2 * Copyright (C) 2013 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 #include <sys/types.h>
27 #include <pagemap/pagemap.h>
29 #define MAX_FILENAME 64
31 #define GROWTH_FACTOR 10
33 #define NO_PATTERN 0x100
48 size_t vaddr_len, vaddr_size;
54 struct ksm_page *pages;
58 static void usage(char *myname);
59 static int getprocname(pid_t pid, char *buf, int len);
60 static int read_pages(struct ksm_pages *kp, pm_map_t **maps, size_t num_maps, uint8_t pr_flags);
61 static void print_pages(struct ksm_pages *kp, uint8_t pr_flags);
62 static void free_pages(struct ksm_pages *kp, uint8_t pr_flags);
63 static bool is_pattern(uint8_t *data, size_t len);
64 static int cmp_pages(const void *a, const void *b);
65 extern uint32_t hashword(const uint32_t *, size_t, int32_t);
67 int main(int argc, char *argv[]) {
75 char cmdline[256]; // this must be within the range of int
77 int rc = EXIT_SUCCESS;
81 memset(&kp, 0, sizeof(kp));
85 int c = getopt(argc, argv, "hvsa");
94 pr_flags |= PR_SORTED;
97 pr_flags |= PR_VERBOSE;
103 fprintf(stderr, "unknown option: %c\n", optopt);
109 error = pm_kernel_create(&ker);
111 fprintf(stderr, "Error creating kernel interface -- "
112 "does this kernel have pagemap?\n");
116 if (pr_flags & PR_ALL) {
117 error = pm_kernel_pids(ker, &pids, &num_procs);
119 fprintf(stderr, "Error listing processes.\n");
123 if (optind != argc - 1) {
128 pids = malloc(sizeof(*pids));
130 fprintf(stderr, "Error allocating pid memory\n");
134 *pids = strtoul(argv[optind], NULL, 10);
136 fprintf(stderr, "Invalid PID\n");
141 if (getprocname(*pids, cmdline, sizeof(cmdline)) < 0) {
144 printf("%s (%u):\n", cmdline, *pids);
147 printf("Warning: this tool only compares the KSM CRCs of pages, there is a chance of "
150 for (i = 0; i < num_procs; i++) {
151 error = pm_process_create(ker, pids[i], &proc);
153 fprintf(stderr, "warning: could not create process interface for %d\n", pids[i]);
158 error = pm_process_maps(proc, &maps, &num_maps);
160 pm_process_destroy(proc);
161 fprintf(stderr, "warning: could not read process map for %d\n", pids[i]);
166 if (read_pages(&kp, maps, num_maps, pr_flags) < 0) {
168 pm_process_destroy(proc);
174 pm_process_destroy(proc);
177 if (pr_flags & PR_SORTED) {
178 qsort(kp.pages, kp.len, sizeof(*kp.pages), cmp_pages);
180 print_pages(&kp, pr_flags);
183 free_pages(&kp, pr_flags);
188 static int read_pages(struct ksm_pages *kp, pm_map_t **maps, size_t num_maps, uint8_t pr_flags) {
199 char filename[MAX_FILENAME];
203 struct ksm_page *cur_page;
209 pid = pm_process_pid(maps[0]->proc);
210 ker = maps[0]->proc->ker;
211 error = snprintf(filename, MAX_FILENAME, "/proc/%d/mem", pid);
212 if (error < 0 || error >= MAX_FILENAME) {
216 data = malloc(pm_kernel_pagesize(ker));
218 fprintf(stderr, "warning: not enough memory to malloc data buffer\n");
222 fd = open(filename, O_RDONLY);
224 fprintf(stderr, "warning: could not open %s\n", filename);
229 for (i = 0; i < num_maps; i++) {
230 error = pm_map_pagemap(maps[i], &pagemap, &map_len);
232 fprintf(stderr, "warning: could not read the pagemap of %d\n",
233 pm_process_pid(maps[i]->proc));
236 for (j = 0; j < map_len; j++) {
237 error = pm_kernel_flags(ker, pagemap[j], &flags);
239 fprintf(stderr, "warning: could not read flags for pfn at address 0x%016llx\n",
243 if (!(flags & PM_PAGE_KSM)) {
246 vaddr = pm_map_start(maps[i]) + j * pm_kernel_pagesize(ker);
247 off = lseek(fd, vaddr, SEEK_SET);
248 if (off == (off_t)-1) {
249 fprintf(stderr, "warning: could not lseek to 0x%08lx\n", vaddr);
252 len = read(fd, data, pm_kernel_pagesize(ker));
253 if (len != pm_kernel_pagesize(ker)) {
254 fprintf(stderr, "warning: could not read page at 0x%08lx\n", vaddr);
258 hash = hashword(data, pm_kernel_pagesize(ker) / sizeof(*data), 17);
260 for (k = 0; k < kp->len; k++) {
261 if (kp->pages[k].hash == hash) break;
265 if (kp->len == kp->size) {
266 struct ksm_page *tmp = realloc(kp->pages,
267 (kp->size + GROWTH_FACTOR) * sizeof(*kp->pages));
269 fprintf(stderr, "warning: not enough memory to realloc pages struct\n");
274 memset(&tmp[k], 0, sizeof(tmp[k]) * GROWTH_FACTOR);
276 kp->size += GROWTH_FACTOR;
278 kp->pages[kp->len].hash = hash;
279 kp->pages[kp->len].pattern =
280 is_pattern((uint8_t *)data, pm_kernel_pagesize(ker)) ?
281 (data[0] & 0xFF) : NO_PATTERN;
285 cur_page = &kp->pages[k];
287 if (pr_flags & PR_VERBOSE) {
288 if (cur_page->vaddr_len > 0 &&
289 cur_page->vaddr[cur_page->vaddr_len - 1].pid == pid &&
290 cur_page->vaddr[cur_page->vaddr_len - 1].addr ==
291 vaddr - (cur_page->vaddr[cur_page->vaddr_len - 1].num_pages *
292 pm_kernel_pagesize(ker))) {
293 cur_page->vaddr[cur_page->vaddr_len - 1].num_pages++;
295 if (cur_page->vaddr_len == cur_page->vaddr_size) {
296 struct vaddr *tmp = realloc(cur_page->vaddr,
297 (cur_page->vaddr_size + GROWTH_FACTOR) * sizeof(*(cur_page->vaddr)));
299 fprintf(stderr, "warning: not enough memory to realloc vaddr array\n");
304 memset(&tmp[cur_page->vaddr_len], 0, sizeof(tmp[cur_page->vaddr_len]) * GROWTH_FACTOR);
305 cur_page->vaddr = tmp;
306 cur_page->vaddr_size += GROWTH_FACTOR;
308 cur_page->vaddr[cur_page->vaddr_len].addr = vaddr;
309 cur_page->vaddr[cur_page->vaddr_len].num_pages = 1;
310 cur_page->vaddr[cur_page->vaddr_len].pid = pid;
311 cur_page->vaddr_len++;
314 cur_page->vaddr_count++;
321 if (pr_flags & PR_VERBOSE) {
322 for (i = 0; i < kp->len; i++) {
323 free(kp->pages[i].vaddr);
335 static void print_pages(struct ksm_pages *kp, uint8_t pr_flags) {
340 for (i = 0; i < kp->len; i++) {
341 if (kp->pages[i].pattern != NO_PATTERN) {
342 printf("0x%02x byte pattern: ", kp->pages[i].pattern);
344 printf("KSM CRC 0x%08x:", kp->pages[i].hash);
346 printf(" %4d page", kp->pages[i].vaddr_count);
347 if (kp->pages[i].vaddr_count > 1) {
352 if (pr_flags & PR_VERBOSE) {
354 while (j < kp->pages[i].vaddr_len) {
356 for (k = 0; k < 8 && j < kp->pages[i].vaddr_len; k++, j++) {
357 printf(" 0x%08lx", kp->pages[i].vaddr[j].addr);
359 index = snprintf(suffix, sizeof(suffix), ":%d",
360 kp->pages[i].vaddr[j].num_pages);
361 if (pr_flags & PR_ALL) {
362 index += snprintf(suffix + index, sizeof(suffix) - index, "[%d]",
363 kp->pages[i].vaddr[j].pid);
365 printf("%-12s", suffix);
373 static void free_pages(struct ksm_pages *kp, uint8_t pr_flags) {
376 if (pr_flags & PR_VERBOSE) {
377 for (i = 0; i < kp->len; i++) {
378 free(kp->pages[i].vaddr);
384 static void usage(char *myname) {
385 fprintf(stderr, "Usage: %s [-s | -v | -a | -h ] <pid>\n"
386 " -s Sort pages by usage count.\n"
387 " -v Verbose: print virtual addresses.\n"
388 " -a Display all the KSM pages in the system. Ignore the pid argument.\n"
389 " -h Display this help screen.\n",
393 static int cmp_pages(const void *a, const void *b) {
394 const struct ksm_page *pg_a = a;
395 const struct ksm_page *pg_b = b;
397 return pg_b->vaddr_count - pg_a->vaddr_count;
400 static bool is_pattern(uint8_t *data, size_t len) {
402 uint8_t first_byte = data[0];
404 for (i = 1; i < len; i++) {
405 if (first_byte != data[i]) return false;
412 * Get the process name for a given PID. Inserts the process name into buffer
413 * buf of length len. The size of the buffer must be greater than zero to get
416 * Note that fgets(3) only declares length as an int, so our buffer size is
417 * also declared as an int.
419 * Returns 0 on success, a positive value on partial success, and -1 on
420 * failure. Other interesting values:
421 * 1 on failure to create string to examine proc cmdline entry
422 * 2 on failure to open proc cmdline entry
423 * 3 on failure to read proc cmdline entry
425 static int getprocname(pid_t pid, char *buf, int len) {
429 static const char* unknown_cmdline = "<unknown>";
435 if (asprintf(&filename, "/proc/%zd/cmdline", pid) < 0) {
440 f = fopen(filename, "r");
443 goto releasefilename;
446 if (fgets(buf, len, f) == NULL) {
458 * The process went away before we could read its process name. Try
459 * to give the user "<unknown>" here, but otherwise they get to look
462 if (strlcpy(buf, unknown_cmdline, (size_t)len) >= (size_t)len) {