#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright (C) 2018 ScyllaDB
#

#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
#

# Guess and print out a good number of compiler jobs to
# run. Note that on an interactive desktop you will want
# to reduce this to allow more memory for your desktop,
# to avoid swapping. This is oriented at continuous
# integration machines that do not serve an interactive
# load as well.

import os

procs = os.sysconf('SC_NPROCESSORS_ONLN')
mem = os.sysconf('SC_PHYS_PAGES') * os.sysconf('SC_PAGESIZE')

mem_reserve = 1000000000
job_mem = 4000000000

jobs = min(procs, (mem-mem_reserve) // job_mem)
jobs = max(jobs, 1)

print(jobs)
