blob: 0993f5f36b011ec567e3b559f50bb4dafde90479 [file] [log] [blame]
Joonsoo Kim48c96a32014-12-12 16:56:01 -08001#include <linux/debugfs.h>
2#include <linux/mm.h>
3#include <linux/slab.h>
4#include <linux/uaccess.h>
5#include <linux/bootmem.h>
6#include <linux/stacktrace.h>
7#include <linux/page_owner.h>
8#include "internal.h"
9
10static bool page_owner_disabled = true;
11bool page_owner_inited __read_mostly;
12
Joonsoo Kim61cf5fe2014-12-12 16:56:04 -080013static void init_early_allocated_pages(void);
14
Joonsoo Kim48c96a32014-12-12 16:56:01 -080015static int early_page_owner_param(char *buf)
16{
17 if (!buf)
18 return -EINVAL;
19
20 if (strcmp(buf, "on") == 0)
21 page_owner_disabled = false;
22
23 return 0;
24}
25early_param("page_owner", early_page_owner_param);
26
27static bool need_page_owner(void)
28{
29 if (page_owner_disabled)
30 return false;
31
32 return true;
33}
34
35static void init_page_owner(void)
36{
37 if (page_owner_disabled)
38 return;
39
40 page_owner_inited = true;
Joonsoo Kim61cf5fe2014-12-12 16:56:04 -080041 init_early_allocated_pages();
Joonsoo Kim48c96a32014-12-12 16:56:01 -080042}
43
44struct page_ext_operations page_owner_ops = {
45 .need = need_page_owner,
46 .init = init_page_owner,
47};
48
49void __reset_page_owner(struct page *page, unsigned int order)
50{
51 int i;
52 struct page_ext *page_ext;
53
54 for (i = 0; i < (1 << order); i++) {
55 page_ext = lookup_page_ext(page + i);
56 __clear_bit(PAGE_EXT_OWNER, &page_ext->flags);
57 }
58}
59
60void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask)
61{
Sergei Rogachev94f759d62015-02-11 15:28:34 -080062 struct page_ext *page_ext = lookup_page_ext(page);
63 struct stack_trace trace = {
64 .nr_entries = 0,
65 .max_entries = ARRAY_SIZE(page_ext->trace_entries),
66 .entries = &page_ext->trace_entries[0],
67 .skip = 3,
68 };
Joonsoo Kim48c96a32014-12-12 16:56:01 -080069
Sergei Rogachev94f759d62015-02-11 15:28:34 -080070 save_stack_trace(&trace);
Joonsoo Kim48c96a32014-12-12 16:56:01 -080071
72 page_ext->order = order;
73 page_ext->gfp_mask = gfp_mask;
Sergei Rogachev94f759d62015-02-11 15:28:34 -080074 page_ext->nr_entries = trace.nr_entries;
Joonsoo Kim48c96a32014-12-12 16:56:01 -080075
76 __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
77}
78
79static ssize_t
80print_page_owner(char __user *buf, size_t count, unsigned long pfn,
81 struct page *page, struct page_ext *page_ext)
82{
83 int ret;
84 int pageblock_mt, page_mt;
85 char *kbuf;
Sergei Rogachev94f759d62015-02-11 15:28:34 -080086 struct stack_trace trace = {
87 .nr_entries = page_ext->nr_entries,
88 .entries = &page_ext->trace_entries[0],
89 };
Joonsoo Kim48c96a32014-12-12 16:56:01 -080090
91 kbuf = kmalloc(count, GFP_KERNEL);
92 if (!kbuf)
93 return -ENOMEM;
94
95 ret = snprintf(kbuf, count,
96 "Page allocated via order %u, mask 0x%x\n",
97 page_ext->order, page_ext->gfp_mask);
98
99 if (ret >= count)
100 goto err;
101
102 /* Print information relevant to grouping pages by mobility */
103 pageblock_mt = get_pfnblock_migratetype(page, pfn);
104 page_mt = gfpflags_to_migratetype(page_ext->gfp_mask);
105 ret += snprintf(kbuf + ret, count - ret,
106 "PFN %lu Block %lu type %d %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n",
107 pfn,
108 pfn >> pageblock_order,
109 pageblock_mt,
110 pageblock_mt != page_mt ? "Fallback" : " ",
111 PageLocked(page) ? "K" : " ",
112 PageError(page) ? "E" : " ",
113 PageReferenced(page) ? "R" : " ",
114 PageUptodate(page) ? "U" : " ",
115 PageDirty(page) ? "D" : " ",
116 PageLRU(page) ? "L" : " ",
117 PageActive(page) ? "A" : " ",
118 PageSlab(page) ? "S" : " ",
119 PageWriteback(page) ? "W" : " ",
120 PageCompound(page) ? "C" : " ",
121 PageSwapCache(page) ? "B" : " ",
122 PageMappedToDisk(page) ? "M" : " ");
123
124 if (ret >= count)
125 goto err;
126
Sergei Rogachev94f759d62015-02-11 15:28:34 -0800127 ret += snprint_stack_trace(kbuf + ret, count - ret, &trace, 0);
Joonsoo Kim48c96a32014-12-12 16:56:01 -0800128 if (ret >= count)
129 goto err;
130
131 ret += snprintf(kbuf + ret, count - ret, "\n");
132 if (ret >= count)
133 goto err;
134
135 if (copy_to_user(buf, kbuf, ret))
136 ret = -EFAULT;
137
138 kfree(kbuf);
139 return ret;
140
141err:
142 kfree(kbuf);
143 return -ENOMEM;
144}
145
146static ssize_t
147read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
148{
149 unsigned long pfn;
150 struct page *page;
151 struct page_ext *page_ext;
152
153 if (!page_owner_inited)
154 return -EINVAL;
155
156 page = NULL;
157 pfn = min_low_pfn + *ppos;
158
159 /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
160 while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0)
161 pfn++;
162
163 drain_all_pages(NULL);
164
165 /* Find an allocated page */
166 for (; pfn < max_pfn; pfn++) {
167 /*
168 * If the new page is in a new MAX_ORDER_NR_PAGES area,
169 * validate the area as existing, skip it if not
170 */
171 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) {
172 pfn += MAX_ORDER_NR_PAGES - 1;
173 continue;
174 }
175
176 /* Check for holes within a MAX_ORDER area */
177 if (!pfn_valid_within(pfn))
178 continue;
179
180 page = pfn_to_page(pfn);
181 if (PageBuddy(page)) {
182 unsigned long freepage_order = page_order_unsafe(page);
183
184 if (freepage_order < MAX_ORDER)
185 pfn += (1UL << freepage_order) - 1;
186 continue;
187 }
188
189 page_ext = lookup_page_ext(page);
190
191 /*
Joonsoo Kim61cf5fe2014-12-12 16:56:04 -0800192 * Some pages could be missed by concurrent allocation or free,
193 * because we don't hold the zone lock.
Joonsoo Kim48c96a32014-12-12 16:56:01 -0800194 */
195 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
196 continue;
197
198 /* Record the next PFN to read in the file offset */
199 *ppos = (pfn - min_low_pfn) + 1;
200
201 return print_page_owner(buf, count, pfn, page, page_ext);
202 }
203
204 return 0;
205}
206
Joonsoo Kim61cf5fe2014-12-12 16:56:04 -0800207static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
208{
209 struct page *page;
210 struct page_ext *page_ext;
211 unsigned long pfn = zone->zone_start_pfn, block_end_pfn;
212 unsigned long end_pfn = pfn + zone->spanned_pages;
213 unsigned long count = 0;
214
215 /* Scan block by block. First and last block may be incomplete */
216 pfn = zone->zone_start_pfn;
217
218 /*
219 * Walk the zone in pageblock_nr_pages steps. If a page block spans
220 * a zone boundary, it will be double counted between zones. This does
221 * not matter as the mixed block count will still be correct
222 */
223 for (; pfn < end_pfn; ) {
224 if (!pfn_valid(pfn)) {
225 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
226 continue;
227 }
228
229 block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
230 block_end_pfn = min(block_end_pfn, end_pfn);
231
232 page = pfn_to_page(pfn);
233
234 for (; pfn < block_end_pfn; pfn++) {
235 if (!pfn_valid_within(pfn))
236 continue;
237
238 page = pfn_to_page(pfn);
239
240 /*
241 * We are safe to check buddy flag and order, because
242 * this is init stage and only single thread runs.
243 */
244 if (PageBuddy(page)) {
245 pfn += (1UL << page_order(page)) - 1;
246 continue;
247 }
248
249 if (PageReserved(page))
250 continue;
251
252 page_ext = lookup_page_ext(page);
253
254 /* Maybe overraping zone */
255 if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
256 continue;
257
258 /* Found early allocated page */
259 set_page_owner(page, 0, 0);
260 count++;
261 }
262 }
263
264 pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
265 pgdat->node_id, zone->name, count);
266}
267
268static void init_zones_in_node(pg_data_t *pgdat)
269{
270 struct zone *zone;
271 struct zone *node_zones = pgdat->node_zones;
272 unsigned long flags;
273
274 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
275 if (!populated_zone(zone))
276 continue;
277
278 spin_lock_irqsave(&zone->lock, flags);
279 init_pages_in_zone(pgdat, zone);
280 spin_unlock_irqrestore(&zone->lock, flags);
281 }
282}
283
284static void init_early_allocated_pages(void)
285{
286 pg_data_t *pgdat;
287
288 drain_all_pages(NULL);
289 for_each_online_pgdat(pgdat)
290 init_zones_in_node(pgdat);
291}
292
Joonsoo Kim48c96a32014-12-12 16:56:01 -0800293static const struct file_operations proc_page_owner_operations = {
294 .read = read_page_owner,
295};
296
297static int __init pageowner_init(void)
298{
299 struct dentry *dentry;
300
301 if (!page_owner_inited) {
302 pr_info("page_owner is disabled\n");
303 return 0;
304 }
305
306 dentry = debugfs_create_file("page_owner", S_IRUSR, NULL,
307 NULL, &proc_page_owner_operations);
308 if (IS_ERR(dentry))
309 return PTR_ERR(dentry);
310
311 return 0;
312}
313module_init(pageowner_init)