| Message ID | 20210105225817.1036378-11-shy828301@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Make shrinker's nr_deferred memcg aware | expand |
On 06.01.2021 01:58, Yang Shi wrote: > Now shrinker's nr_deferred is per memcg for memcg aware shrinkers, add to parent's > corresponding nr_deferred when memcg offline. > > Signed-off-by: Yang Shi <shy828301@gmail.com> > --- > include/linux/memcontrol.h | 1 + > mm/memcontrol.c | 1 + > mm/vmscan.c | 29 +++++++++++++++++++++++++++++ > 3 files changed, 31 insertions(+) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 5599082df623..d1e52e916cc2 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -1586,6 +1586,7 @@ extern int memcg_alloc_shrinker_info(struct mem_cgroup *memcg); > extern void memcg_free_shrinker_info(struct mem_cgroup *memcg); > extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > int nid, int shrinker_id); > +extern void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg); > #else > #define mem_cgroup_sockets_enabled 0 > static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 126f1fd550c8..19e555675582 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -5284,6 +5284,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) > page_counter_set_low(&memcg->memory, 0); > > memcg_offline_kmem(memcg); > + memcg_reparent_shrinker_deferred(memcg); > wb_memcg_offline(memcg); > > drain_all_stock(memcg); > diff --git a/mm/vmscan.c b/mm/vmscan.c > index d9795fb0f1c5..71056057d26d 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -396,6 +396,35 @@ static long set_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, > return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); > } > > +void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg) > +{ > + int i, nid; > + long nr; > + struct mem_cgroup *parent; > + struct memcg_shrinker_info *child_info, *parent_info; > + > + parent = parent_mem_cgroup(memcg); > + if (!parent) > + parent = root_mem_cgroup; > + > + /* Prevent from concurrent shrinker_info expand */ > + down_read(&shrinker_rwsem); > + for_each_node(nid) { > + child_info = rcu_dereference_protected( > + memcg->nodeinfo[nid]->shrinker_info, > + true); > + parent_info = rcu_dereference_protected( > + parent->nodeinfo[nid]->shrinker_info, > + true); Simple assignment can't take such lots of space, we have to do something with that. Number of these rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, true) became too big, and we can't allow every of them takes 3 lines. We should introduce a short helper to dereferrence this, so we will be able to give out attention to really difficult logic instead of wasting it on parsing this. child_info = memcg_shrinker_info(memcg, nid); or child_info = memcg_shrinker_info_protected(memcg, nid); Both of them fit in single line. struct memcg_shrinker_info *memcg_shrinker_info_protected( struct mem_cgroup *memcg, int nid) { return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, lockdep_assert_held(&shrinker_rwsem)); } > + for (i = 0; i < shrinker_nr_max; i++) { > + nr = atomic_long_read(&child_info->nr_deferred[i]); > + atomic_long_add(nr, > + &parent_info->nr_deferred[i]); Why new line is here? In case of you merge it up, it will be even shorter then previous line. > + } > + } > + up_read(&shrinker_rwsem); > +} > + > static bool cgroup_reclaim(struct scan_control *sc) > { > return sc->target_mem_cgroup; >
On Wed, Jan 6, 2021 at 3:35 AM Kirill Tkhai <ktkhai@virtuozzo.com> wrote: > > On 06.01.2021 01:58, Yang Shi wrote: > > Now shrinker's nr_deferred is per memcg for memcg aware shrinkers, add to parent's > > corresponding nr_deferred when memcg offline. > > > > Signed-off-by: Yang Shi <shy828301@gmail.com> > > --- > > include/linux/memcontrol.h | 1 + > > mm/memcontrol.c | 1 + > > mm/vmscan.c | 29 +++++++++++++++++++++++++++++ > > 3 files changed, 31 insertions(+) > > > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > > index 5599082df623..d1e52e916cc2 100644 > > --- a/include/linux/memcontrol.h > > +++ b/include/linux/memcontrol.h > > @@ -1586,6 +1586,7 @@ extern int memcg_alloc_shrinker_info(struct mem_cgroup *memcg); > > extern void memcg_free_shrinker_info(struct mem_cgroup *memcg); > > extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > > int nid, int shrinker_id); > > +extern void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg); > > #else > > #define mem_cgroup_sockets_enabled 0 > > static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 126f1fd550c8..19e555675582 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -5284,6 +5284,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) > > page_counter_set_low(&memcg->memory, 0); > > > > memcg_offline_kmem(memcg); > > + memcg_reparent_shrinker_deferred(memcg); > > wb_memcg_offline(memcg); > > > > drain_all_stock(memcg); > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index d9795fb0f1c5..71056057d26d 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -396,6 +396,35 @@ static long set_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, > > return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); > > } > > > > +void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg) > > +{ > > + int i, nid; > > + long nr; > > + struct mem_cgroup *parent; > > + struct memcg_shrinker_info *child_info, *parent_info; > > + > > + parent = parent_mem_cgroup(memcg); > > + if (!parent) > > + parent = root_mem_cgroup; > > + > > + /* Prevent from concurrent shrinker_info expand */ > > + down_read(&shrinker_rwsem); > > + for_each_node(nid) { > > + child_info = rcu_dereference_protected( > > + memcg->nodeinfo[nid]->shrinker_info, > > + true); > > + parent_info = rcu_dereference_protected( > > + parent->nodeinfo[nid]->shrinker_info, > > + true); > > Simple assignment can't take such lots of space, we have to do something with that. > > Number of these > > rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, true) > > became too big, and we can't allow every of them takes 3 lines. > > We should introduce a short helper to dereferrence this, so we will be able to give > out attention to really difficult logic instead of wasting it on parsing this. > > child_info = memcg_shrinker_info(memcg, nid); > or > child_info = memcg_shrinker_info_protected(memcg, nid); > > Both of them fit in single line. > > struct memcg_shrinker_info *memcg_shrinker_info_protected( > struct mem_cgroup *memcg, int nid) > { > return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, > lockdep_assert_held(&shrinker_rwsem)); > } Thanks for the suggestion, it makes sense to me. Will incorporate it in v4. > > > > + for (i = 0; i < shrinker_nr_max; i++) { > > + nr = atomic_long_read(&child_info->nr_deferred[i]); > > + atomic_long_add(nr, > > + &parent_info->nr_deferred[i]); > > Why new line is here? In case of you merge it up, it will be even shorter then previous line. Just keep in 80 lines. We could relax it. > > > + } > > + } > > + up_read(&shrinker_rwsem); > > +} > > + > > static bool cgroup_reclaim(struct scan_control *sc) > > { > > return sc->target_mem_cgroup; > > > >
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 5599082df623..d1e52e916cc2 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1586,6 +1586,7 @@ extern int memcg_alloc_shrinker_info(struct mem_cgroup *memcg); extern void memcg_free_shrinker_info(struct mem_cgroup *memcg); extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id); +extern void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg); #else #define mem_cgroup_sockets_enabled 0 static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 126f1fd550c8..19e555675582 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5284,6 +5284,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) page_counter_set_low(&memcg->memory, 0); memcg_offline_kmem(memcg); + memcg_reparent_shrinker_deferred(memcg); wb_memcg_offline(memcg); drain_all_stock(memcg); diff --git a/mm/vmscan.c b/mm/vmscan.c index d9795fb0f1c5..71056057d26d 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -396,6 +396,35 @@ static long set_nr_deferred_memcg(long nr, int nid, struct shrinker *shrinker, return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); } +void memcg_reparent_shrinker_deferred(struct mem_cgroup *memcg) +{ + int i, nid; + long nr; + struct mem_cgroup *parent; + struct memcg_shrinker_info *child_info, *parent_info; + + parent = parent_mem_cgroup(memcg); + if (!parent) + parent = root_mem_cgroup; + + /* Prevent from concurrent shrinker_info expand */ + down_read(&shrinker_rwsem); + for_each_node(nid) { + child_info = rcu_dereference_protected( + memcg->nodeinfo[nid]->shrinker_info, + true); + parent_info = rcu_dereference_protected( + parent->nodeinfo[nid]->shrinker_info, + true); + for (i = 0; i < shrinker_nr_max; i++) { + nr = atomic_long_read(&child_info->nr_deferred[i]); + atomic_long_add(nr, + &parent_info->nr_deferred[i]); + } + } + up_read(&shrinker_rwsem); +} + static bool cgroup_reclaim(struct scan_control *sc) { return sc->target_mem_cgroup;
Now shrinker's nr_deferred is per memcg for memcg aware shrinkers, add to parent's corresponding nr_deferred when memcg offline. Signed-off-by: Yang Shi <shy828301@gmail.com> --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 1 + mm/vmscan.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 31 insertions(+)