From: Yinan Zhang <zhangyinan2019@xxxxxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxxx Signed-off-by: Yinan Zhang <zhangyinan2019@xxxxxxxxxxxxxxxx> Cc: Changhee Han <ch0.han@xxxxxxx> Cc: Sean Anderson <seanga2@xxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx> Cc: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx> Cc: Zhenliang Wei <weizhenliang@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/vm/page_owner_sort.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) --- a/tools/vm/page_owner_sort.c~tools-vm-page_owner_sortc-add-switch-between-culling-by-stacktrace-and-txt +++ a/tools/vm/page_owner_sort.c @@ -51,6 +51,13 @@ int read_block(char *buf, int buf_size, 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"); - qsort(list, list_size, sizeof(list[0]), compare_stacktrace); + 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; _
