}
#endif
-static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
- struct zone *zone,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
-{
- struct mem_cgroup *victim = NULL;
- int total = 0;
- int loop = 0;
- unsigned long excess;
- unsigned long nr_scanned;
- struct mem_cgroup_reclaim_cookie reclaim = {
- .zone = zone,
- .priority = 0,
- };
-
- excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
-
- while (1) {
- victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
- if (!victim) {
- loop++;
- 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)
- 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))
- break;
- }
- continue;
- }
- if (!mem_cgroup_reclaimable(victim, false))
- continue;
- total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
- zone, &nr_scanned);
- *total_scanned += nr_scanned;
- if (!res_counter_soft_limit_excess(&root_memcg->res))
- break;
+/*
+ * A group is eligible for the soft limit reclaim if it is
+ * a) is over its soft limit
+ * b) any parent up the hierarchy is over its soft limit
+ */
+bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *parent = memcg;
+
+ if (res_counter_soft_limit_excess(&memcg->res))
+ return true;
+
+ /*
+ * If any parent up the hierarchy is over its soft limit then we
+ * have to obey and reclaim from this group as well.
+ */
+ while((parent = parent_mem_cgroup(parent))) {
+ if (res_counter_soft_limit_excess(&parent->res))
+ return true;
}
- mem_cgroup_iter_break(root_memcg, victim);
- return total;
+
+ return false;
}
/*
return ret;
}
-unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
- gfp_t gfp_mask,
- unsigned long *total_scanned)
-{
- 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;
- unsigned long nr_scanned;
-
- 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;
-
- nr_scanned = 0;
- reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
- gfp_mask, &nr_scanned);
- nr_reclaimed += reclaimed;
- *total_scanned += nr_scanned;
- 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->memcg->css);
- else /* next_mz == NULL or other memcg */
- break;
- } while (1);
- }
- __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
- excess = res_counter_soft_limit_excess(&mz->memcg->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->memcg, mz, mctz, excess);
- spin_unlock(&mctz->lock);
- css_put(&mz->memcg->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->memcg->css);
- return nr_reclaimed;
-}
-
/**
* mem_cgroup_force_empty_list - clears LRU of a group
* @memcg: group to clear
projects / deliverable / linux.git / blobdiff