lotus/system/resources.go
2020-12-02 22:26:30 +00:00

64 lines
1.9 KiB
Go

package system
import (
"os"
"github.com/dustin/go-humanize"
"github.com/elastic/gosigar"
logging "github.com/ipfs/go-log/v2"
)
var (
logSystem = logging.Logger("system")
)
// EnvMaximumHeap is name of the environment variable with which the user can
// specify a maximum heap size to abide by. The value of the env variable should
// be in bytes, or in SI bytes (e.g. 32GiB).
const EnvMaximumHeap = "LOTUS_MAX_HEAP"
// MemoryConstraints represents resource constraints that Lotus and the go
// runtime should abide by. It is a singleton object that's populated on
// initialization, and can be used by components for size calculations
// (e.g. caches).
type MemoryConstraints struct {
// MaxHeapMem is the maximum heap memory that has been set by the user
// through the LOTUS_MAX_HEAP env variable. If zero, there is no max heap
// limit set.
MaxHeapMem uint64
// TotalSystemMem is the total system memory as reported by go-sigar. If
// zero, it was impossible to determine the total system memory.
TotalSystemMem uint64
// EffectiveMemLimit is the memory limit in effect, in bytes.
//
// In order of precedence:
// 1. MaxHeapMem if non-zero.
// 2. TotalSystemMem if non-zero.
// 3. Zero (no known limit).
EffectiveMemLimit uint64
}
// GetMemoryConstraints returns the memory constraints for this process.
func GetMemoryConstraints() (ret MemoryConstraints) {
var mem gosigar.Mem
if err := mem.Get(); err != nil {
logSystem.Warnf("failed to acquire total system memory: %s", err)
} else {
ret.TotalSystemMem = mem.Total
ret.EffectiveMemLimit = mem.Total
}
if v := os.Getenv(EnvMaximumHeap); v != "" {
bytes, err := humanize.ParseBytes(v)
if err != nil {
logSystem.Warnf("failed to parse %s env variable with value %s: %s; ignoring max heap limit", EnvMaximumHeap, v, err)
} else {
ret.MaxHeapMem = bytes
ret.EffectiveMemLimit = bytes
}
}
return ret
}