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build / toolchain / get_concurrent_links.py [blame]
#!/usr/bin/env python3
# Copyright 2014 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# This script computs the number of concurrent links we want to run in the build
# as a function of machine spec. It's based on GetDefaultConcurrentLinks in GYP.
import argparse
import multiprocessing
import os
import re
import subprocess
import sys
sys.path.insert(1, os.path.join(os.path.dirname(__file__), '..'))
import gn_helpers
def _GetTotalMemoryInBytes():
if sys.platform in ('win32', 'cygwin'):
import ctypes
class MEMORYSTATUSEX(ctypes.Structure):
_fields_ = [
("dwLength", ctypes.c_ulong),
("dwMemoryLoad", ctypes.c_ulong),
("ullTotalPhys", ctypes.c_ulonglong),
("ullAvailPhys", ctypes.c_ulonglong),
("ullTotalPageFile", ctypes.c_ulonglong),
("ullAvailPageFile", ctypes.c_ulonglong),
("ullTotalVirtual", ctypes.c_ulonglong),
("ullAvailVirtual", ctypes.c_ulonglong),
("sullAvailExtendedVirtual", ctypes.c_ulonglong),
]
stat = MEMORYSTATUSEX(dwLength=ctypes.sizeof(MEMORYSTATUSEX))
ctypes.windll.kernel32.GlobalMemoryStatusEx(ctypes.byref(stat))
return stat.ullTotalPhys
elif sys.platform.startswith('linux'):
if os.path.exists("/proc/meminfo"):
with open("/proc/meminfo") as meminfo:
memtotal_re = re.compile(r'^MemTotal:\s*(\d*)\s*kB')
for line in meminfo:
match = memtotal_re.match(line)
if not match:
continue
return float(match.group(1)) * 2**10
elif sys.platform == 'darwin':
try:
return int(subprocess.check_output(['sysctl', '-n', 'hw.memsize']))
except Exception:
return 0
# TODO(scottmg): Implement this for other platforms.
return 0
def _GetDefaultConcurrentLinks(per_link_gb, reserve_gb, thin_lto_type,
secondary_per_link_gb, override_ram_in_gb):
explanation = []
explanation.append(
'per_link_gb={} reserve_gb={} secondary_per_link_gb={}'.format(
per_link_gb, reserve_gb, secondary_per_link_gb))
if override_ram_in_gb:
mem_total_gb = override_ram_in_gb
else:
mem_total_gb = float(_GetTotalMemoryInBytes()) / 2**30
adjusted_mem_total_gb = max(0, mem_total_gb - reserve_gb)
# Ensure that there is at least as many links allocated for the secondary as
# there is for the primary. The secondary link usually uses fewer gbs.
mem_cap = int(
max(1, adjusted_mem_total_gb / (per_link_gb + secondary_per_link_gb)))
try:
cpu_count = multiprocessing.cpu_count()
except:
cpu_count = 1
# A local LTO links saturate all cores, but only for some amount of the link.
cpu_cap = cpu_count
if thin_lto_type is not None:
assert thin_lto_type == 'local'
cpu_cap = min(cpu_count, 6)
explanation.append(
'cpu_count={} cpu_cap={} mem_total_gb={:.1f}GiB adjusted_mem_total_gb={:.1f}GiB'
.format(cpu_count, cpu_cap, mem_total_gb, adjusted_mem_total_gb))
num_links = min(mem_cap, cpu_cap)
if num_links == cpu_cap:
if cpu_cap == cpu_count:
reason = 'cpu_count'
else:
reason = 'cpu_cap (thinlto)'
else:
reason = 'RAM'
# static link see too many open files if we have many concurrent links.
# ref: http://b/233068481
if num_links > 30:
num_links = 30
reason = 'nofile'
explanation.append('concurrent_links={} (reason: {})'.format(
num_links, reason))
# Use remaining RAM for a secondary pool if needed.
if secondary_per_link_gb:
mem_remaining = adjusted_mem_total_gb - num_links * per_link_gb
secondary_size = int(max(0, mem_remaining / secondary_per_link_gb))
if secondary_size > cpu_count:
secondary_size = cpu_count
reason = 'cpu_count'
else:
reason = 'mem_remaining={:.1f}GiB'.format(mem_remaining)
explanation.append('secondary_size={} (reason: {})'.format(
secondary_size, reason))
else:
secondary_size = 0
return num_links, secondary_size, explanation
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--mem_per_link_gb', type=int, default=8)
parser.add_argument('--reserve_mem_gb', type=int, default=0)
parser.add_argument('--secondary_mem_per_link', type=int, default=0)
parser.add_argument('--override-ram-in-gb-for-testing', type=float, default=0)
parser.add_argument('--thin-lto')
options = parser.parse_args()
primary_pool_size, secondary_pool_size, explanation = (
_GetDefaultConcurrentLinks(options.mem_per_link_gb,
options.reserve_mem_gb, options.thin_lto,
options.secondary_mem_per_link,
options.override_ram_in_gb_for_testing))
if options.override_ram_in_gb_for_testing:
print('primary={} secondary={} explanation={}'.format(
primary_pool_size, secondary_pool_size, explanation))
else:
sys.stdout.write(
gn_helpers.ToGNString({
'primary_pool_size': primary_pool_size,
'secondary_pool_size': secondary_pool_size,
'explanation': explanation,
}))
return 0
if __name__ == '__main__':
sys.exit(main())