lix/src/libutil/affinity.cc
Eelco Dolstra 8f67325a7c Build sandbox support etc. unconditionally on Linux
Also, use "#if __APPLE__" instead of "#if SANDBOX_ENABLED" to prevent
ambiguity.
2015-12-10 11:47:17 +01:00

56 lines
1 KiB
C++

#include "types.hh"
#include "util.hh"
#include "affinity.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;
printMsg(lvlDebug, 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)
printMsg(lvlError, 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)
printMsg(lvlError, "failed to restore affinity %1%");
#endif
}
}