tools/mm: fix the default case for page_owner_sort

With the additional commands and timestamps added to the tool, the default
case (-t) has been broken.  Now that the allocation timestamps are saved
outside of the txt field, allow us to properly sort the data by number of
times the record has been seen.  Furthermore prevent the misuse of the
commandline arguments so only one compare option can be used.

Link: https://lkml.kernel.org/r/20231013190350.579407-5-audra@redhat.comSigned-off-by: Audra Mitchell <audra@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/mm/page_owner_sort.c

@@ -66,6 +66,16 @@ enum SORT_ORDER {
 	SORT_ASC = 1,
 	SORT_DESC = -1,
 };
+enum COMP_FLAG {
+	COMP_NO_FLAG = 0,
+	COMP_ALLOC = 1<<0,
+	COMP_PAGE_NUM = 1<<1,
+	COMP_PID = 1<<2,
+	COMP_STACK = 1<<3,
+	COMP_NUM = 1<<4,
+	COMP_TGID = 1<<5,
+	COMP_COMM = 1<<6
+};
 struct filter_condition {
 	pid_t *pids;
 	pid_t *tgids;
@@ -644,7 +654,7 @@ int main(int argc, char **argv)
 {
 	FILE *fin, *fout;
 	char *buf, *ext_buf;
-	int i, count;
+	int i, count, compare_flag;
 	struct stat st;
 	int opt;
 	struct option longopts[] = {
@@ -656,31 +666,33 @@ int main(int argc, char **argv)
 		{ 0, 0, 0, 0},
 	};
 
+	compare_flag = COMP_NO_FLAG;
+
 	while ((opt = getopt_long(argc, argv, "admnpstP", longopts, NULL)) != -1)
 		switch (opt) {
 		case 'a':
-			set_single_cmp(compare_ts, SORT_ASC);
+			compare_flag |= COMP_ALLOC;
 			break;
 		case 'd':
 			debug_on = true;
 			break;
 		case 'm':
-			set_single_cmp(compare_page_num, SORT_DESC);
+			compare_flag |= COMP_PAGE_NUM;
 			break;
 		case 'p':
-			set_single_cmp(compare_pid, SORT_ASC);
+			compare_flag |= COMP_PID;
 			break;
 		case 's':
-			set_single_cmp(compare_stacktrace, SORT_ASC);
+			compare_flag |= COMP_STACK;
 			break;
 		case 't':
-			set_single_cmp(compare_num, SORT_DESC);
+			compare_flag |= COMP_NUM;
 			break;
 		case 'P':
-			set_single_cmp(compare_tgid, SORT_ASC);
+			compare_flag |= COMP_TGID;
 			break;
 		case 'n':
-			set_single_cmp(compare_comm, SORT_ASC);
+			compare_flag |= COMP_COMM;
 			break;
 		case 1:
 			filter = filter | FILTER_PID;
@@ -728,6 +740,39 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
+	/* Only one compare option is allowed, yet we also want handle the
+	 * default case were no option is provided, but we still want to
+	 * match the behavior of the -t option (compare by number of times
+	 * a record is seen
+	 */
+	switch (compare_flag) {
+	case COMP_ALLOC:
+		set_single_cmp(compare_ts, SORT_ASC);
+		break;
+	case COMP_PAGE_NUM:
+		set_single_cmp(compare_page_num, SORT_DESC);
+		break;
+	case COMP_PID:
+		set_single_cmp(compare_pid, SORT_ASC);
+		break;
+	case COMP_STACK:
+		set_single_cmp(compare_stacktrace, SORT_ASC);
+		break;
+	case COMP_NO_FLAG:
+	case COMP_NUM:
+		set_single_cmp(compare_num, SORT_DESC);
+		break;
+	case COMP_TGID:
+		set_single_cmp(compare_tgid, SORT_ASC);
+		break;
+	case COMP_COMM:
+		set_single_cmp(compare_comm, SORT_ASC);
+		break;
+	default:
+		usage();
+		exit(1);
+	}
+
 	fin = fopen(argv[optind], "r");
 	fout = fopen(argv[optind + 1], "w");
 	if (!fin || !fout) {