1 // SPDX-License-Identifier: GPL-2.0-only !! 1 #include <stdio.h>
2 #include <string.h> !! 2 #include <stdlib.h>
>> 3 #include <unistd.h>
>> 4 #include <linux/bitops.h>
3 #include "api/fs/fs.h" 5 #include "api/fs/fs.h"
4 #include "cputopo.h" <<
5 #include "smt.h" 6 #include "smt.h"
6 7
7 bool smt_on(void) !! 8 int smt_on(void)
8 { 9 {
9 static bool cached; 10 static bool cached;
10 static bool cached_result; !! 11 static int cached_result;
11 int fs_value; !! 12 int cpu;
>> 13 int ncpu;
12 14
13 if (cached) 15 if (cached)
14 return cached_result; 16 return cached_result;
15 17
16 if (sysfs__read_int("devices/system/cp !! 18 if (sysfs__read_int("devices/system/cpu/smt/active", &cached_result) >= 0)
17 cached_result = (fs_value == 1 !! 19 goto done;
18 else <<
19 cached_result = cpu_topology__ <<
20 20
21 cached = true; !! 21 ncpu = sysconf(_SC_NPROCESSORS_CONF);
>> 22 for (cpu = 0; cpu < ncpu; cpu++) {
>> 23 unsigned long long siblings;
>> 24 char *str;
>> 25 size_t strlen;
>> 26 char fn[256];
>> 27
>> 28 snprintf(fn, sizeof fn,
>> 29 "devices/system/cpu/cpu%d/topology/core_cpus", cpu);
>> 30 if (sysfs__read_str(fn, &str, &strlen) < 0) {
>> 31 snprintf(fn, sizeof fn,
>> 32 "devices/system/cpu/cpu%d/topology/thread_siblings",
>> 33 cpu);
>> 34 if (sysfs__read_str(fn, &str, &strlen) < 0)
>> 35 continue;
>> 36 }
>> 37 /* Entry is hex, but does not have 0x, so need custom parser */
>> 38 siblings = strtoull(str, NULL, 16);
>> 39 free(str);
>> 40 if (hweight64(siblings) > 1) {
>> 41 cached_result = 1;
>> 42 cached = true;
>> 43 break;
>> 44 }
>> 45 }
>> 46 if (!cached) {
>> 47 cached_result = 0;
>> 48 done:
>> 49 cached = true;
>> 50 }
22 return cached_result; 51 return cached_result;
23 } <<
24 <<
25 bool core_wide(bool system_wide, const char *u <<
26 { <<
27 /* If not everything running on a core <<
28 if (!system_wide) <<
29 return false; <<
30 <<
31 /* Cheap case that SMT is disabled and <<
32 if (!smt_on()) <<
33 return true; <<
34 <<
35 return cpu_topology__core_wide(online_ <<
36 } 52 }
37 53
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