Messages in this thread | | | Date | Mon, 26 Sep 2011 19:49:43 -0300 | From | Glauber Costa <> | Subject | Re: [PATCH v3 6/7] tcp buffer limitation: per-cgroup limit |
| |
On 09/26/2011 08:02 AM, KAMEZAWA Hiroyuki wrote: > On Sat, 24 Sep 2011 10:30:42 -0300 > Glauber Costa<glommer@parallels.com> wrote: > >> On 09/22/2011 03:01 AM, Greg Thelen wrote: >>> On Sun, Sep 18, 2011 at 5:56 PM, Glauber Costa<glommer@parallels.com> wrote: >>>> +static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) >>>> +{ >>>> + return (mem == root_mem_cgroup); >>>> +} >>>> + >>> >>> Why are you adding a copy of mem_cgroup_is_root(). I see one already >>> in v3.0. Was it deleted in a previous patch? >> >> Already answered by another good samaritan. >> >>>> +static int tcp_write_maxmem(struct cgroup *cgrp, struct cftype *cft, u64 val) >>>> +{ >>>> + struct mem_cgroup *sg = mem_cgroup_from_cont(cgrp); >>>> + struct mem_cgroup *parent = parent_mem_cgroup(sg); >>>> + struct net *net = current->nsproxy->net_ns; >>>> + int i; >>>> + >>>> + if (!cgroup_lock_live_group(cgrp)) >>>> + return -ENODEV; >>> >>> Why is cgroup_lock_live_cgroup() needed here? Does it protect updates >>> to sg->tcp_prot_mem[*]? >>> >>>> +static u64 tcp_read_maxmem(struct cgroup *cgrp, struct cftype *cft) >>>> +{ >>>> + struct mem_cgroup *sg = mem_cgroup_from_cont(cgrp); >>>> + u64 ret; >>>> + >>>> + if (!cgroup_lock_live_group(cgrp)) >>>> + return -ENODEV; >>> >>> Why is cgroup_lock_live_cgroup() needed here? Does it protect updates >>> to sg->tcp_max_memory? >> >> No, that is not my understanding. My understanding is this lock is >> needed to protect against the cgroup just disappearing under our nose. >> > > Hm. reference count of dentry for cgroup isn't enough ? > > Thanks, > -Kame > think think think think think think... Yeah, I guess it is.
| |