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) {
200 char filename[MAX_FILENAME];
204 struct ksm_page *cur_page;
210 pid = pm_process_pid(maps[0]->proc);
211 ker = maps[0]->proc->ker;
212 error = snprintf(filename, MAX_FILENAME, "/proc/%d/mem", pid);
213 if (error < 0 || error >= MAX_FILENAME) {
217 data = malloc(pm_kernel_pagesize(ker));
219 fprintf(stderr, "warning: not enough memory to malloc data buffer\n");
223 fd = open(filename, O_RDONLY);
225 fprintf(stderr, "warning: could not open %s\n", filename);
230 for (i = 0; i < num_maps; i++) {
231 error = pm_map_pagemap(maps[i], &pagemap, &map_len);
233 fprintf(stderr, "warning: could not read the pagemap of %d\n",
234 pm_process_pid(maps[i]->proc));
237 for (j = 0; j < map_len; j++) {
238 error = pm_kernel_flags(ker, PM_PAGEMAP_PFN(pagemap[j]), &flags);
240 fprintf(stderr, "warning: could not read flags for pfn at address 0x%016" PRIx64 "\n",
244 if (!(flags & KPF_KSM)) {
247 vaddr = pm_map_start(maps[i]) + j * pm_kernel_pagesize(ker);
248 off = lseek(fd, vaddr, SEEK_SET);
249 if (off == (off_t)-1) {
250 fprintf(stderr, "warning: could not lseek to 0x%08lx\n", vaddr);
253 ssize_t len = read(fd, data, pm_kernel_pagesize(ker));
254 if (len != pm_kernel_pagesize(ker)) {
255 fprintf(stderr, "warning: could not read page at 0x%08lx\n", vaddr);
259 hash = hashword(data, pm_kernel_pagesize(ker) / sizeof(*data), 17);
261 for (k = 0; k < kp->len; k++) {
262 if (kp->pages[k].hash == hash) break;
266 if (kp->len == kp->size) {
267 struct ksm_page *tmp = realloc(kp->pages,
268 (kp->size + GROWTH_FACTOR) * sizeof(*kp->pages));
270 fprintf(stderr, "warning: not enough memory to realloc pages struct\n");
275 memset(&tmp[k], 0, sizeof(tmp[k]) * GROWTH_FACTOR);
277 kp->size += GROWTH_FACTOR;
279 rc = pm_kernel_count(ker, PM_PAGEMAP_PFN(pagemap[j]), &kp->pages[kp->len].count);
281 fprintf(stderr, "error reading page count\n");
285 kp->pages[kp->len].hash = hash;
286 kp->pages[kp->len].pattern =
287 is_pattern((uint8_t *)data, pm_kernel_pagesize(ker)) ?
288 (data[0] & 0xFF) : NO_PATTERN;
292 cur_page = &kp->pages[k];
294 if (pr_flags & PR_VERBOSE) {
295 if (cur_page->vaddr_len > 0 &&
296 cur_page->vaddr[cur_page->vaddr_len - 1].pid == pid &&
297 cur_page->vaddr[cur_page->vaddr_len - 1].addr ==
298 vaddr - (cur_page->vaddr[cur_page->vaddr_len - 1].num_pages *
299 pm_kernel_pagesize(ker))) {
300 cur_page->vaddr[cur_page->vaddr_len - 1].num_pages++;
302 if (cur_page->vaddr_len == cur_page->vaddr_size) {
303 struct vaddr *tmp = realloc(cur_page->vaddr,
304 (cur_page->vaddr_size + GROWTH_FACTOR) * sizeof(*(cur_page->vaddr)));
306 fprintf(stderr, "warning: not enough memory to realloc vaddr array\n");
311 memset(&tmp[cur_page->vaddr_len], 0, sizeof(tmp[cur_page->vaddr_len]) * GROWTH_FACTOR);
312 cur_page->vaddr = tmp;
313 cur_page->vaddr_size += GROWTH_FACTOR;
315 cur_page->vaddr[cur_page->vaddr_len].addr = vaddr;
316 cur_page->vaddr[cur_page->vaddr_len].num_pages = 1;
317 cur_page->vaddr[cur_page->vaddr_len].pid = pid;
318 cur_page->vaddr_len++;
321 cur_page->vaddr_count++;
329 if (pr_flags & PR_VERBOSE) {
330 for (i = 0; i < kp->len; i++) {
331 free(kp->pages[i].vaddr);
343 static void print_pages(struct ksm_pages *kp, uint8_t pr_flags) {
348 for (i = 0; i < kp->len; i++) {
349 if (kp->pages[i].pattern != NO_PATTERN) {
350 printf("0x%02x byte pattern: ", kp->pages[i].pattern);
352 printf("KSM CRC 0x%08x:", kp->pages[i].hash);
354 printf(" %4zu page", kp->pages[i].vaddr_count);
355 if (kp->pages[i].vaddr_count > 1) {
358 if (!(pr_flags & PR_ALL)) {
359 printf(" (%" PRIu64 " reference", kp->pages[i].count);
360 if (kp->pages[i].count > 1) {
367 if (pr_flags & PR_VERBOSE) {
369 while (j < kp->pages[i].vaddr_len) {
371 for (k = 0; k < 8 && j < kp->pages[i].vaddr_len; k++, j++) {
372 printf(" 0x%08lx", kp->pages[i].vaddr[j].addr);
374 index = snprintf(suffix, sizeof(suffix), ":%zu",
375 kp->pages[i].vaddr[j].num_pages);
376 if (pr_flags & PR_ALL) {
377 index += snprintf(suffix + index, sizeof(suffix) - index, "[%d]",
378 kp->pages[i].vaddr[j].pid);
380 printf("%-12s", suffix);
388 static void free_pages(struct ksm_pages *kp, uint8_t pr_flags) {
391 if (pr_flags & PR_VERBOSE) {
392 for (i = 0; i < kp->len; i++) {
393 free(kp->pages[i].vaddr);
399 static void usage(char *myname) {
400 fprintf(stderr, "Usage: %s [-s | -v | -a | -h ] <pid>\n"
401 " -s Sort pages by usage count.\n"
402 " -v Verbose: print virtual addresses.\n"
403 " -a Display all the KSM pages in the system. Ignore the pid argument.\n"
404 " -h Display this help screen.\n",
408 static int cmp_pages(const void *a, const void *b) {
409 const struct ksm_page *pg_a = a;
410 const struct ksm_page *pg_b = b;
411 int cmp = pg_b->vaddr_count - pg_a->vaddr_count;
413 return cmp ? cmp : pg_b->count - pg_a->count;
416 static bool is_pattern(uint8_t *data, size_t len) {
418 uint8_t first_byte = data[0];
420 for (i = 1; i < len; i++) {
421 if (first_byte != data[i]) return false;
428 * Get the process name for a given PID. Inserts the process name into buffer
429 * buf of length len. The size of the buffer must be greater than zero to get
432 * Note that fgets(3) only declares length as an int, so our buffer size is
433 * also declared as an int.
435 * Returns 0 on success, a positive value on partial success, and -1 on
436 * failure. Other interesting values:
437 * 1 on failure to create string to examine proc cmdline entry
438 * 2 on failure to open proc cmdline entry
439 * 3 on failure to read proc cmdline entry
441 static int getprocname(pid_t pid, char *buf, int len) {
445 static const char* unknown_cmdline = "<unknown>";
451 if (asprintf(&filename, "/proc/%d/cmdline", (int)pid) < 0) {
456 f = fopen(filename, "r");
459 goto releasefilename;
462 if (fgets(buf, len, f) == NULL) {
474 * The process went away before we could read its process name. Try
475 * to give the user "<unknown>" here, but otherwise they get to look
478 if (strlcpy(buf, unknown_cmdline, (size_t)len) >= (size_t)len) {