blob: faee4926d57940b823f5bdbbeca95766aba5d2d1 (
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
|
#include "affinity.hh"
#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;
debug(format("locking this thread to CPU %1%") % cpu);
cpu_set_t newAffinity;
CPU_ZERO(&newAffinity);
CPU_SET(cpu, &newAffinity);
if (sched_setaffinity(0, sizeof(cpu_set_t), &newAffinity) == -1)
printError(format("failed to lock thread to CPU %1%") % 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)
printError("failed to restore affinity %1%");
#endif
}
} // namespace nix
|
