cmd, consensus: add option to disable mmap for DAG caches/datasets (#20484)

* cmd, consensus: add option to disable mmap for DAG caches/datasets

* consensus: add benchmarks for mmap with/with lock
This commit is contained in:
Hanjiang Yu
2020-03-31 16:44:04 +08:00
committed by GitHub
parent 76eed9e50d
commit 8f05cfa122
8 changed files with 108 additions and 48 deletions

View File

@ -48,7 +48,7 @@ var (
two256 = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
// sharedEthash is a full instance that can be shared between multiple users.
sharedEthash = New(Config{"", 3, 0, "", 1, 0, ModeNormal, nil}, nil, false)
sharedEthash = New(Config{"", 3, 0, false, "", 1, 0, false, ModeNormal, nil}, nil, false)
// algorithmRevision is the data structure version used for file naming.
algorithmRevision = 23
@ -65,7 +65,7 @@ func isLittleEndian() bool {
}
// memoryMap tries to memory map a file of uint32s for read only access.
func memoryMap(path string) (*os.File, mmap.MMap, []uint32, error) {
func memoryMap(path string, lock bool) (*os.File, mmap.MMap, []uint32, error) {
file, err := os.OpenFile(path, os.O_RDONLY, 0644)
if err != nil {
return nil, nil, nil, err
@ -82,6 +82,13 @@ func memoryMap(path string) (*os.File, mmap.MMap, []uint32, error) {
return nil, nil, nil, ErrInvalidDumpMagic
}
}
if lock {
if err := mem.Lock(); err != nil {
mem.Unmap()
file.Close()
return nil, nil, nil, err
}
}
return file, mem, buffer[len(dumpMagic):], err
}
@ -107,7 +114,7 @@ func memoryMapFile(file *os.File, write bool) (mmap.MMap, []uint32, error) {
// memoryMapAndGenerate tries to memory map a temporary file of uint32s for write
// access, fill it with the data from a generator and then move it into the final
// path requested.
func memoryMapAndGenerate(path string, size uint64, generator func(buffer []uint32)) (*os.File, mmap.MMap, []uint32, error) {
func memoryMapAndGenerate(path string, size uint64, lock bool, generator func(buffer []uint32)) (*os.File, mmap.MMap, []uint32, error) {
// Ensure the data folder exists
if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
return nil, nil, nil, err
@ -142,7 +149,7 @@ func memoryMapAndGenerate(path string, size uint64, generator func(buffer []uint
if err := os.Rename(temp, path); err != nil {
return nil, nil, nil, err
}
return memoryMap(path)
return memoryMap(path, lock)
}
// lru tracks caches or datasets by their last use time, keeping at most N of them.
@ -213,7 +220,7 @@ func newCache(epoch uint64) interface{} {
}
// generate ensures that the cache content is generated before use.
func (c *cache) generate(dir string, limit int, test bool) {
func (c *cache) generate(dir string, limit int, lock bool, test bool) {
c.once.Do(func() {
size := cacheSize(c.epoch*epochLength + 1)
seed := seedHash(c.epoch*epochLength + 1)
@ -240,7 +247,7 @@ func (c *cache) generate(dir string, limit int, test bool) {
// Try to load the file from disk and memory map it
var err error
c.dump, c.mmap, c.cache, err = memoryMap(path)
c.dump, c.mmap, c.cache, err = memoryMap(path, lock)
if err == nil {
logger.Debug("Loaded old ethash cache from disk")
return
@ -248,7 +255,7 @@ func (c *cache) generate(dir string, limit int, test bool) {
logger.Debug("Failed to load old ethash cache", "err", err)
// No previous cache available, create a new cache file to fill
c.dump, c.mmap, c.cache, err = memoryMapAndGenerate(path, size, func(buffer []uint32) { generateCache(buffer, c.epoch, seed) })
c.dump, c.mmap, c.cache, err = memoryMapAndGenerate(path, size, lock, func(buffer []uint32) { generateCache(buffer, c.epoch, seed) })
if err != nil {
logger.Error("Failed to generate mapped ethash cache", "err", err)
@ -290,7 +297,7 @@ func newDataset(epoch uint64) interface{} {
}
// generate ensures that the dataset content is generated before use.
func (d *dataset) generate(dir string, limit int, test bool) {
func (d *dataset) generate(dir string, limit int, lock bool, test bool) {
d.once.Do(func() {
// Mark the dataset generated after we're done. This is needed for remote
defer atomic.StoreUint32(&d.done, 1)
@ -326,7 +333,7 @@ func (d *dataset) generate(dir string, limit int, test bool) {
// Try to load the file from disk and memory map it
var err error
d.dump, d.mmap, d.dataset, err = memoryMap(path)
d.dump, d.mmap, d.dataset, err = memoryMap(path, lock)
if err == nil {
logger.Debug("Loaded old ethash dataset from disk")
return
@ -337,7 +344,7 @@ func (d *dataset) generate(dir string, limit int, test bool) {
cache := make([]uint32, csize/4)
generateCache(cache, d.epoch, seed)
d.dump, d.mmap, d.dataset, err = memoryMapAndGenerate(path, dsize, func(buffer []uint32) { generateDataset(buffer, d.epoch, cache) })
d.dump, d.mmap, d.dataset, err = memoryMapAndGenerate(path, dsize, lock, func(buffer []uint32) { generateDataset(buffer, d.epoch, cache) })
if err != nil {
logger.Error("Failed to generate mapped ethash dataset", "err", err)
@ -372,13 +379,13 @@ func (d *dataset) finalizer() {
// MakeCache generates a new ethash cache and optionally stores it to disk.
func MakeCache(block uint64, dir string) {
c := cache{epoch: block / epochLength}
c.generate(dir, math.MaxInt32, false)
c.generate(dir, math.MaxInt32, false, false)
}
// MakeDataset generates a new ethash dataset and optionally stores it to disk.
func MakeDataset(block uint64, dir string) {
d := dataset{epoch: block / epochLength}
d.generate(dir, math.MaxInt32, false)
d.generate(dir, math.MaxInt32, false, false)
}
// Mode defines the type and amount of PoW verification an ethash engine makes.
@ -394,13 +401,15 @@ const (
// Config are the configuration parameters of the ethash.
type Config struct {
CacheDir string
CachesInMem int
CachesOnDisk int
DatasetDir string
DatasetsInMem int
DatasetsOnDisk int
PowMode Mode
CacheDir string
CachesInMem int
CachesOnDisk int
CachesLockMmap bool
DatasetDir string
DatasetsInMem int
DatasetsOnDisk int
DatasetsLockMmap bool
PowMode Mode
Log log.Logger `toml:"-"`
}
@ -549,12 +558,12 @@ func (ethash *Ethash) cache(block uint64) *cache {
current := currentI.(*cache)
// Wait for generation finish.
current.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
current.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.CachesLockMmap, ethash.config.PowMode == ModeTest)
// If we need a new future cache, now's a good time to regenerate it.
if futureI != nil {
future := futureI.(*cache)
go future.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
go future.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.CachesLockMmap, ethash.config.PowMode == ModeTest)
}
return current
}
@ -574,20 +583,20 @@ func (ethash *Ethash) dataset(block uint64, async bool) *dataset {
// If async is specified, generate everything in a background thread
if async && !current.generated() {
go func() {
current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.DatasetsLockMmap, ethash.config.PowMode == ModeTest)
if futureI != nil {
future := futureI.(*dataset)
future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.DatasetsLockMmap, ethash.config.PowMode == ModeTest)
}
}()
} else {
// Either blocking generation was requested, or already done
current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.DatasetsLockMmap, ethash.config.PowMode == ModeTest)
if futureI != nil {
future := futureI.(*dataset)
go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.DatasetsLockMmap, ethash.config.PowMode == ModeTest)
}
}
return current