1// SPDX-License-Identifier: GPL-2.0-only
 2#include <string.h>
 3#include "api/fs/fs.h"
 4#include "cputopo.h"
 5#include "smt.h"
 6
 7bool smt_on(const struct cpu_topology *topology)
 8{
 9	static bool cached;
10	static bool cached_result;
11	int fs_value;
12
13	if (cached)
14		return cached_result;
15
16	if (sysfs__read_int("devices/system/cpu/smt/active", &fs_value) >= 0)
17		cached_result = (fs_value == 1);
18	else
19		cached_result = cpu_topology__smt_on(topology);
20
21	cached = true;
22	return cached_result;
23}
24
25bool core_wide(bool system_wide, const char *user_requested_cpu_list,
26	       const struct cpu_topology *topology)
27{
28	/* If not everything running on a core is being recorded then we can't use core_wide. */
29	if (!system_wide)
30		return false;
31
32	/* Cheap case that SMT is disabled and therefore we're inherently core_wide. */
33	if (!smt_on(topology))
34		return true;
35
36	return cpu_topology__core_wide(topology, user_requested_cpu_list);
37}