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-rw-r--r--mm/memcontrol.c102
-rw-r--r--mm/vmscan.c10
2 files changed, 105 insertions, 7 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fc62c71..1520efd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -231,6 +231,11 @@ struct mem_cgroup {
* reclaimed from.
*/
int last_scanned_child;
+ int last_scanned_node;
+#if MAX_NUMNODES > 1
+ nodemask_t scan_nodes;
+ unsigned long next_scan_node_update;
+#endif
/*
* Should the accounting and control be hierarchical, per subtree?
*/
@@ -624,18 +629,27 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
preempt_enable();
}
+static unsigned long
+mem_cgroup_get_zonestat_node(struct mem_cgroup *mem, int nid, enum lru_list idx)
+{
+ struct mem_cgroup_per_zone *mz;
+ u64 total = 0;
+ int zid;
+
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ mz = mem_cgroup_zoneinfo(mem, nid, zid);
+ total += MEM_CGROUP_ZSTAT(mz, idx);
+ }
+ return total;
+}
static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
enum lru_list idx)
{
- int nid, zid;
- struct mem_cgroup_per_zone *mz;
+ int nid;
u64 total = 0;
for_each_online_node(nid)
- for (zid = 0; zid < MAX_NR_ZONES; zid++) {
- mz = mem_cgroup_zoneinfo(mem, nid, zid);
- total += MEM_CGROUP_ZSTAT(mz, idx);
- }
+ total += mem_cgroup_get_zonestat_node(mem, nid, idx);
return total;
}
@@ -1418,6 +1432,81 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem)
return ret;
}
+#if MAX_NUMNODES > 1
+
+/*
+ * Always updating the nodemask is not very good - even if we have an empty
+ * list or the wrong list here, we can start from some node and traverse all
+ * nodes based on the zonelist. So update the list loosely once per 10 secs.
+ *
+ */
+static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem)
+{
+ int nid;
+
+ if (time_after(mem->next_scan_node_update, jiffies))
+ return;
+
+ mem->next_scan_node_update = jiffies + 10*HZ;
+ /* make a nodemask where this memcg uses memory from */
+ mem->scan_nodes = node_states[N_HIGH_MEMORY];
+
+ for_each_node_mask(nid, node_states[N_HIGH_MEMORY]) {
+
+ if (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_FILE) ||
+ mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_FILE))
+ continue;
+
+ if (total_swap_pages &&
+ (mem_cgroup_get_zonestat_node(mem, nid, LRU_INACTIVE_ANON) ||
+ mem_cgroup_get_zonestat_node(mem, nid, LRU_ACTIVE_ANON)))
+ continue;
+ node_clear(nid, mem->scan_nodes);
+ }
+}
+
+/*
+ * Selecting a node where we start reclaim from. Because what we need is just
+ * reducing usage counter, start from anywhere is O,K. Considering
+ * memory reclaim from current node, there are pros. and cons.
+ *
+ * Freeing memory from current node means freeing memory from a node which
+ * we'll use or we've used. So, it may make LRU bad. And if several threads
+ * hit limits, it will see a contention on a node. But freeing from remote
+ * node means more costs for memory reclaim because of memory latency.
+ *
+ * Now, we use round-robin. Better algorithm is welcomed.
+ */
+int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
+{
+ int node;
+
+ mem_cgroup_may_update_nodemask(mem);
+ node = mem->last_scanned_node;
+
+ node = next_node(node, mem->scan_nodes);
+ if (node == MAX_NUMNODES)
+ node = first_node(mem->scan_nodes);
+ /*
+ * We call this when we hit limit, not when pages are added to LRU.
+ * No LRU may hold pages because all pages are UNEVICTABLE or
+ * memcg is too small and all pages are not on LRU. In that case,
+ * we use curret node.
+ */
+ if (unlikely(node == MAX_NUMNODES))
+ node = numa_node_id();
+
+ mem->last_scanned_node = node;
+ return node;
+}
+
+#else
+int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
+{
+ return 0;
+}
+#endif
+
/*
* 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
@@ -4606,6 +4695,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
res_counter_init(&mem->memsw, NULL);
}
mem->last_scanned_child = 0;
+ mem->last_scanned_node = MAX_NUMNODES;
INIT_LIST_HEAD(&mem->oom_notify);
if (parent)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 884ae08..b087587 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2226,6 +2226,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
{
struct zonelist *zonelist;
unsigned long nr_reclaimed;
+ int nid;
struct scan_control sc = {
.may_writepage = !laptop_mode,
.may_unmap = 1,
@@ -2242,7 +2243,14 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
.gfp_mask = sc.gfp_mask,
};
- zonelist = NODE_DATA(numa_node_id())->node_zonelists;
+ /*
+ * Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
+ * take care of from where we get pages. So the node where we start the
+ * scan does not need to be the current node.
+ */
+ nid = mem_cgroup_select_victim_node(mem_cont);
+
+ zonelist = NODE_DATA(nid)->node_zonelists;
trace_mm_vmscan_memcg_reclaim_begin(0,
sc.may_writepage,
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