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.
25 #include <sys/types.h>
28 #include <pagemap/pagemap.h>
30 #define MAX_FILENAME 64
32 #define GROWTH_FACTOR 10
34 #define NO_PATTERN 0x100
50 size_t vaddr_len, vaddr_size;
56 struct ksm_page *pages;
60 static void usage(char *myname);
61 static int getprocname(pid_t pid, char *buf, int len);
62 static int read_pages(struct ksm_pages *kp, pm_map_t **maps, size_t num_maps, uint8_t pr_flags);
63 static void print_pages(struct ksm_pages *kp, uint8_t pr_flags);
64 static void free_pages(struct ksm_pages *kp, uint8_t pr_flags);
65 static bool is_pattern(uint8_t *data, size_t len);
66 static int cmp_pages(const void *a, const void *b);
67 extern uint32_t hashword(const uint32_t *, size_t, int32_t);
69 int main(int argc, char *argv[]) {
77 char cmdline[256]; // this must be within the range of int
79 int rc = EXIT_SUCCESS;
83 memset(&kp, 0, sizeof(kp));
87 int c = getopt(argc, argv, "hvsa");
96 pr_flags |= PR_SORTED;
99 pr_flags |= PR_VERBOSE;
105 fprintf(stderr, "unknown option: %c\n", optopt);
111 error = pm_kernel_create(&ker);
113 fprintf(stderr, "Error creating kernel interface -- "
114 "does this kernel have pagemap?\n");
118 if (pr_flags & PR_ALL) {
119 error = pm_kernel_pids(ker, &pids, &num_procs);
121 fprintf(stderr, "Error listing processes.\n");
125 if (optind != argc - 1) {
130 pids = malloc(sizeof(*pids));
132 fprintf(stderr, "Error allocating pid memory\n");
136 *pids = strtoul(argv[optind], NULL, 10);
138 fprintf(stderr, "Invalid PID\n");
143 if (getprocname(*pids, cmdline, sizeof(cmdline)) < 0) {
146 printf("%s (%u):\n", cmdline, *pids);
149 printf("Warning: this tool only compares the KSM CRCs of pages, there is a chance of "
152 for (i = 0; i < num_procs; i++) {
153 error = pm_process_create(ker, pids[i], &proc);
155 fprintf(stderr, "warning: could not create process interface for %d\n", pids[i]);
160 error = pm_process_maps(proc, &maps, &num_maps);
162 pm_process_destroy(proc);
163 fprintf(stderr, "warning: could not read process map for %d\n", pids[i]);
168 if (read_pages(&kp, maps, num_maps, pr_flags) < 0) {
170 pm_process_destroy(proc);
176 pm_process_destroy(proc);
179 if (pr_flags & PR_SORTED) {
180 qsort(kp.pages, kp.len, sizeof(*kp.pages), cmp_pages);
182 print_pages(&kp, pr_flags);
185 free_pages(&kp, pr_flags);
190 static int read_pages(struct ksm_pages *kp, pm_map_t **maps, size_t num_maps, uint8_t pr_flags) {
201 char filename[MAX_FILENAME];
205 struct ksm_page *cur_page;
211 pid = pm_process_pid(maps[0]->proc);
212 ker = maps[0]->proc->ker;
213 error = snprintf(filename, MAX_FILENAME, "/proc/%d/mem", pid);
214 if (error < 0 || error >= MAX_FILENAME) {
218 data = malloc(pm_kernel_pagesize(ker));
220 fprintf(stderr, "warning: not enough memory to malloc data buffer\n");
224 fd = open(filename, O_RDONLY);
226 fprintf(stderr, "warning: could not open %s\n", filename);
231 for (i = 0; i < num_maps; i++) {
232 error = pm_map_pagemap(maps[i], &pagemap, &map_len);
234 fprintf(stderr, "warning: could not read the pagemap of %d\n",
235 pm_process_pid(maps[i]->proc));
238 for (j = 0; j < map_len; j++) {
239 error = pm_kernel_flags(ker, PM_PAGEMAP_PFN(pagemap[j]), &flags);
241 fprintf(stderr, "warning: could not read flags for pfn at address 0x%016" PRIx64 "\n",
245 if (!(flags & PM_PAGE_KSM)) {
248 vaddr = pm_map_start(maps[i]) + j * pm_kernel_pagesize(ker);
249 off = lseek(fd, vaddr, SEEK_SET);
250 if (off == (off_t)-1) {
251 fprintf(stderr, "warning: could not lseek to 0x%08lx\n", vaddr);
254 len = read(fd, data, pm_kernel_pagesize(ker));
255 if (len != pm_kernel_pagesize(ker)) {
256 fprintf(stderr, "warning: could not read page at 0x%08lx\n", vaddr);
260 hash = hashword(data, pm_kernel_pagesize(ker) / sizeof(*data), 17);
262 for (k = 0; k < kp->len; k++) {
263 if (kp->pages[k].hash == hash) break;
267 if (kp->len == kp->size) {
268 struct ksm_page *tmp = realloc(kp->pages,
269 (kp->size + GROWTH_FACTOR) * sizeof(*kp->pages));
271 fprintf(stderr, "warning: not enough memory to realloc pages struct\n");
276 memset(&tmp[k], 0, sizeof(tmp[k]) * GROWTH_FACTOR);
278 kp->size += GROWTH_FACTOR;
280 rc = pm_kernel_count(ker, PM_PAGEMAP_PFN(pagemap[j]), &kp->pages[kp->len].count);
282 fprintf(stderr, "error reading page count\n");
286 kp->pages[kp->len].hash = hash;
287 kp->pages[kp->len].pattern =
288 is_pattern((uint8_t *)data, pm_kernel_pagesize(ker)) ?
289 (data[0] & 0xFF) : NO_PATTERN;
293 cur_page = &kp->pages[k];
295 if (pr_flags & PR_VERBOSE) {
296 if (cur_page->vaddr_len > 0 &&
297 cur_page->vaddr[cur_page->vaddr_len - 1].pid == pid &&
298 cur_page->vaddr[cur_page->vaddr_len - 1].addr ==
299 vaddr - (cur_page->vaddr[cur_page->vaddr_len - 1].num_pages *
300 pm_kernel_pagesize(ker))) {
301 cur_page->vaddr[cur_page->vaddr_len - 1].num_pages++;
303 if (cur_page->vaddr_len == cur_page->vaddr_size) {
304 struct vaddr *tmp = realloc(cur_page->vaddr,
305 (cur_page->vaddr_size + GROWTH_FACTOR) * sizeof(*(cur_page->vaddr)));
307 fprintf(stderr, "warning: not enough memory to realloc vaddr array\n");
312 memset(&tmp[cur_page->vaddr_len], 0, sizeof(tmp[cur_page->vaddr_len]) * GROWTH_FACTOR);
313 cur_page->vaddr = tmp;
314 cur_page->vaddr_size += GROWTH_FACTOR;
316 cur_page->vaddr[cur_page->vaddr_len].addr = vaddr;
317 cur_page->vaddr[cur_page->vaddr_len].num_pages = 1;
318 cur_page->vaddr[cur_page->vaddr_len].pid = pid;
319 cur_page->vaddr_len++;
322 cur_page->vaddr_count++;
330 if (pr_flags & PR_VERBOSE) {
331 for (i = 0; i < kp->len; i++) {
332 free(kp->pages[i].vaddr);
344 static void print_pages(struct ksm_pages *kp, uint8_t pr_flags) {
349 for (i = 0; i < kp->len; i++) {
350 if (kp->pages[i].pattern != NO_PATTERN) {
351 printf("0x%02x byte pattern: ", kp->pages[i].pattern);
353 printf("KSM CRC 0x%08x:", kp->pages[i].hash);
355 printf(" %4zu page", kp->pages[i].vaddr_count);
356 if (kp->pages[i].vaddr_count > 1) {
359 if (!(pr_flags & PR_ALL)) {
360 printf(" (%" PRIu64 " reference", kp->pages[i].count);
361 if (kp->pages[i].count > 1) {
368 if (pr_flags & PR_VERBOSE) {
370 while (j < kp->pages[i].vaddr_len) {
372 for (k = 0; k < 8 && j < kp->pages[i].vaddr_len; k++, j++) {
373 printf(" 0x%08lx", kp->pages[i].vaddr[j].addr);
375 index = snprintf(suffix, sizeof(suffix), ":%zu",
376 kp->pages[i].vaddr[j].num_pages);
377 if (pr_flags & PR_ALL) {
378 index += snprintf(suffix + index, sizeof(suffix) - index, "[%d]",
379 kp->pages[i].vaddr[j].pid);
381 printf("%-12s", suffix);
389 static void free_pages(struct ksm_pages *kp, uint8_t pr_flags) {
392 if (pr_flags & PR_VERBOSE) {
393 for (i = 0; i < kp->len; i++) {
394 free(kp->pages[i].vaddr);
400 static void usage(char *myname) {
401 fprintf(stderr, "Usage: %s [-s | -v | -a | -h ] <pid>\n"
402 " -s Sort pages by usage count.\n"
403 " -v Verbose: print virtual addresses.\n"
404 " -a Display all the KSM pages in the system. Ignore the pid argument.\n"
405 " -h Display this help screen.\n",
409 static int cmp_pages(const void *a, const void *b) {
410 const struct ksm_page *pg_a = a;
411 const struct ksm_page *pg_b = b;
412 int cmp = pg_b->vaddr_count - pg_a->vaddr_count;
414 return cmp ? cmp : pg_b->count - pg_a->count;
417 static bool is_pattern(uint8_t *data, size_t len) {
419 uint8_t first_byte = data[0];
421 for (i = 1; i < len; i++) {
422 if (first_byte != data[i]) return false;
429 * Get the process name for a given PID. Inserts the process name into buffer
430 * buf of length len. The size of the buffer must be greater than zero to get
433 * Note that fgets(3) only declares length as an int, so our buffer size is
434 * also declared as an int.
436 * Returns 0 on success, a positive value on partial success, and -1 on
437 * failure. Other interesting values:
438 * 1 on failure to create string to examine proc cmdline entry
439 * 2 on failure to open proc cmdline entry
440 * 3 on failure to read proc cmdline entry
442 static int getprocname(pid_t pid, char *buf, int len) {
446 static const char* unknown_cmdline = "<unknown>";
452 if (asprintf(&filename, "/proc/%d/cmdline", (int)pid) < 0) {
457 f = fopen(filename, "r");
460 goto releasefilename;
463 if (fgets(buf, len, f) == NULL) {
475 * The process went away before we could read its process name. Try
476 * to give the user "<unknown>" here, but otherwise they get to look
479 if (strlcpy(buf, unknown_cmdline, (size_t)len) >= (size_t)len) {