Re: [PATCH 1/3] memcg: fix reclaimable lru check in memcg.
From: Michal Hocko <hidden>
Date: 2011-06-29 13:41:05
Also in:
lkml
On Tue 28-06-11 17:39:58, KAMEZAWA Hiroyuki wrote:
From b52bcd09843e903e5f184d0ee499909d072f3c8d Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki <redacted> Date: Tue, 28 Jun 2011 15:45:38 +0900 Subject: [PATCH 1/3] memcg: fix reclaimable lru check in memcg. Now, in mem_cgroup_hierarchical_reclaim(), mem_cgroup_local_usage() is used for checking whether the memcg contains reclaimable pages or not. If no pages in it, the routine skips it. But, mem_cgroup_local_usage() contains Unevictable pages and cannot handle "noswap" condition correctly. This doesn't work on a swapless system. This patch adds test_mem_cgroup_reclaimable() and replaces mem_cgroup_local_usage(). test_mem_cgroup_reclaimable() see LRU counter and returns correct answer to the caller. And this new function has "noswap" argument and can see only FILE LRU if necessary. Signed-off-by: KAMEZAWA Hiroyuki <redacted>
Reviewed-by: Michal Hocko <redacted> except for !CONFIG_NUMA issue - see bellow.
quoted hunk ↗ jump to hunk
@@ -1559,6 +1550,27 @@ mem_cgroup_select_victim(struct mem_cgroup *root_mem) return ret; } +/** test_mem_cgroup_node_reclaimable + * @mem: the target memcg + * @nid: the node ID to be checked. + * @noswap : specify true here if the user wants flle only information. + * + * This function returns whether the specified memcg contains any + * reclaimable pages on a node. Returns true if there are any reclaimable + * pages in the node. + */ +static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *mem, + int nid, bool noswap) +{ + if (mem_cgroup_node_nr_file_lru_pages(mem, nid)) + return true;
I do not see definition of mem_cgroup_node_nr_file_lru_pages for !MAX_NUMNODES==1 (resp. !CONFIG_NUMA) and you are calling this function also from that context.
quoted hunk ↗ jump to hunk
#if MAX_NUMNODES > 1 /*@@ -1580,15 +1592,8 @@ static void mem_cgroup_may_update_nodemask(struct mem_cgroup *mem) 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); + if (!test_mem_cgroup_node_reclaimable(mem, nid, false)) + node_clear(nid, mem->scan_nodes);
Nice clean up.
quoted hunk ↗ jump to hunk
@@ -1627,11 +1632,51 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *mem) return node; } +/* + * Check all nodes whether it contains reclaimable pages or not. + * For quick scan, we make use of scan_nodes. This will allow us to skip + * unused nodes. But scan_nodes is lazily updated and may not cotain + * enough new information. We need to do double check. + */ +bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap) +{ + int nid; + + /* + * quick check...making use of scan_node. + * We can skip unused nodes. + */ + if (!nodes_empty(mem->scan_nodes)) { + for (nid = first_node(mem->scan_nodes); + nid < MAX_NUMNODES; + nid = next_node(nid, mem->scan_nodes)) { + + if (test_mem_cgroup_node_reclaimable(mem, nid, noswap)) + return true; + } + } + /* + * Check rest of nodes. + */ + for_each_node_state(nid, N_HIGH_MEMORY) { + if (node_isset(nid, mem->scan_nodes)) + continue; + if (test_mem_cgroup_node_reclaimable(mem, nid, noswap)) + return true; + } + return false; +} + #else
This is #else if MAX_NUMNODES == 1 AFAICS
int mem_cgroup_select_victim_node(struct mem_cgroup *mem)
{
return 0;
}
+
+bool mem_cgroup_reclaimable(struct mem_cgroup *mem, bool noswap)
+{
+ return test_mem_cgroup_node_reclaimable(mem, 0, noswap);
+}
#endif-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>