Messages in this thread | | | Date | Sun, 2 Nov 2008 14:38:17 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [mm] [PATCH 4/4] Memory cgroup hierarchy feature selector |
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On Sun, 02 Nov 2008 00:19:02 +0530 Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> > Don't enable multiple hierarchy support by default. This patch introduces > a features element that can be set to enable the nested depth hierarchy > feature. This feature can only be enabled when there is just one cgroup > (the root cgroup). > Why the flag is for the whole system ? flag-per-subtree is of no use ?
Thanks, -Kame
> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> > --- > > mm/memcontrol.c | 38 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 37 insertions(+), 1 deletion(-) > > diff -puN mm/memcontrol.c~memcg-add-hierarchy-selector mm/memcontrol.c > --- linux-2.6.28-rc2/mm/memcontrol.c~memcg-add-hierarchy-selector 2008-11-02 00:15:00.000000000 +0530 > +++ linux-2.6.28-rc2-balbir/mm/memcontrol.c 2008-11-02 00:15:00.000000000 +0530 > @@ -40,6 +40,9 @@ > struct cgroup_subsys mem_cgroup_subsys __read_mostly; > #define MEM_CGROUP_RECLAIM_RETRIES 5 > > +static unsigned long mem_cgroup_features; > +#define MEM_CGROUP_FEAT_HIERARCHY 0x1 > + > /* > * Statistics for memory cgroup. > */ > @@ -1080,6 +1083,31 @@ out: > return ret; > } > > +static u64 mem_cgroup_feature_read(struct cgroup *cont, struct cftype *cft) > +{ > + return mem_cgroup_features; > +} > + > +static int mem_cgroup_feature_write(struct cgroup *cont, struct cftype *cft, > + u64 val) > +{ > + int retval = 0; > + struct cgroup *cgroup = init_mem_cgroup.css.cgroup; > + > + if (val & MEM_CGROUP_FEAT_HIERARCHY) { > + if (list_empty(&cgroup->children)) > + mem_cgroup_features |= MEM_CGROUP_FEAT_HIERARCHY; > + else > + retval = -EBUSY; > + } else { > + if (list_empty(&cgroup->children)) > + mem_cgroup_features &= ~MEM_CGROUP_FEAT_HIERARCHY; > + else > + retval = -EBUSY; > + } > + return retval; > +} > + > static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft) > { > return res_counter_read_u64(&mem_cgroup_from_cont(cont)->res, > @@ -1214,6 +1242,11 @@ static struct cftype mem_cgroup_files[] > .name = "stat", > .read_map = mem_control_stat_show, > }, > + { > + .name = "features", > + .write_u64 = mem_cgroup_feature_write, > + .read_u64 = mem_cgroup_feature_read, > + }, > }; > > static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node) > @@ -1292,7 +1325,10 @@ mem_cgroup_create(struct cgroup_subsys * > return ERR_PTR(-ENOMEM); > } > > - res_counter_init(&mem->res, parent ? &parent->res : NULL); > + if ((mem_cgroup_features & MEM_CGROUP_FEAT_HIERARCHY) && parent) > + res_counter_init(&mem->res, &parent->res); > + else > + res_counter_init(&mem->res, NULL); > > for_each_node_state(node, N_POSSIBLE) > if (alloc_mem_cgroup_per_zone_info(mem, node)) > _ > > -- > Balbir >
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