Commit cd75ea0e authored by Yinan Zhang's avatar Yinan Zhang Committed by Linus Torvalds
Browse files

tools/vm/page_owner_sort.c: add switch between culling by stacktrace and txt 

Culling by comparing stacktrace would casue loss of some information.  For
example, if there exists 2 blocks which have the same stacktrace and the
different head info

  Page allocated via order 0, mask 0x108c48(...), pid 73696,
    ts 1578829190639010 ns, free_ts 1576583851324450 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

  Page allocated via order 0, mask 0x108c48(...), pid 61806,
    ts 1354113726046100 ns, free_ts 1354104926841400 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

After culling, it would be like this

  2 times, 2 pages:
  Page allocated via order 0, mask 0x108c48(...), pid 73696,
    ts 1578829190639010 ns, free_ts 1576583851324450 ns
    prep_new_page+0x80/0xb8
    get_page_from_freelist+0x924/0xee8
    __alloc_pages+0x138/0xc18
    alloc_pages+0x80/0xf0
    __page_cache_alloc+0x90/0xc8

The info of second block missed.  So, add -c to turn on culling by
stacktrace.  By default, it will cull by txt.

Link: https://lkml.kernel.org/r/20211129145658.2491-1-zhangyinan2019@email.szu.edu.cn


Signed-off-by: default avatarYinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Changhee Han <ch0.han@lge.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Tang Bin <tangbin@cmss.chinamobile.com>
Cc: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 82f5ebc2

tools/vm/page_owner_sort.c

+20 −3
Original line number Diff line number Diff line
@@ -51,6 +51,13 @@ int read_block(char *buf, int buf_size, FILE *fin) 
	return -1; /* EOF or no space left in buf. */

}



static int compare_txt(const void *p1, const void *p2)

{

	const struct block_list *l1 = p1, *l2 = p2;



	return strcmp(l1->txt, l2->txt);

}



static int compare_stacktrace(const void *p1, const void *p2)

{

	const struct block_list *l1 = p1, *l2 = p2;
@@ -137,12 +144,14 @@ static void usage(void) 
		"-m	Sort by total memory.\n"

		"-s	Sort by the stack trace.\n"

		"-t	Sort by times (default).\n"

		"-c	cull by comparing stacktrace instead of total block.\n"

	);

}



int main(int argc, char **argv)

{

	int (*cmp)(const void *, const void *) = compare_num;

	int cull_st = 0;

	FILE *fin, *fout;

	char *buf;

	int ret, i, count;
@@ -151,7 +160,7 @@ int main(int argc, char **argv) 
	int err;

	int opt;



	while ((opt = getopt(argc, argv, "mst")) != -1)

	while ((opt = getopt(argc, argv, "mstc")) != -1)

		switch (opt) {

		case 'm':

			cmp = compare_page_num;
@@ -162,6 +171,9 @@ int main(int argc, char **argv) 
		case 't':

			cmp = compare_num;

			break;

		case 'c':

			cull_st = 1;

			break;

		default:

			usage();

			exit(1);
@@ -209,7 +221,10 @@ int main(int argc, char **argv) 


	printf("sorting ....\n");



	if (cull_st == 1)

		qsort(list, list_size, sizeof(list[0]), compare_stacktrace);

	else

		qsort(list, list_size, sizeof(list[0]), compare_txt);



	list2 = malloc(sizeof(*list) * list_size);

	if (!list2) {
@@ -219,9 +234,11 @@ int main(int argc, char **argv) 


	printf("culling\n");



	long offset = cull_st ? &list[0].stacktrace - &list[0].txt : 0;



	for (i = count = 0; i < list_size; i++) {

		if (count == 0 ||

		    strcmp(list2[count-1].stacktrace, list[i].stacktrace) != 0) {

		    strcmp(*(&list2[count-1].txt+offset), *(&list[i].txt+offset)) != 0) {

			list2[count++] = list[i];

		} else {

			list2[count-1].num += list[i].num;