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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2011-06-15 15:08:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-06-15 20:04:01 -0700
commit37573e8c718277103f61f03741bdc5606d31b07e (patch)
tree7142211508420a8ea90b8ae01bfa5ee93ffa1a44 /mm/page_cgroup.c
parent8957712710e045044e3c44375c6a87d7ffa17d51 (diff)
downloadlwn-37573e8c718277103f61f03741bdc5606d31b07e.tar.gz
lwn-37573e8c718277103f61f03741bdc5606d31b07e.zip
memcg: fix init_page_cgroup nid with sparsemem
Commit 21a3c9646873 ("memcg: allocate memory cgroup structures in local nodes") makes page_cgroup allocation as NUMA aware. But that caused a problem https://bugzilla.kernel.org/show_bug.cgi?id=36192. The problem was getting a NID from invalid struct pages, which was not initialized because it was out-of-node, out of [node_start_pfn, node_end_pfn) Now, with sparsemem, page_cgroup_init scans pfn from 0 to max_pfn. But this may scan a pfn which is not on any node and can access memmap which is not initialized. This makes page_cgroup_init() for SPARSEMEM node aware and remove a code to get nid from page->flags. (Then, we'll use valid NID always.) [akpm@linux-foundation.org: try to fix up comments] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_cgroup.c')
-rw-r--r--mm/page_cgroup.c71
1 files changed, 53 insertions, 18 deletions
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 74ccff61d1be..53bffc6c293e 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -162,13 +162,13 @@ static void free_page_cgroup(void *addr)
}
#endif
-static int __meminit init_section_page_cgroup(unsigned long pfn)
+static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
{
struct page_cgroup *base, *pc;
struct mem_section *section;
unsigned long table_size;
unsigned long nr;
- int nid, index;
+ int index;
nr = pfn_to_section_nr(pfn);
section = __nr_to_section(nr);
@@ -176,7 +176,6 @@ static int __meminit init_section_page_cgroup(unsigned long pfn)
if (section->page_cgroup)
return 0;
- nid = page_to_nid(pfn_to_page(pfn));
table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
base = alloc_page_cgroup(table_size, nid);
@@ -196,7 +195,11 @@ static int __meminit init_section_page_cgroup(unsigned long pfn)
pc = base + index;
init_page_cgroup(pc, nr);
}
-
+ /*
+ * The passed "pfn" may not be aligned to SECTION. For the calculation
+ * we need to apply a mask.
+ */
+ pfn &= PAGE_SECTION_MASK;
section->page_cgroup = base - pfn;
total_usage += table_size;
return 0;
@@ -225,10 +228,20 @@ int __meminit online_page_cgroup(unsigned long start_pfn,
start = start_pfn & ~(PAGES_PER_SECTION - 1);
end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
+ if (nid == -1) {
+ /*
+ * In this case, "nid" already exists and contains valid memory.
+ * "start_pfn" passed to us is a pfn which is an arg for
+ * online__pages(), and start_pfn should exist.
+ */
+ nid = pfn_to_nid(start_pfn);
+ VM_BUG_ON(!node_state(nid, N_ONLINE));
+ }
+
for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
if (!pfn_present(pfn))
continue;
- fail = init_section_page_cgroup(pfn);
+ fail = init_section_page_cgroup(pfn, nid);
}
if (!fail)
return 0;
@@ -284,25 +297,47 @@ static int __meminit page_cgroup_callback(struct notifier_block *self,
void __init page_cgroup_init(void)
{
unsigned long pfn;
- int fail = 0;
+ int nid;
if (mem_cgroup_disabled())
return;
- for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
- if (!pfn_present(pfn))
- continue;
- fail = init_section_page_cgroup(pfn);
- }
- if (fail) {
- printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
- panic("Out of memory");
- } else {
- hotplug_memory_notifier(page_cgroup_callback, 0);
+ for_each_node_state(nid, N_HIGH_MEMORY) {
+ unsigned long start_pfn, end_pfn;
+
+ start_pfn = node_start_pfn(nid);
+ end_pfn = node_end_pfn(nid);
+ /*
+ * start_pfn and end_pfn may not be aligned to SECTION and the
+ * page->flags of out of node pages are not initialized. So we
+ * scan [start_pfn, the biggest section's pfn < end_pfn) here.
+ */
+ for (pfn = start_pfn;
+ pfn < end_pfn;
+ pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
+
+ if (!pfn_valid(pfn))
+ continue;
+ /*
+ * Nodes's pfns can be overlapping.
+ * We know some arch can have a nodes layout such as
+ * -------------pfn-------------->
+ * N0 | N1 | N2 | N0 | N1 | N2|....
+ */
+ if (pfn_to_nid(pfn) != nid)
+ continue;
+ if (init_section_page_cgroup(pfn, nid))
+ goto oom;
+ }
}
+ hotplug_memory_notifier(page_cgroup_callback, 0);
printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
- printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
- " want memory cgroups\n");
+ printk(KERN_INFO "please try 'cgroup_disable=memory' option if you "
+ "don't want memory cgroups\n");
+ return;
+oom:
+ printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
+ panic("Out of memory");
}
void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)