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mirror of https://github.com/boostorg/build.git synced 2026-02-14 12:42:11 +00:00

Rework sysinfo cpu to avoid overcounts.

When running in Linux containers the POSIX sysconf can return "too many"
cores or cpus. Instead we prefer using Linux specific sched_getaffinity
there.
This commit is contained in:
Rene Rivera
2019-06-11 21:26:25 -05:00
parent 1309749518
commit c27d575fb3
2 changed files with 101 additions and 39 deletions

View File

@@ -272,6 +272,7 @@ int main( int argc, char * * argv, char * * arg_environ )
char const * progname = argv[ 0 ];
module_t * environ_module;
int is_debugger;
b2::system_info sys_info;
saved_argv0 = argv[ 0 ];
@@ -362,23 +363,23 @@ int main( int argc, char * * argv, char * * arg_environ )
usage( progname );
}
/* Set default parallel jobs to match cpu threads. This can be overridden
the usual way with -jX or PARALLELISM env var. */
globs.jobs = sys_info.cpu_thread_count();
/* Version info. */
if ( ( s = getoptval( optv, 'v', 0 ) ) )
{
out_printf( "B2 Version %s. %s.\n", VERSION, OSMINOR );
out_printf( " Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc.\n" );
out_printf( " Copyright 2001 David Turner.\n" );
out_printf( " Copyright 2001-2004 David Abrahams.\n" );
out_printf( " Copyright 2002-2019 Rene Rivera.\n" );
out_printf( " Copyright 2003-2015 Vladimir Prus.\n" );
out_printf( " Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc.\n" );
out_printf( " Copyright 2001 David Turner.\n" );
out_printf( " Copyright 2001-2004 David Abrahams.\n" );
out_printf( " Copyright 2002-2019 Rene Rivera.\n" );
out_printf( " Copyright 2003-2015 Vladimir Prus.\n" );
out_printf( "\n DEFAULTS: jobs = %i\n", globs.jobs);
return EXITOK;
}
/* Set default parallel jobs to match cpu threads. This can be overridden
the usual way with -jX or PARALLELISM env var. */
b2::system_info sys_info;
globs.jobs = sys_info.cpu_thread_count();
/* Pick up interesting options. */
if ( ( s = getoptval( optv, 'n', 0 ) ) )
{

View File

@@ -7,41 +7,103 @@
#include "jam.h"
#include "output.h"
#include <thread>
#if defined(OS_MACOSX)
#include <sys/types.h>
#include <sys/sysctl.h>
#endif
#if !defined(OS_NT)
#include <unistd.h>
#endif
#include <thread>
#if defined(OS_LINUX)
#define _GNU_SOURCE
#include <sched.h>
#undef _GNU_SOURCE
#endif
b2::system_info::system_info()
{
}
unsigned int b2::system_info::cpu_core_count()
namespace
{
if (cpu_core_count_ == 0)
unsigned int macosx_physicalcpu()
{
#if defined(OS_MACOSX)
int out_hw_ncpu = 0;
size_t len_hw_ncpu = sizeof(out_hw_ncpu);
int result = ::sysctlbyname(
"hw.physicalcpu", &out_hw_ncpu, &len_hw_ncpu, nullptr, 0);
if (result == 0)
{
cpu_core_count_ = out_hw_ncpu;
}
#elif defined(_SC_NPROCESSORS_CONF)
cpu_thread_count_ = ::sysconf(_SC_NPROCESSORS_CONF);
if (result == 0) return out_hw_ncpu;
#endif
if (cpu_core_count_ <= 0)
return 0;
}
unsigned int macosx_logicalcpu()
{
#if defined(OS_MACOSX)
int out_hw_ncpu = 0;
size_t len_hw_ncpu = sizeof(out_hw_ncpu);
int result = ::sysctlbyname(
"hw.logicalcpu", &out_hw_ncpu, &len_hw_ncpu, nullptr, 0);
if (result == 0) return out_hw_ncpu;
#endif
return 0;
}
unsigned int sched_affinity_cpu_count()
{
#if defined(CPU_COUNT_S)
::cpu_set_t cpu_set;
if (::sched_getaffinity(0, sizeof(cpu_set_t), &cpu_set) == 0)
{
cpu_core_count_ = 1;
return CPU_COUNT_S(sizeof(cpu_set_t), &cpu_set);
}
#endif
return 0;
}
unsigned int sysconf_nprocs_configured()
{
#if defined(_SC_NPROCESSORS_ONLN)
return ::sysconf(_SC_NPROCESSORS_CONF);
#else
return 0;
#endif
}
unsigned int sysconf_nprocs_online()
{
#if defined(_SC_NPROCESSORS_ONLN)
return ::sysconf(_SC_NPROCESSORS_ONLN);
#else
return 0;
#endif
}
unsigned int std_thread_hardware_concurrency()
{
return std::thread::hardware_concurrency();
}
}
unsigned int b2::system_info::cpu_core_count()
{
if (cpu_core_count_ == 0)
{
cpu_thread_count_ = macosx_physicalcpu();
}
if (cpu_thread_count_ == 0)
{
cpu_thread_count_ = sysconf_nprocs_configured();
}
if (cpu_core_count_ <= 0)
{
cpu_core_count_ = 1;
}
return cpu_core_count_;
}
@@ -50,24 +112,23 @@ unsigned int b2::system_info::cpu_thread_count()
{
if (cpu_thread_count_ == 0)
{
#if defined(OS_MACOSX)
int out_hw_ncpu = 0;
size_t len_hw_ncpu = sizeof(out_hw_ncpu);
int result = ::sysctlbyname(
"hw.logicalcpu", &out_hw_ncpu, &len_hw_ncpu, nullptr, 0);
if (result == 0)
{
cpu_thread_count_ = out_hw_ncpu;
}
#elif defined(_SC_NPROCESSORS_ONLN)
cpu_thread_count_ = ::sysconf(_SC_NPROCESSORS_ONLN);
#else
cpu_thread_count_ = std::thread::hardware_concurrency();
#endif
if (cpu_thread_count_ <= 0)
{
cpu_thread_count_ = cpu_core_count();
}
cpu_thread_count_ = macosx_logicalcpu();
}
if (cpu_thread_count_ == 0)
{
cpu_thread_count_ = sched_affinity_cpu_count();
}
if (cpu_thread_count_ == 0)
{
cpu_thread_count_ = sysconf_nprocs_online();
}
if (cpu_thread_count_ == 0)
{
cpu_thread_count_ = std_thread_hardware_concurrency();
}
if (cpu_thread_count_ == 0)
{
cpu_thread_count_ = cpu_core_count();
}
return cpu_thread_count_;
}