minio/pkg/sys/stats_linux.go

88 lines
2.5 KiB
Go

// +build linux,!arm,!386
// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program 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.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package sys
import (
"os"
"syscall"
"github.com/minio/minio/pkg/cgroup"
)
// Get the final system memory limit chosen by the user.
// by default without any configuration on a vanilla Linux
// system you would see physical RAM limit. If cgroup
// is configured at some point in time this function
// would return the memory limit chosen for the given pid.
func getMemoryLimit() (sysLimit uint64, err error) {
if sysLimit, err = getSysinfoMemoryLimit(); err != nil {
// Physical memory info is not accessible, just exit here.
return 0, err
}
// Following code is deliberately ignoring the error.
cGroupLimit, gerr := cgroup.GetMemoryLimit(os.Getpid())
if gerr != nil {
// Upon error just return system limit.
return sysLimit, nil
}
// cgroup limit is lesser than system limit means
// user wants to limit the memory usage further
// treat cgroup limit as the system limit.
if cGroupLimit <= sysLimit {
sysLimit = cGroupLimit
}
// Final system limit.
return sysLimit, nil
}
// Get physical RAM size of the node.
func getSysinfoMemoryLimit() (limit uint64, err error) {
var si syscall.Sysinfo_t
if err = syscall.Sysinfo(&si); err != nil {
return 0, err
}
// Some fields in syscall.Sysinfo_t have different integer sizes
// in different platform architectures. Cast all fields to uint64.
unit := si.Unit
totalRAM := si.Totalram
// Total RAM is always the multiplicative value
// of unit size and total ram.
return uint64(unit) * uint64(totalRAM), nil
}
// GetStats - return system statistics, currently only
// supported value is TotalRAM.
func GetStats() (stats Stats, err error) {
var limit uint64
limit, err = getMemoryLimit()
if err != nil {
return Stats{}, err
}
stats.TotalRAM = limit
return stats, nil
}