Hi Johannes:
Thank you for the patchset, and i will definitely spend time read them
through later today.
Also, I have a patchset which implements the round-robin soft_limit
reclaim as we discussed in LSF. Before I read through this set, i
don't know if we are making the similar approach or not. My
implementation is the first step only replace the RB-tree based
soft_limit reclaim to link_list round-robin. Feel free to throw
comment on that.
--Ying
On Thu, May 12, 2011 at 7:53 AM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> The current soft limit reclaim algorithm entered from kswapd. It
> selects the memcg that exceeds its soft limit the most in absolute
> bytes and reclaims from it most aggressively (priority 0).
>
> This has several disadvantages:
>
> 1. because of the aggressiveness, kswapd can be stalled on a
> memcg that is hard to reclaim for a long time before going for
> other pages.
>
> 2. it only considers the biggest violator (in absolute byes!)
> and does not put extra pressure on other memcgs in excess.
>
> 3. it needs a ton of code to quickly find the target
>
> This patch removes all the explicit soft limit target selection and
> instead hooks into the hierarchical memcg walk that is done by direct
> reclaim and kswapd balancing. If it encounters a memcg that exceeds
> its soft limit, or contributes to the soft limit excess in one of its
> hierarchy parents, it scans the memcg one priority level below the
> current reclaim priority.
>
> 1. the primary goal is to reclaim pages, not to punish soft
> limit violators at any price
>
> 2. increased pressure is applied to all violators, not just
> the biggest one
>
> 3. the soft limit is no longer only meaningful on global
> memory pressure, but considered for any hierarchical reclaim.
> This means that even for hard limit reclaim, the children in
> excess of their soft limit experience more pressure compared
> to their siblings
>
> 4. direct reclaim now also applies more pressure on memcgs in
> soft limit excess, not only kswapd
>
> 5. the implementation is only a few lines of straight-forward
> code
>
> RFC: since there is no longer a reliable way of counting the pages
> reclaimed solely because of an exceeding soft limit, this patch
> conflicts with Ying's exporting of exactly this number to userspace.
>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> ---
> include/linux/memcontrol.h | 16 +-
> include/linux/swap.h | 4 -
> mm/memcontrol.c | 450 +++-----------------------------------------
> mm/vmscan.c | 48 +-----
> 4 files changed, 34 insertions(+), 484 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 65163c2..b0c7323 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -99,6 +99,7 @@ extern void mem_cgroup_end_migration(struct mem_cgroup *mem,
> * For memory reclaim.
> */
> void mem_cgroup_hierarchy_walk(struct mem_cgroup *, struct mem_cgroup **);
> +bool mem_cgroup_soft_limit_exceeded(struct mem_cgroup *, struct mem_cgroup *);
> void mem_cgroup_count_reclaim(struct mem_cgroup *, bool, bool,
> unsigned long, unsigned long);
> int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg);
> @@ -140,8 +141,6 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
> mem_cgroup_update_page_stat(page, idx, -1);
> }
>
> -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
> - gfp_t gfp_mask);
> u64 mem_cgroup_get_limit(struct mem_cgroup *mem);
>
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> @@ -294,6 +293,12 @@ static inline void mem_cgroup_hierarchy_walk(struct mem_cgroup *start,
> *iter = start;
> }
>
> +static inline bool mem_cgroup_soft_limit_exceeded(struct mem_cgroup *root,
> + struct mem_cgroup *mem)
> +{
> + return 0;
> +}
> +
> static inline void mem_cgroup_count_reclaim(struct mem_cgroup *mem,
> bool kswapd, bool hierarchy,
> unsigned long scanned,
> @@ -349,13 +354,6 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
> }
>
> static inline
> -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
> - gfp_t gfp_mask)
> -{
> - return 0;
> -}
> -
> -static inline
> u64 mem_cgroup_get_limit(struct mem_cgroup *mem)
> {
> return 0;
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index a5c6da5..885cf19 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -254,10 +254,6 @@ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
> extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
> gfp_t gfp_mask, bool noswap,
> unsigned int swappiness);
> -extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
> - gfp_t gfp_mask, bool noswap,
> - unsigned int swappiness,
> - struct zone *zone);
> extern int __isolate_lru_page(struct page *page, int mode, int file);
> extern unsigned long shrink_all_memory(unsigned long nr_pages);
> extern int vm_swappiness;
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f5d90ba..b0c6dd5 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -34,7 +34,6 @@
> #include <linux/rcupdate.h>
> #include <linux/limits.h>
> #include <linux/mutex.h>
> -#include <linux/rbtree.h>
> #include <linux/slab.h>
> #include <linux/swap.h>
> #include <linux/swapops.h>
> @@ -138,12 +137,6 @@ struct mem_cgroup_per_zone {
> unsigned long count[NR_LRU_LISTS];
>
> struct zone_reclaim_stat reclaim_stat;
> - struct rb_node tree_node; /* RB tree node */
> - unsigned long long usage_in_excess;/* Set to the value by which */
> - /* the soft limit is exceeded*/
> - bool on_tree;
> - struct mem_cgroup *mem; /* Back pointer, we cannot */
> - /* use container_of */
> };
> /* Macro for accessing counter */
> #define MEM_CGROUP_ZSTAT(mz, idx) ((mz)->count[(idx)])
> @@ -156,26 +149,6 @@ struct mem_cgroup_lru_info {
> struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
> };
>
> -/*
> - * Cgroups above their limits are maintained in a RB-Tree, independent of
> - * their hierarchy representation
> - */
> -
> -struct mem_cgroup_tree_per_zone {
> - struct rb_root rb_root;
> - spinlock_t lock;
> -};
> -
> -struct mem_cgroup_tree_per_node {
> - struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
> -};
> -
> -struct mem_cgroup_tree {
> - struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
> -};
> -
> -static struct mem_cgroup_tree soft_limit_tree __read_mostly;
> -
> struct mem_cgroup_threshold {
> struct eventfd_ctx *eventfd;
> u64 threshold;
> @@ -323,12 +296,7 @@ static bool move_file(void)
> &mc.to->move_charge_at_immigrate);
> }
>
> -/*
> - * Maximum loops in mem_cgroup_soft_reclaim(), used for soft
> - * limit reclaim to prevent infinite loops, if they ever occur.
> - */
> #define MEM_CGROUP_MAX_RECLAIM_LOOPS (100)
> -#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS (2)
>
> enum charge_type {
> MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
> @@ -375,164 +343,6 @@ page_cgroup_zoneinfo(struct mem_cgroup *mem, struct page *page)
> return mem_cgroup_zoneinfo(mem, nid, zid);
> }
>
> -static struct mem_cgroup_tree_per_zone *
> -soft_limit_tree_node_zone(int nid, int zid)
> -{
> - return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
> -}
> -
> -static struct mem_cgroup_tree_per_zone *
> -soft_limit_tree_from_page(struct page *page)
> -{
> - int nid = page_to_nid(page);
> - int zid = page_zonenum(page);
> -
> - return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
> -}
> -
> -static void
> -__mem_cgroup_insert_exceeded(struct mem_cgroup *mem,
> - struct mem_cgroup_per_zone *mz,
> - struct mem_cgroup_tree_per_zone *mctz,
> - unsigned long long new_usage_in_excess)
> -{
> - struct rb_node **p = &mctz->rb_root.rb_node;
> - struct rb_node *parent = NULL;
> - struct mem_cgroup_per_zone *mz_node;
> -
> - if (mz->on_tree)
> - return;
> -
> - mz->usage_in_excess = new_usage_in_excess;
> - if (!mz->usage_in_excess)
> - return;
> - while (*p) {
> - parent = *p;
> - mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
> - tree_node);
> - if (mz->usage_in_excess < mz_node->usage_in_excess)
> - p = &(*p)->rb_left;
> - /*
> - * We can't avoid mem cgroups that are over their soft
> - * limit by the same amount
> - */
> - else if (mz->usage_in_excess >= mz_node->usage_in_excess)
> - p = &(*p)->rb_right;
> - }
> - rb_link_node(&mz->tree_node, parent, p);
> - rb_insert_color(&mz->tree_node, &mctz->rb_root);
> - mz->on_tree = true;
> -}
> -
> -static void
> -__mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
> - struct mem_cgroup_per_zone *mz,
> - struct mem_cgroup_tree_per_zone *mctz)
> -{
> - if (!mz->on_tree)
> - return;
> - rb_erase(&mz->tree_node, &mctz->rb_root);
> - mz->on_tree = false;
> -}
> -
> -static void
> -mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
> - struct mem_cgroup_per_zone *mz,
> - struct mem_cgroup_tree_per_zone *mctz)
> -{
> - spin_lock(&mctz->lock);
> - __mem_cgroup_remove_exceeded(mem, mz, mctz);
> - spin_unlock(&mctz->lock);
> -}
> -
> -
> -static void mem_cgroup_update_tree(struct mem_cgroup *mem, struct page *page)
> -{
> - unsigned long long excess;
> - struct mem_cgroup_per_zone *mz;
> - struct mem_cgroup_tree_per_zone *mctz;
> - int nid = page_to_nid(page);
> - int zid = page_zonenum(page);
> - mctz = soft_limit_tree_from_page(page);
> -
> - /*
> - * Necessary to update all ancestors when hierarchy is used.
> - * because their event counter is not touched.
> - */
> - for (; mem; mem = parent_mem_cgroup(mem)) {
> - mz = mem_cgroup_zoneinfo(mem, nid, zid);
> - excess = res_counter_soft_limit_excess(&mem->res);
> - /*
> - * We have to update the tree if mz is on RB-tree or
> - * mem is over its softlimit.
> - */
> - if (excess || mz->on_tree) {
> - spin_lock(&mctz->lock);
> - /* if on-tree, remove it */
> - if (mz->on_tree)
> - __mem_cgroup_remove_exceeded(mem, mz, mctz);
> - /*
> - * Insert again. mz->usage_in_excess will be updated.
> - * If excess is 0, no tree ops.
> - */
> - __mem_cgroup_insert_exceeded(mem, mz, mctz, excess);
> - spin_unlock(&mctz->lock);
> - }
> - }
> -}
> -
> -static void mem_cgroup_remove_from_trees(struct mem_cgroup *mem)
> -{
> - int node, zone;
> - struct mem_cgroup_per_zone *mz;
> - struct mem_cgroup_tree_per_zone *mctz;
> -
> - for_each_node_state(node, N_POSSIBLE) {
> - for (zone = 0; zone < MAX_NR_ZONES; zone++) {
> - mz = mem_cgroup_zoneinfo(mem, node, zone);
> - mctz = soft_limit_tree_node_zone(node, zone);
> - mem_cgroup_remove_exceeded(mem, mz, mctz);
> - }
> - }
> -}
> -
> -static struct mem_cgroup_per_zone *
> -__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
> -{
> - struct rb_node *rightmost = NULL;
> - struct mem_cgroup_per_zone *mz;
> -
> -retry:
> - mz = NULL;
> - rightmost = rb_last(&mctz->rb_root);
> - if (!rightmost)
> - goto done; /* Nothing to reclaim from */
> -
> - mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
> - /*
> - * Remove the node now but someone else can add it back,
> - * we will to add it back at the end of reclaim to its correct
> - * position in the tree.
> - */
> - __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
> - if (!res_counter_soft_limit_excess(&mz->mem->res) ||
> - !css_tryget(&mz->mem->css))
> - goto retry;
> -done:
> - return mz;
> -}
> -
> -static struct mem_cgroup_per_zone *
> -mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
> -{
> - struct mem_cgroup_per_zone *mz;
> -
> - spin_lock(&mctz->lock);
> - mz = __mem_cgroup_largest_soft_limit_node(mctz);
> - spin_unlock(&mctz->lock);
> - return mz;
> -}
> -
> /*
> * Implementation Note: reading percpu statistics for memcg.
> *
> @@ -570,15 +380,6 @@ static long mem_cgroup_read_stat(struct mem_cgroup *mem,
> return val;
> }
>
> -static long mem_cgroup_local_usage(struct mem_cgroup *mem)
> -{
> - long ret;
> -
> - ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
> - ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
> - return ret;
> -}
> -
> static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
> bool charge)
> {
> @@ -699,7 +500,6 @@ static void memcg_check_events(struct mem_cgroup *mem, struct page *page)
> __mem_cgroup_target_update(mem, MEM_CGROUP_TARGET_THRESH);
> if (unlikely(__memcg_event_check(mem,
> MEM_CGROUP_TARGET_SOFTLIMIT))){
> - mem_cgroup_update_tree(mem, page);
> __mem_cgroup_target_update(mem,
> MEM_CGROUP_TARGET_SOFTLIMIT);
> }
> @@ -1380,6 +1180,29 @@ void mem_cgroup_hierarchy_walk(struct mem_cgroup *start,
> *iter = mem;
> }
>
> +bool mem_cgroup_soft_limit_exceeded(struct mem_cgroup *root,
> + struct mem_cgroup *mem)
> +{
> + /* root_mem_cgroup never exceeds its soft limit */
> + if (!mem)
> + return false;
> + if (!root)
> + root = root_mem_cgroup;
> + /*
> + * See whether the memcg in question exceeds its soft limit
> + * directly, or contributes to the soft limit excess in the
> + * hierarchy below the given root.
> + */
> + while (mem != root) {
> + if (res_counter_soft_limit_excess(&mem->res))
> + return true;
> + if (!mem->use_hierarchy)
> + break;
> + mem = mem_cgroup_from_cont(mem->css.cgroup->parent);
> + }
> + return false;
> +}
> +
> static unsigned long mem_cgroup_target_reclaim(struct mem_cgroup *mem,
> gfp_t gfp_mask,
> bool noswap,
> @@ -1411,114 +1234,6 @@ static unsigned long mem_cgroup_target_reclaim(struct mem_cgroup *mem,
> }
>
> /*
> - * Visit the first child (need not be the first child as per the ordering
> - * of the cgroup list, since we track last_scanned_child) of @mem and use
> - * that to reclaim free pages from.
> - */
> -static struct mem_cgroup *
> -mem_cgroup_select_victim(struct mem_cgroup *root_mem)
> -{
> - struct mem_cgroup *ret = NULL;
> - struct cgroup_subsys_state *css;
> - int nextid, found;
> -
> - if (!root_mem->use_hierarchy) {
> - css_get(&root_mem->css);
> - ret = root_mem;
> - }
> -
> - while (!ret) {
> - rcu_read_lock();
> - nextid = root_mem->last_scanned_child + 1;
> - css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css,
> - &found);
> - if (css && css_tryget(css))
> - ret = container_of(css, struct mem_cgroup, css);
> -
> - rcu_read_unlock();
> - /* Updates scanning parameter */
> - if (!css) {
> - /* this means start scan from ID:1 */
> - root_mem->last_scanned_child = 0;
> - } else
> - root_mem->last_scanned_child = found;
> - }
> -
> - return ret;
> -}
> -
> -/*
> - * Scan the hierarchy if needed to reclaim memory. We remember the last child
> - * we reclaimed from, so that we don't end up penalizing one child extensively
> - * based on its position in the children list.
> - *
> - * root_mem is the original ancestor that we've been reclaim from.
> - *
> - * We give up and return to the caller when we visit root_mem twice.
> - * (other groups can be removed while we're walking....)
> - */
> -static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_mem,
> - struct zone *zone,
> - gfp_t gfp_mask)
> -{
> - struct mem_cgroup *victim;
> - int ret, total = 0;
> - int loop = 0;
> - unsigned long excess;
> - bool noswap = false;
> -
> - excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT;
> -
> - /* If memsw_is_minimum==1, swap-out is of-no-use. */
> - if (root_mem->memsw_is_minimum)
> - noswap = true;
> -
> - while (1) {
> - victim = mem_cgroup_select_victim(root_mem);
> - if (victim == root_mem) {
> - loop++;
> - if (loop >= 1)
> - drain_all_stock_async();
> - if (loop >= 2) {
> - /*
> - * If we have not been able to reclaim
> - * anything, it might because there are
> - * no reclaimable pages under this hierarchy
> - */
> - if (!total) {
> - css_put(&victim->css);
> - break;
> - }
> - /*
> - * We want to do more targeted reclaim.
> - * excess >> 2 is not to excessive so as to
> - * reclaim too much, nor too less that we keep
> - * coming back to reclaim from this cgroup
> - */
> - if (total >= (excess >> 2) ||
> - (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
> - css_put(&victim->css);
> - break;
> - }
> - }
> - }
> - if (!mem_cgroup_local_usage(victim)) {
> - /* this cgroup's local usage == 0 */
> - css_put(&victim->css);
> - continue;
> - }
> - /* we use swappiness of local cgroup */
> - ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
> - noswap, get_swappiness(victim), zone);
> - css_put(&victim->css);
> - total += ret;
> - if (!res_counter_soft_limit_excess(&root_mem->res))
> - return total;
> - }
> - return total;
> -}
> -
> -/*
> * Check OOM-Killer is already running under our hierarchy.
> * If someone is running, return false.
> */
> @@ -3291,94 +3006,6 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
> return ret;
> }
>
> -unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
> - gfp_t gfp_mask)
> -{
> - unsigned long nr_reclaimed = 0;
> - struct mem_cgroup_per_zone *mz, *next_mz = NULL;
> - unsigned long reclaimed;
> - int loop = 0;
> - struct mem_cgroup_tree_per_zone *mctz;
> - unsigned long long excess;
> -
> - if (order > 0)
> - return 0;
> -
> - mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
> - /*
> - * This loop can run a while, specially if mem_cgroup's continuously
> - * keep exceeding their soft limit and putting the system under
> - * pressure
> - */
> - do {
> - if (next_mz)
> - mz = next_mz;
> - else
> - mz = mem_cgroup_largest_soft_limit_node(mctz);
> - if (!mz)
> - break;
> -
> - reclaimed = mem_cgroup_soft_reclaim(mz->mem, zone, gfp_mask);
> - nr_reclaimed += reclaimed;
> - spin_lock(&mctz->lock);
> -
> - /*
> - * If we failed to reclaim anything from this memory cgroup
> - * it is time to move on to the next cgroup
> - */
> - next_mz = NULL;
> - if (!reclaimed) {
> - do {
> - /*
> - * Loop until we find yet another one.
> - *
> - * By the time we get the soft_limit lock
> - * again, someone might have aded the
> - * group back on the RB tree. Iterate to
> - * make sure we get a different mem.
> - * mem_cgroup_largest_soft_limit_node returns
> - * NULL if no other cgroup is present on
> - * the tree
> - */
> - next_mz =
> - __mem_cgroup_largest_soft_limit_node(mctz);
> - if (next_mz == mz) {
> - css_put(&next_mz->mem->css);
> - next_mz = NULL;
> - } else /* next_mz == NULL or other memcg */
> - break;
> - } while (1);
> - }
> - __mem_cgroup_remove_exceeded(mz->mem, mz, mctz);
> - excess = res_counter_soft_limit_excess(&mz->mem->res);
> - /*
> - * One school of thought says that we should not add
> - * back the node to the tree if reclaim returns 0.
> - * But our reclaim could return 0, simply because due
> - * to priority we are exposing a smaller subset of
> - * memory to reclaim from. Consider this as a longer
> - * term TODO.
> - */
> - /* If excess == 0, no tree ops */
> - __mem_cgroup_insert_exceeded(mz->mem, mz, mctz, excess);
> - spin_unlock(&mctz->lock);
> - css_put(&mz->mem->css);
> - loop++;
> - /*
> - * Could not reclaim anything and there are no more
> - * mem cgroups to try or we seem to be looping without
> - * reclaiming anything.
> - */
> - if (!nr_reclaimed &&
> - (next_mz == NULL ||
> - loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
> - break;
> - } while (!nr_reclaimed);
> - if (next_mz)
> - css_put(&next_mz->mem->css);
> - return nr_reclaimed;
> -}
> -
> /*
> * This routine traverse page_cgroup in given list and drop them all.
> * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
> @@ -4449,9 +4076,6 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
> mz = &pn->zoneinfo[zone];
> for_each_lru(l)
> INIT_LIST_HEAD(&mz->lruvec.lists[l]);
> - mz->usage_in_excess = 0;
> - mz->on_tree = false;
> - mz->mem = mem;
> }
> return 0;
> }
> @@ -4504,7 +4128,6 @@ static void __mem_cgroup_free(struct mem_cgroup *mem)
> {
> int node;
>
> - mem_cgroup_remove_from_trees(mem);
> free_css_id(&mem_cgroup_subsys, &mem->css);
>
> for_each_node_state(node, N_POSSIBLE)
> @@ -4559,31 +4182,6 @@ static void __init enable_swap_cgroup(void)
> }
> #endif
>
> -static int mem_cgroup_soft_limit_tree_init(void)
> -{
> - struct mem_cgroup_tree_per_node *rtpn;
> - struct mem_cgroup_tree_per_zone *rtpz;
> - int tmp, node, zone;
> -
> - for_each_node_state(node, N_POSSIBLE) {
> - tmp = node;
> - if (!node_state(node, N_NORMAL_MEMORY))
> - tmp = -1;
> - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
> - if (!rtpn)
> - return 1;
> -
> - soft_limit_tree.rb_tree_per_node[node] = rtpn;
> -
> - for (zone = 0; zone < MAX_NR_ZONES; zone++) {
> - rtpz = &rtpn->rb_tree_per_zone[zone];
> - rtpz->rb_root = RB_ROOT;
> - spin_lock_init(&rtpz->lock);
> - }
> - }
> - return 0;
> -}
> -
> static struct cgroup_subsys_state * __ref
> mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
> {
> @@ -4605,8 +4203,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
> enable_swap_cgroup();
> parent = NULL;
> root_mem_cgroup = mem;
> - if (mem_cgroup_soft_limit_tree_init())
> - goto free_out;
> for_each_possible_cpu(cpu) {
> struct memcg_stock_pcp *stock =
> &per_cpu(memcg_stock, cpu);
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 0381a5d..2b701e0 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1937,10 +1937,13 @@ static void shrink_zone(int priority, struct zone *zone,
> do {
> unsigned long reclaimed = sc->nr_reclaimed;
> unsigned long scanned = sc->nr_scanned;
> + int epriority = priority;
>
> mem_cgroup_hierarchy_walk(root, &mem);
> sc->current_memcg = mem;
> - do_shrink_zone(priority, zone, sc);
> + if (mem_cgroup_soft_limit_exceeded(root, mem))
> + epriority -= 1;
> + do_shrink_zone(epriority, zone, sc);
> mem_cgroup_count_reclaim(mem, current_is_kswapd(),
> mem != root, /* limit or hierarchy? */
> sc->nr_scanned - scanned,
> @@ -2153,42 +2156,6 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
> }
>
> #ifdef CONFIG_CGROUP_MEM_RES_CTLR
> -
> -unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
> - gfp_t gfp_mask, bool noswap,
> - unsigned int swappiness,
> - struct zone *zone)
> -{
> - struct scan_control sc = {
> - .nr_to_reclaim = SWAP_CLUSTER_MAX,
> - .may_writepage = !laptop_mode,
> - .may_unmap = 1,
> - .may_swap = !noswap,
> - .swappiness = swappiness,
> - .order = 0,
> - .memcg = mem,
> - };
> - sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
> - (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
> -
> - trace_mm_vmscan_memcg_softlimit_reclaim_begin(0,
> - sc.may_writepage,
> - sc.gfp_mask);
> -
> - /*
> - * NOTE: Although we can get the priority field, using it
> - * here is not a good idea, since it limits the pages we can scan.
> - * if we don't reclaim here, the shrink_zone from balance_pgdat
> - * will pick up pages from other mem cgroup's as well. We hack
> - * the priority and make it zero.
> - */
> - do_shrink_zone(0, zone, &sc);
> -
> - trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
> -
> - return sc.nr_reclaimed;
> -}
> -
> unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
> gfp_t gfp_mask,
> bool noswap,
> @@ -2418,13 +2385,6 @@ loop_again:
> continue;
>
> sc.nr_scanned = 0;
> -
> - /*
> - * Call soft limit reclaim before calling shrink_zone.
> - * For now we ignore the return value
> - */
> - mem_cgroup_soft_limit_reclaim(zone, order, sc.gfp_mask);
> -
> /*
> * We put equal pressure on every zone, unless
> * one zone has way too many pages free
> --
> 1.7.5.1
>
>
--
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