libstore/globals.cc: Move cgroup detection to libutil

This commit is contained in:
Alex Wied 2022-07-19 02:09:46 -04:00
parent 1af5d798a4
commit 722de8ddcc
3 changed files with 60 additions and 48 deletions

View file

@ -11,11 +11,6 @@
#include <dlfcn.h> #include <dlfcn.h>
#include <sys/utsname.h> #include <sys/utsname.h>
#if __linux__
#include <mntent.h>
#include <cmath>
#endif
#include <nlohmann/json.hpp> #include <nlohmann/json.hpp>
@ -119,49 +114,12 @@ std::vector<Path> getUserConfigFiles()
unsigned int Settings::getDefaultCores() unsigned int Settings::getDefaultCores()
{ {
unsigned int concurrency = std::max(1U, std::thread::hardware_concurrency()); const unsigned int concurrency = std::max(1U, std::thread::hardware_concurrency());
const unsigned int maxCPU = getMaxCPU();
#if __linux__
FILE *fp = fopen("/proc/mounts", "r");
if (!fp)
return concurrency;
Strings cgPathParts;
struct mntent *ent;
while ((ent = getmntent(fp))) {
std::string mountType, mountPath;
mountType = ent->mnt_type;
mountPath = ent->mnt_dir;
if (mountType == "cgroup2") {
cgPathParts.push_back(mountPath);
break;
}
}
fclose(fp);
if (cgPathParts.size() > 0 && pathExists("/proc/self/cgroup")) {
std::string currentCgroup = readFile("/proc/self/cgroup");
Strings cgValues = tokenizeString<Strings>(currentCgroup, ":");
cgPathParts.push_back(trim(cgValues.back(), "\n"));
cgPathParts.push_back("cpu.max");
std::string fullCgPath = canonPath(concatStringsSep("/", cgPathParts));
if (pathExists(fullCgPath)) {
std::string cpuMax = readFile(fullCgPath);
std::vector<std::string> cpuMaxParts = tokenizeString<std::vector<std::string>>(cpuMax, " ");
std::string quota = cpuMaxParts[0];
std::string period = trim(cpuMaxParts[1], "\n");
if (quota != "max")
concurrency = std::ceil(std::stoi(quota) / std::stof(period));
}
}
#endif
if (maxCPU > 0)
return maxCPU;
else
return concurrency; return concurrency;
} }

View file

@ -35,6 +35,9 @@
#ifdef __linux__ #ifdef __linux__
#include <sys/prctl.h> #include <sys/prctl.h>
#include <sys/resource.h> #include <sys/resource.h>
#include <mntent.h>
#include <cmath>
#endif #endif
@ -788,7 +791,55 @@ void drainFD(int fd, Sink & sink, bool block)
} }
} }
//////////////////////////////////////////////////////////////////////
unsigned int getMaxCPU()
{
#if __linux__
try {
FILE *fp = fopen("/proc/mounts", "r");
if (!fp)
return 0;
Strings cgPathParts;
struct mntent *ent;
while ((ent = getmntent(fp))) {
std::string mountType, mountPath;
mountType = ent->mnt_type;
mountPath = ent->mnt_dir;
if (mountType == "cgroup2") {
cgPathParts.push_back(mountPath);
break;
}
}
fclose(fp);
if (cgPathParts.size() > 0 && pathExists("/proc/self/cgroup")) {
std::string currentCgroup = readFile("/proc/self/cgroup");
Strings cgValues = tokenizeString<Strings>(currentCgroup, ":");
cgPathParts.push_back(trim(cgValues.back(), "\n"));
cgPathParts.push_back("cpu.max");
std::string fullCgPath = canonPath(concatStringsSep("/", cgPathParts));
if (pathExists(fullCgPath)) {
std::string cpuMax = readFile(fullCgPath);
std::vector<std::string> cpuMaxParts = tokenizeString<std::vector<std::string>>(cpuMax, " ");
std::string quota = cpuMaxParts[0];
std::string period = trim(cpuMaxParts[1], "\n");
if (quota != "max")
return std::ceil(std::stoi(quota) / std::stof(period));
}
}
} catch (Error &) { ignoreException(); }
#endif
return 0;
}
////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////

View file

@ -182,6 +182,9 @@ std::string drainFD(int fd, bool block = true, const size_t reserveSize=0);
void drainFD(int fd, Sink & sink, bool block = true); void drainFD(int fd, Sink & sink, bool block = true);
/* If cgroups are active, attempt to calculate the number of CPUs available.
If cgroups are unavailable or if cpu.max is set to "max", return 0. */
unsigned int getMaxCPU();
/* Automatic cleanup of resources. */ /* Automatic cleanup of resources. */