guix/nix/libutil/affinity.cc
Congcong Kuo 85a72ed28e
daemon: Use starts_with() and ends_with() instead of string() or hasSuffix()
* nix/libstore/build.cc (DerivationGoal::tryBuildHook): Use starts_with instead
of string()
* nix/libstore/builtins.cc (lookupBuiltinBuilder): Same.
* nix/libstore/builtins.hh (isBuiltin): Same and fix indentation of the file.
* nix/libstore/derivations.cc (DerivationOutput::parseHashInfo, isDerivation):
Same and clean header files.
* nix/libstore/gc.cc (addPermRoot, LocalStore::isActiveTempFile): Same.
* nix/libstore/globals.cc: Same.
* nix/libstore/local-store.cc: Same.
* nix/libstore/misc.cc: Same.
* nix/libstore/store-api.cc (checkStoreName): Same.
* nix/libutil/affinity.cc: Same.
* nix/libutil/archive.cc: Same.
* nix/libutil/spawn.cc: Same.
* nix/libutil/util.{cc, hh} (hasSuffix): Removed.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>
2025-11-03 17:18:37 +01:00

57 lines
1.1 KiB
C++

#include "types.hh"
#include "util.hh"
#include "affinity.hh"
#include <format>
#if HAVE_SCHED_H
#include <sched.h>
#endif
namespace nix {
#if HAVE_SCHED_SETAFFINITY
static bool didSaveAffinity = false;
static cpu_set_t savedAffinity;
#endif
void setAffinityTo(int cpu)
{
#if HAVE_SCHED_SETAFFINITY
if (sched_getaffinity(0, sizeof(cpu_set_t), &savedAffinity) == -1) return;
didSaveAffinity = true;
printMsg(lvlDebug, std::format("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)
printMsg(lvlError, std::format("failed to lock thread to CPU {}", cpu));
#endif
}
int lockToCurrentCPU()
{
#if HAVE_SCHED_SETAFFINITY
int cpu = sched_getcpu();
if (cpu != -1) setAffinityTo(cpu);
return cpu;
#else
return -1;
#endif
}
void restoreAffinity()
{
#if HAVE_SCHED_SETAFFINITY
if (!didSaveAffinity) return;
if (sched_setaffinity(0, sizeof(cpu_set_t), &savedAffinity) == -1)
printMsg(lvlError, "failed to restore affinity %1%");
#endif
}
}