memcg: do not recalculate section unnecessarily in init_section_page_cgroup
[linux-2.6.git] / mm / page_cgroup.c
1 #include <linux/mm.h>
2 #include <linux/mmzone.h>
3 #include <linux/bootmem.h>
4 #include <linux/bit_spinlock.h>
5 #include <linux/page_cgroup.h>
6 #include <linux/hash.h>
7 #include <linux/slab.h>
8 #include <linux/memory.h>
9 #include <linux/vmalloc.h>
10 #include <linux/cgroup.h>
11
12 static void __meminit
13 __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
14 {
15         pc->flags = 0;
16         pc->mem_cgroup = NULL;
17         pc->page = pfn_to_page(pfn);
18 }
19 static unsigned long total_usage;
20
21 #if !defined(CONFIG_SPARSEMEM)
22
23
24 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
25 {
26         pgdat->node_page_cgroup = NULL;
27 }
28
29 struct page_cgroup *lookup_page_cgroup(struct page *page)
30 {
31         unsigned long pfn = page_to_pfn(page);
32         unsigned long offset;
33         struct page_cgroup *base;
34
35         base = NODE_DATA(page_to_nid(page))->node_page_cgroup;
36         if (unlikely(!base))
37                 return NULL;
38
39         offset = pfn - NODE_DATA(page_to_nid(page))->node_start_pfn;
40         return base + offset;
41 }
42
43 static int __init alloc_node_page_cgroup(int nid)
44 {
45         struct page_cgroup *base, *pc;
46         unsigned long table_size;
47         unsigned long start_pfn, nr_pages, index;
48
49         start_pfn = NODE_DATA(nid)->node_start_pfn;
50         nr_pages = NODE_DATA(nid)->node_spanned_pages;
51
52         if (!nr_pages)
53                 return 0;
54
55         table_size = sizeof(struct page_cgroup) * nr_pages;
56
57         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
58                         table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
59         if (!base)
60                 return -ENOMEM;
61         for (index = 0; index < nr_pages; index++) {
62                 pc = base + index;
63                 __init_page_cgroup(pc, start_pfn + index);
64         }
65         NODE_DATA(nid)->node_page_cgroup = base;
66         total_usage += table_size;
67         return 0;
68 }
69
70 void __init page_cgroup_init(void)
71 {
72
73         int nid, fail;
74
75         if (mem_cgroup_subsys.disabled)
76                 return;
77
78         for_each_online_node(nid)  {
79                 fail = alloc_node_page_cgroup(nid);
80                 if (fail)
81                         goto fail;
82         }
83         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
84         printk(KERN_INFO "please try cgroup_disable=memory option if you"
85         " don't want\n");
86         return;
87 fail:
88         printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
89         printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
90         panic("Out of memory");
91 }
92
93 #else /* CONFIG_FLAT_NODE_MEM_MAP */
94
95 struct page_cgroup *lookup_page_cgroup(struct page *page)
96 {
97         unsigned long pfn = page_to_pfn(page);
98         struct mem_section *section = __pfn_to_section(pfn);
99
100         return section->page_cgroup + pfn;
101 }
102
103 /* __alloc_bootmem...() is protected by !slab_available() */
104 static int __init_refok init_section_page_cgroup(unsigned long pfn)
105 {
106         struct mem_section *section = __pfn_to_section(pfn);
107         struct page_cgroup *base, *pc;
108         unsigned long table_size;
109         int nid, index;
110
111         if (!section->page_cgroup) {
112                 nid = page_to_nid(pfn_to_page(pfn));
113                 table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
114                 if (slab_is_available()) {
115                         base = kmalloc_node(table_size, GFP_KERNEL, nid);
116                         if (!base)
117                                 base = vmalloc_node(table_size, nid);
118                 } else {
119                         base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
120                                 table_size,
121                                 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
122                 }
123         } else {
124                 /*
125                  * We don't have to allocate page_cgroup again, but
126                  * address of memmap may be changed. So, we have to initialize
127                  * again.
128                  */
129                 base = section->page_cgroup + pfn;
130                 table_size = 0;
131                 /* check address of memmap is changed or not. */
132                 if (base->page == pfn_to_page(pfn))
133                         return 0;
134         }
135
136         if (!base) {
137                 printk(KERN_ERR "page cgroup allocation failure\n");
138                 return -ENOMEM;
139         }
140
141         for (index = 0; index < PAGES_PER_SECTION; index++) {
142                 pc = base + index;
143                 __init_page_cgroup(pc, pfn + index);
144         }
145
146         section->page_cgroup = base - pfn;
147         total_usage += table_size;
148         return 0;
149 }
150 #ifdef CONFIG_MEMORY_HOTPLUG
151 void __free_page_cgroup(unsigned long pfn)
152 {
153         struct mem_section *ms;
154         struct page_cgroup *base;
155
156         ms = __pfn_to_section(pfn);
157         if (!ms || !ms->page_cgroup)
158                 return;
159         base = ms->page_cgroup + pfn;
160         if (is_vmalloc_addr(base)) {
161                 vfree(base);
162                 ms->page_cgroup = NULL;
163         } else {
164                 struct page *page = virt_to_page(base);
165                 if (!PageReserved(page)) { /* Is bootmem ? */
166                         kfree(base);
167                         ms->page_cgroup = NULL;
168                 }
169         }
170 }
171
172 int __meminit online_page_cgroup(unsigned long start_pfn,
173                         unsigned long nr_pages,
174                         int nid)
175 {
176         unsigned long start, end, pfn;
177         int fail = 0;
178
179         start = start_pfn & ~(PAGES_PER_SECTION - 1);
180         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
181
182         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
183                 if (!pfn_present(pfn))
184                         continue;
185                 fail = init_section_page_cgroup(pfn);
186         }
187         if (!fail)
188                 return 0;
189
190         /* rollback */
191         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
192                 __free_page_cgroup(pfn);
193
194         return -ENOMEM;
195 }
196
197 int __meminit offline_page_cgroup(unsigned long start_pfn,
198                 unsigned long nr_pages, int nid)
199 {
200         unsigned long start, end, pfn;
201
202         start = start_pfn & ~(PAGES_PER_SECTION - 1);
203         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
204
205         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
206                 __free_page_cgroup(pfn);
207         return 0;
208
209 }
210
211 static int __meminit page_cgroup_callback(struct notifier_block *self,
212                                unsigned long action, void *arg)
213 {
214         struct memory_notify *mn = arg;
215         int ret = 0;
216         switch (action) {
217         case MEM_GOING_ONLINE:
218                 ret = online_page_cgroup(mn->start_pfn,
219                                    mn->nr_pages, mn->status_change_nid);
220                 break;
221         case MEM_OFFLINE:
222                 offline_page_cgroup(mn->start_pfn,
223                                 mn->nr_pages, mn->status_change_nid);
224                 break;
225         case MEM_CANCEL_ONLINE:
226         case MEM_GOING_OFFLINE:
227                 break;
228         case MEM_ONLINE:
229         case MEM_CANCEL_OFFLINE:
230                 break;
231         }
232
233         if (ret)
234                 ret = notifier_from_errno(ret);
235         else
236                 ret = NOTIFY_OK;
237
238         return ret;
239 }
240
241 #endif
242
243 void __init page_cgroup_init(void)
244 {
245         unsigned long pfn;
246         int fail = 0;
247
248         if (mem_cgroup_subsys.disabled)
249                 return;
250
251         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {
252                 if (!pfn_present(pfn))
253                         continue;
254                 fail = init_section_page_cgroup(pfn);
255         }
256         if (fail) {
257                 printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
258                 panic("Out of memory");
259         } else {
260                 hotplug_memory_notifier(page_cgroup_callback, 0);
261         }
262         printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
263         printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
264         " want\n");
265 }
266
267 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
268 {
269         return;
270 }
271
272 #endif