blob: 7db8906eb0b4234ffa38f791620494c04a8db5d6 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
#include "affinity.hh"
#include <glog/logging.h>
#include "types.hh"
#include "util.hh"
#if __linux__
#include <sched.h>
#endif
namespace nix {
#if __linux__
static bool didSaveAffinity = false;
static cpu_set_t savedAffinity;
#endif
void setAffinityTo(int cpu) {
#if __linux__
if (sched_getaffinity(0, sizeof(cpu_set_t), &savedAffinity) == -1) {
return;
}
didSaveAffinity = true;
DLOG(INFO) << "locking this thread to CPU " << cpu;
cpu_set_t newAffinity;
CPU_ZERO(&newAffinity);
CPU_SET(cpu, &newAffinity);
if (sched_setaffinity(0, sizeof(cpu_set_t), &newAffinity) == -1) {
LOG(ERROR) << "failed to lock thread to CPU " << cpu;
}
#endif
}
int lockToCurrentCPU() {
#if __linux__
int cpu = sched_getcpu();
if (cpu != -1) {
setAffinityTo(cpu);
}
return cpu;
#else
return -1;
#endif
}
void restoreAffinity() {
#if __linux__
if (!didSaveAffinity) {
return;
}
if (sched_setaffinity(0, sizeof(cpu_set_t), &savedAffinity) == -1) {
LOG(ERROR) << "failed to restore affinity";
}
#endif
}
} // namespace nix
|
