(memcg); >> + else >> + vfree(memcg); >> } > Could be, but I believe this one is already in Andrew's tree from last submission (might be wrong) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 932a734..0b4b4c8 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)