On Thu, Apr 14, 2011 at 6:40 PM, KAMEZAWA Hiroyuki < kamezawa.hiroyu@jp.fujitsu.com> wrote: > On Thu, 14 Apr 2011 15:54:28 -0700 > Ying Han wrote: > > > This add the API which exports per-memcg kswapd thread pid. The kswapd > > thread is named as "memcg_" + css_id, and the pid can be used to put > > kswapd thread into cpu cgroup later. > > > > $ mkdir /dev/cgroup/memory/A > > $ cat /dev/cgroup/memory/A/memory.kswapd_pid > > memcg_null 0 > > > > $ echo 500m >/dev/cgroup/memory/A/memory.limit_in_bytes > > $ echo 50m >/dev/cgroup/memory/A/memory.high_wmark_distance > > $ ps -ef | grep memcg > > root 6727 2 0 14:32 ? 00:00:00 [memcg_3] > > root 6729 6044 0 14:32 ttyS0 00:00:00 grep memcg > > > > $ cat memory.kswapd_pid > > memcg_3 6727 > > > > changelog v4..v3 > > 1. Add the API based on KAMAZAWA's request on patch v3. > > > > Signed-off-by: Ying Han > > Thank you. > > > --- > > include/linux/swap.h | 2 ++ > > mm/memcontrol.c | 33 +++++++++++++++++++++++++++++++++ > > mm/vmscan.c | 2 +- > > 3 files changed, 36 insertions(+), 1 deletions(-) > > > > diff --git a/include/linux/swap.h b/include/linux/swap.h > > index 319b800..2d3e21a 100644 > > --- a/include/linux/swap.h > > +++ b/include/linux/swap.h > > @@ -34,6 +34,8 @@ struct kswapd { > > }; > > > > int kswapd(void *p); > > +extern spinlock_t kswapds_spinlock; > > + > > /* > > * MAX_SWAPFILES defines the maximum number of swaptypes: things which > can > > * be swapped to. The swap type and the offset into that swap type are > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 1b23ff4..606b680 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -4493,6 +4493,35 @@ static int mem_cgroup_wmark_read(struct cgroup > *cgrp, > > return 0; > > } > > > > +static int mem_cgroup_kswapd_pid_read(struct cgroup *cgrp, > > + struct cftype *cft, struct cgroup_map_cb *cb) > > +{ > > + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); > > + struct task_struct *kswapd_thr = NULL; > > + struct kswapd *kswapd_p = NULL; > > + wait_queue_head_t *wait; > > + char name[TASK_COMM_LEN]; > > + pid_t pid = 0; > > + > > I think '0' is ... not very good. This '0' implies there is no kswapd. > But 0 is root pid. I have no idea. Do you have no concern ? > > Otherewise, the interface seems good. > Thank you for review. I will make the change for the pid on initializing to "-1". --Ying > > Reviewed-by: KAMEZAWA Hiroyuki > > > > > > + sprintf(name, "memcg_null"); > > + > > + spin_lock(&kswapds_spinlock); > > + wait = mem_cgroup_kswapd_wait(mem); > > + if (wait) { > > + kswapd_p = container_of(wait, struct kswapd, kswapd_wait); > > + kswapd_thr = kswapd_p->kswapd_task; > > + if (kswapd_thr) { > > + get_task_comm(name, kswapd_thr); > > + pid = kswapd_thr->pid; > > + } > > + } > > + spin_unlock(&kswapds_spinlock); > > + > > + cb->fill(cb, name, pid); > > + > > + return 0; > > +} > > + > > static int mem_cgroup_oom_control_read(struct cgroup *cgrp, > > struct cftype *cft, struct cgroup_map_cb *cb) > > { > > @@ -4610,6 +4639,10 @@ static struct cftype mem_cgroup_files[] = { > > .name = "reclaim_wmarks", > > .read_map = mem_cgroup_wmark_read, > > }, > > + { > > + .name = "kswapd_pid", > > + .read_map = mem_cgroup_kswapd_pid_read, > > + }, > > }; > > > > #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index c081112..df4e5dd 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -2249,7 +2249,7 @@ static bool pgdat_balanced(pg_data_t *pgdat, > unsigned long balanced_pages, > > return balanced_pages > (present_pages >> 2); > > } > > > > -static DEFINE_SPINLOCK(kswapds_spinlock); > > +DEFINE_SPINLOCK(kswapds_spinlock); > > #define is_node_kswapd(kswapd_p) (!(kswapd_p)->kswapd_mem) > > > > /* is kswapd sleeping prematurely? */ > > -- > > 1.7.3.1 > > > > -- > > To unsubscribe, send a message with 'unsubscribe linux-mm' in > > the body to majordomo@kvack.org. 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: email@kvack.org > > > >