memcg: add file-based RSS accounting

Add file RSS tracking per memory cgroup

We currently don't track file RSS, the RSS we report is actually anon RSS.
 All the file mapped pages, come in through the page cache and get
accounted there.  This patch adds support for accounting file RSS pages.
It should

1. Help improve the metrics reported by the memory resource controller
2. Will form the basis for a future shared memory accounting heuristic
   that has been proposed by Kamezawa.

Unfortunately, we cannot rename the existing "rss" keyword used in
memory.stat to "anon_rss".  We however, add "mapped_file" data and hope to
educate the end user through documentation.

[hugh.dickins@tiscali.co.uk: fix mem_cgroup_update_mapped_file_stat oops]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.cn>
Cc: Paul Menage <menage@google.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 45add35dda1b5da25a1ad7d9ff88c94687cb3cad..e46a0734ab6e68c9f4df95ce5f9771923af392ea 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -117,7 +117,7 @@ static inline bool mem_cgroup_disabled(void)
 }
 
 extern bool mem_cgroup_oom_called(struct task_struct *task);
-
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val);
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 struct mem_cgroup;
 
@@ -271,6 +271,11 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
 }
 
+static inline void mem_cgroup_update_mapped_file_stat(struct page *page,
+                                                       int val)
+{
+}
+
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 70db6e0a5eece0a3a6d40f2089d91271968c3361..6f682901deb5dd32f798152bd6d7e0d7acb80764 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -62,7 +62,8 @@ enum mem_cgroup_stat_index {
         * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
         */
        MEM_CGROUP_STAT_CACHE,     /* # of pages charged as cache */
-       MEM_CGROUP_STAT_RSS,       /* # of pages charged as rss */
+       MEM_CGROUP_STAT_RSS,       /* # of pages charged as anon rss */
+       MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
        MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
        MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
 
@@ -900,6 +901,44 @@ static void record_last_oom(struct mem_cgroup *mem)
        mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
 }
 
+/*
+ * Currently used to update mapped file statistics, but the routine can be
+ * generalized to update other statistics as well.
+ */
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+{
+       struct mem_cgroup *mem;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
+       int cpu;
+       struct page_cgroup *pc;
+
+       if (!page_is_file_cache(page))
+               return;
+
+       pc = lookup_page_cgroup(page);
+       if (unlikely(!pc))
+               return;
+
+       lock_page_cgroup(pc);
+       mem = pc->mem_cgroup;
+       if (!mem)
+               goto done;
+
+       if (!PageCgroupUsed(pc))
+               goto done;
+
+       /*
+        * Preemption is already disabled, we don't need get_cpu()
+        */
+       cpu = smp_processor_id();
+       stat = &mem->stat;
+       cpustat = &stat->cpustat[cpu];
+
+       __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+done:
+       unlock_page_cgroup(pc);
+}
 
 /*
  * Unlike exported interface, "oom" parameter is added. if oom==true,
@@ -1098,6 +1137,10 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
        struct mem_cgroup_per_zone *from_mz, *to_mz;
        int nid, zid;
        int ret = -EBUSY;
+       struct page *page;
+       int cpu;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
 
        VM_BUG_ON(from == to);
        VM_BUG_ON(PageLRU(pc->page));
@@ -1118,6 +1161,23 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
 
        res_counter_uncharge(&from->res, PAGE_SIZE);
        mem_cgroup_charge_statistics(from, pc, false);
+
+       page = pc->page;
+       if (page_is_file_cache(page) && page_mapped(page)) {
+               cpu = smp_processor_id();
+               /* Update mapped_file data for mem_cgroup "from" */
+               stat = &from->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               -1);
+
+               /* Update mapped_file data for mem_cgroup "to" */
+               stat = &to->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               1);
+       }
+
        if (do_swap_account)
                res_counter_uncharge(&from->memsw, PAGE_SIZE);
        css_put(&from->css);
@@ -2046,6 +2106,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 enum {
        MCS_CACHE,
        MCS_RSS,
+       MCS_MAPPED_FILE,
        MCS_PGPGIN,
        MCS_PGPGOUT,
        MCS_INACTIVE_ANON,
@@ -2066,6 +2127,7 @@ struct {
 } memcg_stat_strings[NR_MCS_STAT] = {
        {"cache", "total_cache"},
        {"rss", "total_rss"},
+       {"mapped_file", "total_mapped_file"},
        {"pgpgin", "total_pgpgin"},
        {"pgpgout", "total_pgpgout"},
        {"inactive_anon", "total_inactive_anon"},
@@ -2086,6 +2148,8 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
        s->stat[MCS_CACHE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
        s->stat[MCS_RSS] += val * PAGE_SIZE;
+       val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
+       s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
        s->stat[MCS_PGPGIN] += val;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 4f31c9b3e940ab47e8f1b2f77cf7a7294904202a..672089d5819f681b473d99882b991c239115d70b 100644 (file)
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -99,6 +99,8 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
        unsigned long pfn = page_to_pfn(page);
        struct mem_section *section = __pfn_to_section(pfn);
 
+       if (!section->page_cgroup)
+               return NULL;
        return section->page_cgroup + pfn;
 }
 

diff --git a/mm/rmap.c b/mm/rmap.c
index c9ccc1a72dc32652827c0d6d81add911f59abbfb..836c6c63e1f2dbee16a922f7195da2f3ac237d83 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -703,8 +703,10 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-       if (atomic_inc_and_test(&page->_mapcount))
+       if (atomic_inc_and_test(&page->_mapcount)) {
                __inc_zone_page_state(page, NR_FILE_MAPPED);
+               mem_cgroup_update_mapped_file_stat(page, 1);
+       }
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -753,6 +755,7 @@ void page_remove_rmap(struct page *page)
                        mem_cgroup_uncharge_page(page);
                __dec_zone_page_state(page,
                        PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+               mem_cgroup_update_mapped_file_stat(page, -1);
                /*
                 * It would be tidy to reset the PageAnon mapping here,
                 * but that might overwrite a racing page_add_anon_rmap