![Daniël de Kok](/assets/img/avatar_default.png)
When performing distributed builds of machine learning packages, it would be nice if builders without the required SIMD instructions can be excluded as build nodes. Since x86_64 has accumulated a large number of different instruction set extensions, listing all possible extensions would be unwieldy. AMD, Intel, Red Hat, and SUSE have recently defined four different microarchitecture levels that are now part of the x86-64 psABI supplement and will be used in glibc 2.33: https://gitlab.com/x86-psABIs/x86-64-ABI https://lwn.net/Articles/844831/ This change uses libcpuid to detect CPU features and then uses them to add the supported x86_64 levels to the additional system types. For example on a Ryzen 3700X: $ ~/aps/bin/nix -vv --version | grep "Additional system" Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux
276 lines
8.8 KiB
C++
276 lines
8.8 KiB
C++
#include "globals.hh"
|
||
#include "util.hh"
|
||
#include "archive.hh"
|
||
#include "args.hh"
|
||
#include "abstract-setting-to-json.hh"
|
||
#include "compute-levels.hh"
|
||
|
||
#include <algorithm>
|
||
#include <map>
|
||
#include <thread>
|
||
#include <dlfcn.h>
|
||
#include <sys/utsname.h>
|
||
|
||
#include <nlohmann/json.hpp>
|
||
|
||
|
||
namespace nix {
|
||
|
||
|
||
/* The default location of the daemon socket, relative to nixStateDir.
|
||
The socket is in a directory to allow you to control access to the
|
||
Nix daemon by setting the mode/ownership of the directory
|
||
appropriately. (This wouldn't work on the socket itself since it
|
||
must be deleted and recreated on startup.) */
|
||
#define DEFAULT_SOCKET_PATH "/daemon-socket/socket"
|
||
|
||
Settings settings;
|
||
|
||
static GlobalConfig::Register rSettings(&settings);
|
||
|
||
Settings::Settings()
|
||
: nixPrefix(NIX_PREFIX)
|
||
, nixStore(canonPath(getEnv("NIX_STORE_DIR").value_or(getEnv("NIX_STORE").value_or(NIX_STORE_DIR))))
|
||
, nixDataDir(canonPath(getEnv("NIX_DATA_DIR").value_or(NIX_DATA_DIR)))
|
||
, nixLogDir(canonPath(getEnv("NIX_LOG_DIR").value_or(NIX_LOG_DIR)))
|
||
, nixStateDir(canonPath(getEnv("NIX_STATE_DIR").value_or(NIX_STATE_DIR)))
|
||
, nixConfDir(canonPath(getEnv("NIX_CONF_DIR").value_or(NIX_CONF_DIR)))
|
||
, nixUserConfFiles(getUserConfigFiles())
|
||
, nixLibexecDir(canonPath(getEnv("NIX_LIBEXEC_DIR").value_or(NIX_LIBEXEC_DIR)))
|
||
, nixBinDir(canonPath(getEnv("NIX_BIN_DIR").value_or(NIX_BIN_DIR)))
|
||
, nixManDir(canonPath(NIX_MAN_DIR))
|
||
, nixDaemonSocketFile(canonPath(getEnv("NIX_DAEMON_SOCKET_PATH").value_or(nixStateDir + DEFAULT_SOCKET_PATH)))
|
||
{
|
||
buildUsersGroup = getuid() == 0 ? "nixbld" : "";
|
||
lockCPU = getEnv("NIX_AFFINITY_HACK") == "1";
|
||
allowSymlinkedStore = getEnv("NIX_IGNORE_SYMLINK_STORE") == "1";
|
||
|
||
caFile = getEnv("NIX_SSL_CERT_FILE").value_or(getEnv("SSL_CERT_FILE").value_or(""));
|
||
if (caFile == "") {
|
||
for (auto & fn : {"/etc/ssl/certs/ca-certificates.crt", "/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"})
|
||
if (pathExists(fn)) {
|
||
caFile = fn;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Backwards compatibility. */
|
||
auto s = getEnv("NIX_REMOTE_SYSTEMS");
|
||
if (s) {
|
||
Strings ss;
|
||
for (auto & p : tokenizeString<Strings>(*s, ":"))
|
||
ss.push_back("@" + p);
|
||
builders = concatStringsSep(" ", ss);
|
||
}
|
||
|
||
#if defined(__linux__) && defined(SANDBOX_SHELL)
|
||
sandboxPaths = tokenizeString<StringSet>("/bin/sh=" SANDBOX_SHELL);
|
||
#endif
|
||
|
||
|
||
/* chroot-like behavior from Apple's sandbox */
|
||
#if __APPLE__
|
||
sandboxPaths = tokenizeString<StringSet>("/System/Library/Frameworks /System/Library/PrivateFrameworks /bin/sh /bin/bash /private/tmp /private/var/tmp /usr/lib");
|
||
allowedImpureHostPrefixes = tokenizeString<StringSet>("/System/Library /usr/lib /dev /bin/sh");
|
||
#endif
|
||
}
|
||
|
||
void loadConfFile()
|
||
{
|
||
globalConfig.applyConfigFile(settings.nixConfDir + "/nix.conf");
|
||
|
||
/* We only want to send overrides to the daemon, i.e. stuff from
|
||
~/.nix/nix.conf or the command line. */
|
||
globalConfig.resetOverriden();
|
||
|
||
auto files = settings.nixUserConfFiles;
|
||
for (auto file = files.rbegin(); file != files.rend(); file++) {
|
||
globalConfig.applyConfigFile(*file);
|
||
}
|
||
|
||
auto nixConfEnv = getEnv("NIX_CONFIG");
|
||
if (nixConfEnv.has_value()) {
|
||
globalConfig.applyConfig(nixConfEnv.value(), "NIX_CONFIG");
|
||
}
|
||
|
||
}
|
||
|
||
std::vector<Path> getUserConfigFiles()
|
||
{
|
||
// Use the paths specified in NIX_USER_CONF_FILES if it has been defined
|
||
auto nixConfFiles = getEnv("NIX_USER_CONF_FILES");
|
||
if (nixConfFiles.has_value()) {
|
||
return tokenizeString<std::vector<string>>(nixConfFiles.value(), ":");
|
||
}
|
||
|
||
// Use the paths specified by the XDG spec
|
||
std::vector<Path> files;
|
||
auto dirs = getConfigDirs();
|
||
for (auto & dir : dirs) {
|
||
files.insert(files.end(), dir + "/nix/nix.conf");
|
||
}
|
||
return files;
|
||
}
|
||
|
||
unsigned int Settings::getDefaultCores()
|
||
{
|
||
return std::max(1U, std::thread::hardware_concurrency());
|
||
}
|
||
|
||
StringSet Settings::getDefaultSystemFeatures()
|
||
{
|
||
/* For backwards compatibility, accept some "features" that are
|
||
used in Nixpkgs to route builds to certain machines but don't
|
||
actually require anything special on the machines. */
|
||
StringSet features{"nixos-test", "benchmark", "big-parallel", "recursive-nix"};
|
||
|
||
#if __linux__
|
||
if (access("/dev/kvm", R_OK | W_OK) == 0)
|
||
features.insert("kvm");
|
||
#endif
|
||
|
||
return features;
|
||
}
|
||
|
||
StringSet Settings::getDefaultExtraPlatforms()
|
||
{
|
||
StringSet extraPlatforms;
|
||
|
||
if (std::string{SYSTEM} == "x86_64-linux" && !isWSL1())
|
||
extraPlatforms.insert("i686-linux");
|
||
|
||
#if __linux__
|
||
StringSet levels = computeLevels();
|
||
for (auto iter = levels.begin(); iter != levels.end(); ++iter)
|
||
extraPlatforms.insert(*iter + "-linux");
|
||
#elif __APPLE__
|
||
// Rosetta 2 emulation layer can run x86_64 binaries on aarch64
|
||
// machines. Note that we can’t force processes from executing
|
||
// x86_64 in aarch64 environments or vice versa since they can
|
||
// always exec with their own binary preferences.
|
||
if (pathExists("/Library/Apple/System/Library/LaunchDaemons/com.apple.oahd.plist")) {
|
||
if (std::string{SYSTEM} == "x86_64-darwin")
|
||
extraPlatforms.insert("aarch64-darwin");
|
||
else if (std::string{SYSTEM} == "aarch64-darwin")
|
||
extraPlatforms.insert("x86_64-darwin");
|
||
}
|
||
#endif
|
||
|
||
return extraPlatforms;
|
||
}
|
||
|
||
bool Settings::isExperimentalFeatureEnabled(const std::string & name)
|
||
{
|
||
auto & f = experimentalFeatures.get();
|
||
return std::find(f.begin(), f.end(), name) != f.end();
|
||
}
|
||
|
||
void Settings::requireExperimentalFeature(const std::string & name)
|
||
{
|
||
if (!isExperimentalFeatureEnabled(name))
|
||
throw Error("experimental Nix feature '%1%' is disabled; use '--experimental-features %1%' to override", name);
|
||
}
|
||
|
||
bool Settings::isWSL1()
|
||
{
|
||
struct utsname utsbuf;
|
||
uname(&utsbuf);
|
||
// WSL1 uses -Microsoft suffix
|
||
// WSL2 uses -microsoft-standard suffix
|
||
return hasSuffix(utsbuf.release, "-Microsoft");
|
||
}
|
||
|
||
const string nixVersion = PACKAGE_VERSION;
|
||
|
||
NLOHMANN_JSON_SERIALIZE_ENUM(SandboxMode, {
|
||
{SandboxMode::smEnabled, true},
|
||
{SandboxMode::smRelaxed, "relaxed"},
|
||
{SandboxMode::smDisabled, false},
|
||
});
|
||
|
||
template<> void BaseSetting<SandboxMode>::set(const std::string & str, bool append)
|
||
{
|
||
if (str == "true") value = smEnabled;
|
||
else if (str == "relaxed") value = smRelaxed;
|
||
else if (str == "false") value = smDisabled;
|
||
else throw UsageError("option '%s' has invalid value '%s'", name, str);
|
||
}
|
||
|
||
template<> bool BaseSetting<SandboxMode>::isAppendable()
|
||
{
|
||
return false;
|
||
}
|
||
|
||
template<> std::string BaseSetting<SandboxMode>::to_string() const
|
||
{
|
||
if (value == smEnabled) return "true";
|
||
else if (value == smRelaxed) return "relaxed";
|
||
else if (value == smDisabled) return "false";
|
||
else abort();
|
||
}
|
||
|
||
template<> void BaseSetting<SandboxMode>::convertToArg(Args & args, const std::string & category)
|
||
{
|
||
args.addFlag({
|
||
.longName = name,
|
||
.description = "Enable sandboxing.",
|
||
.category = category,
|
||
.handler = {[=]() { override(smEnabled); }}
|
||
});
|
||
args.addFlag({
|
||
.longName = "no-" + name,
|
||
.description = "Disable sandboxing.",
|
||
.category = category,
|
||
.handler = {[=]() { override(smDisabled); }}
|
||
});
|
||
args.addFlag({
|
||
.longName = "relaxed-" + name,
|
||
.description = "Enable sandboxing, but allow builds to disable it.",
|
||
.category = category,
|
||
.handler = {[=]() { override(smRelaxed); }}
|
||
});
|
||
}
|
||
|
||
void MaxBuildJobsSetting::set(const std::string & str, bool append)
|
||
{
|
||
if (str == "auto") value = std::max(1U, std::thread::hardware_concurrency());
|
||
else {
|
||
if (auto n = string2Int<decltype(value)>(str))
|
||
value = *n;
|
||
else
|
||
throw UsageError("configuration setting '%s' should be 'auto' or an integer", name);
|
||
}
|
||
}
|
||
|
||
|
||
void initPlugins()
|
||
{
|
||
for (const auto & pluginFile : settings.pluginFiles.get()) {
|
||
Paths pluginFiles;
|
||
try {
|
||
auto ents = readDirectory(pluginFile);
|
||
for (const auto & ent : ents)
|
||
pluginFiles.emplace_back(pluginFile + "/" + ent.name);
|
||
} catch (SysError & e) {
|
||
if (e.errNo != ENOTDIR)
|
||
throw;
|
||
pluginFiles.emplace_back(pluginFile);
|
||
}
|
||
for (const auto & file : pluginFiles) {
|
||
/* handle is purposefully leaked as there may be state in the
|
||
DSO needed by the action of the plugin. */
|
||
void *handle =
|
||
dlopen(file.c_str(), RTLD_LAZY | RTLD_LOCAL);
|
||
if (!handle)
|
||
throw Error("could not dynamically open plugin file '%s': %s", file, dlerror());
|
||
}
|
||
}
|
||
|
||
/* Since plugins can add settings, try to re-apply previously
|
||
unknown settings. */
|
||
globalConfig.reapplyUnknownSettings();
|
||
globalConfig.warnUnknownSettings();
|
||
}
|
||
|
||
}
|