From b7c3039eb290177e6f601e2f68ccabab479e4d01 Mon Sep 17 00:00:00 2001 From: greatroar <@> Date: Thu, 5 Mar 2020 18:50:55 +0100 Subject: [PATCH 1/3] Remove Go 1.5 compatibility code from PackerManager benchmark This alone is enough to speed up the benchmark by ~10%. --- internal/repository/packer_manager_test.go | 43 +++++----------------- 1 file changed, 9 insertions(+), 34 deletions(-) diff --git a/internal/repository/packer_manager_test.go b/internal/repository/packer_manager_test.go index 25d78f9b5..274d73552 100644 --- a/internal/repository/packer_manager_test.go +++ b/internal/repository/packer_manager_test.go @@ -14,31 +14,6 @@ import ( "github.com/restic/restic/internal/restic" ) -type randReader struct { - src rand.Source - rand *rand.Rand -} - -func newRandReader(src rand.Source) *randReader { - return &randReader{ - src: src, - rand: rand.New(src), - } -} - -// Read generates len(p) random bytes and writes them into p. It -// always returns len(p) and a nil error. -func (r *randReader) Read(p []byte) (n int, err error) { - for i := 0; i < len(p); i += 7 { - val := r.src.Int63() - for j := 0; i+j < len(p) && j < 7; j++ { - p[i+j] = byte(val) - val >>= 8 - } - } - return len(p), nil -} - func randomID(rd io.Reader) restic.ID { id := restic.ID{} _, err := io.ReadFull(rd, id[:]) @@ -73,17 +48,17 @@ func saveFile(t testing.TB, be Saver, length int, f *os.File, id restic.ID) { } } -func fillPacks(t testing.TB, rnd *randReader, be Saver, pm *packerManager, buf []byte) (bytes int) { +func fillPacks(t testing.TB, rnd *rand.Rand, be Saver, pm *packerManager, buf []byte) (bytes int) { for i := 0; i < 100; i++ { - l := rnd.rand.Intn(1 << 20) - seed := rnd.rand.Int63() + l := rnd.Intn(1 << 20) + seed := rnd.Int63() packer, err := pm.findPacker() if err != nil { t.Fatal(err) } - rd := newRandReader(rand.NewSource(seed)) + rd := rand.New(rand.NewSource(seed)) id := randomID(rd) buf = buf[:l] _, err = io.ReadFull(rd, buf) @@ -117,7 +92,7 @@ func fillPacks(t testing.TB, rnd *randReader, be Saver, pm *packerManager, buf [ return bytes } -func flushRemainingPacks(t testing.TB, rnd *randReader, be Saver, pm *packerManager) (bytes int) { +func flushRemainingPacks(t testing.TB, be Saver, pm *packerManager) (bytes int) { if pm.countPacker() > 0 { for _, packer := range pm.packers { n, err := packer.Finalize() @@ -135,7 +110,7 @@ func flushRemainingPacks(t testing.TB, rnd *randReader, be Saver, pm *packerMana } func TestPackerManager(t *testing.T) { - rnd := newRandReader(rand.NewSource(23)) + rnd := rand.New(rand.NewSource(23)) be := mem.New() pm := newPackerManager(be, crypto.NewRandomKey()) @@ -143,13 +118,13 @@ func TestPackerManager(t *testing.T) { blobBuf := make([]byte, maxBlobSize) bytes := fillPacks(t, rnd, be, pm, blobBuf) - bytes += flushRemainingPacks(t, rnd, be, pm) + bytes += flushRemainingPacks(t, be, pm) t.Logf("saved %d bytes", bytes) } func BenchmarkPackerManager(t *testing.B) { - rnd := newRandReader(rand.NewSource(23)) + rnd := rand.New(rand.NewSource(23)) be := &mock.Backend{ SaveFn: func(context.Context, restic.Handle, restic.RewindReader) error { return nil }, @@ -162,7 +137,7 @@ func BenchmarkPackerManager(t *testing.B) { bytes := 0 pm := newPackerManager(be, crypto.NewRandomKey()) bytes += fillPacks(t, rnd, be, pm, blobBuf) - bytes += flushRemainingPacks(t, rnd, be, pm) + bytes += flushRemainingPacks(t, be, pm) t.Logf("saved %d bytes", bytes) } } From b5926140615f060a8f4197db4771ef1f54ad47e4 Mon Sep 17 00:00:00 2001 From: greatroar <@> Date: Thu, 5 Mar 2020 20:54:52 +0100 Subject: [PATCH 2/3] Improve PackerManager benchmark MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The previous benchmark spent much of its time allocating RNGs and generating too many random numbers. It now spends 90% of its time hashing and half of the rest writing to files. name old time/op new time/op delta PackerManager-8 319ms ± 1% 247ms ± 1% -22.48% (p=0.000 n=20+18) name old speed new speed delta PackerManager-8 143MB/s ± 1% 213MB/s ± 1% +48.63% (p=0.000 n=10+18) name old alloc/op new alloc/op delta PackerManager-8 635kB ± 0% 92kB ± 0% -85.48% (p=0.000 n=10+19) name old allocs/op new allocs/op delta PackerManager-8 1.64k ± 0% 1.43k ± 0% -12.76% (p=0.000 n=10+20) --- internal/repository/packer_manager_test.go | 51 ++++++++++++++++------ 1 file changed, 37 insertions(+), 14 deletions(-) diff --git a/internal/repository/packer_manager_test.go b/internal/repository/packer_manager_test.go index 274d73552..d5ee9435c 100644 --- a/internal/repository/packer_manager_test.go +++ b/internal/repository/packer_manager_test.go @@ -5,6 +5,7 @@ import ( "io" "math/rand" "os" + "sync" "testing" "github.com/restic/restic/internal/backend/mem" @@ -25,6 +26,13 @@ func randomID(rd io.Reader) restic.ID { const maxBlobSize = 1 << 20 +func min(a, b int) int { + if a < b { + return a + } + return b +} + func saveFile(t testing.TB, be Saver, length int, f *os.File, id restic.ID) { h := restic.Handle{Type: restic.DataFile, Name: id.String()} t.Logf("save file %v", h) @@ -50,21 +58,17 @@ func saveFile(t testing.TB, be Saver, length int, f *os.File, id restic.ID) { func fillPacks(t testing.TB, rnd *rand.Rand, be Saver, pm *packerManager, buf []byte) (bytes int) { for i := 0; i < 100; i++ { - l := rnd.Intn(1 << 20) - seed := rnd.Int63() + l := rnd.Intn(maxBlobSize) packer, err := pm.findPacker() if err != nil { t.Fatal(err) } - rd := rand.New(rand.NewSource(seed)) - id := randomID(rd) + id := randomID(rnd) buf = buf[:l] - _, err = io.ReadFull(rd, buf) - if err != nil { - t.Fatal(err) - } + // Only change a few bytes so we know we're not benchmarking the RNG. + rnd.Read(buf[:min(l, 4)]) n, err := packer.Add(restic.DataBlob, id, buf) if err != nil { @@ -109,8 +113,20 @@ func flushRemainingPacks(t testing.TB, be Saver, pm *packerManager) (bytes int) return bytes } +const randomSeed = 23 + +var ( + once sync.Once + totalSize int64 +) + func TestPackerManager(t *testing.T) { - rnd := rand.New(rand.NewSource(23)) + bytes := testPackerManager(t) + once.Do(func() { totalSize = bytes }) +} + +func testPackerManager(t testing.TB) int64 { + rnd := rand.New(rand.NewSource(randomSeed)) be := mem.New() pm := newPackerManager(be, crypto.NewRandomKey()) @@ -121,23 +137,30 @@ func TestPackerManager(t *testing.T) { bytes += flushRemainingPacks(t, be, pm) t.Logf("saved %d bytes", bytes) + return int64(bytes) } func BenchmarkPackerManager(t *testing.B) { - rnd := rand.New(rand.NewSource(23)) + // Run testPackerManager if it hasn't run already, to set totalSize. + once.Do(func() { + totalSize = testPackerManager(t) + }) + + rnd := rand.New(rand.NewSource(randomSeed)) be := &mock.Backend{ SaveFn: func(context.Context, restic.Handle, restic.RewindReader) error { return nil }, } blobBuf := make([]byte, maxBlobSize) + t.ReportAllocs() + t.SetBytes(totalSize) t.ResetTimer() for i := 0; i < t.N; i++ { - bytes := 0 + rnd.Seed(randomSeed) pm := newPackerManager(be, crypto.NewRandomKey()) - bytes += fillPacks(t, rnd, be, pm, blobBuf) - bytes += flushRemainingPacks(t, be, pm) - t.Logf("saved %d bytes", bytes) + fillPacks(t, rnd, be, pm, blobBuf) + flushRemainingPacks(t, be, pm) } } From 41fee11f66d5ecc498de18216cb308fba5ef0114 Mon Sep 17 00:00:00 2001 From: greatroar <@> Date: Thu, 5 Mar 2020 21:06:16 +0100 Subject: [PATCH 3/3] Micro-optimization for hashing.Writer/PackerManager MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit name old time/op new time/op delta PackerManager-8 247ms ± 1% 246ms ± 1% -0.43% (p=0.001 n=18+18) name old speed new speed delta PackerManager-8 213MB/s ± 1% 214MB/s ± 1% +0.43% (p=0.001 n=18+18) name old alloc/op new alloc/op delta PackerManager-8 92.2kB ± 0% 91.5kB ± 0% -0.82% (p=0.000 n=19+20) name old allocs/op new allocs/op delta PackerManager-8 1.43k ± 0% 1.41k ± 0% -1.67% (p=0.000 n=20+20) --- internal/hashing/writer.go | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/internal/hashing/writer.go b/internal/hashing/writer.go index 2940a6271..8eb157a9f 100644 --- a/internal/hashing/writer.go +++ b/internal/hashing/writer.go @@ -15,13 +15,14 @@ type Writer struct { func NewWriter(w io.Writer, h hash.Hash) *Writer { return &Writer{ h: h, - w: io.MultiWriter(w, h), + w: w, } } // Write wraps the write method of the underlying writer and also hashes all data. func (h *Writer) Write(p []byte) (int, error) { n, err := h.w.Write(p) + h.h.Write(p[:n]) return n, err }