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
7 bool smt_on(void)
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(online_topology());
20
21 cached = true;
22 return cached_result;
23 }
24
25 bool core_wide(bool system_wide, const char *user_requested_cpu_list)
26 {
27 /* If not everything running on a core is being recorded then we can't use core_wide. */
28 if (!system_wide)
29 return false;
30
31 /* Cheap case that SMT is disabled and therefore we're inherently core_wide. */
32 if (!smt_on())
33 return true;
34
35 return cpu_topology__core_wide(online_topology(), user_requested_cpu_list);
36 }
37
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