cmd/trace: revert internal/traceparser

The performance improvement is not as big as we hoped.
Until the API is feature complete, we postpone the release
and avoid added complexity.

This change was prepared by reverting all the changes affected
src/cmd/trace and src/internal/traceparser packages after
golang.org/cl/137635, and then bringing back MMU computation
APIs (originally in src/internal/traceparser) to the
src/internal/trace package.

Revert "cmd/trace: use new traceparser to parse the raw trace files"
This reverts https://golang.org/cl/145457
  (commit 08816cb8d7ed16b9c804587ff02c1ad1c3af6cd5).

Revert "internal/traceparser: provide parser that uses less space and parses segments of runtime trace files"
This reverts https://golang.org/cl/137635
  (commit daaf361f74c3665bcb364356c5a9dd9f536c78c3).

Change-Id: Ic2a068a7dbaf4053cd9674ca7bde9c58e74385b4
Reviewed-on: https://go-review.googlesource.com/c/150517
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

1 files changed, 26 insertions, 38 deletions

diff --git a/src/cmd/trace/pprof.go b/src/cmd/trace/pprof.go
index cf74fe56ae..3389d2799b 100644
--- a/src/cmd/trace/pprof.go
+++ b/src/cmd/trace/pprof.go
@@ -9,6 +9,7 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"internal/trace"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -20,8 +21,6 @@ import (
 	"strconv"
 	"time"
 
-	trace "internal/traceparser"
-
 	"github.com/google/pprof/profile"
 )
 
@@ -61,22 +60,22 @@ type interval struct {
 	begin, end int64 // nanoseconds.
 }
 
-func pprofByGoroutine(compute func(io.Writer, map[uint64][]interval, *trace.Parsed) error) func(w io.Writer, r *http.Request) error {
+func pprofByGoroutine(compute func(io.Writer, map[uint64][]interval, []*trace.Event) error) func(w io.Writer, r *http.Request) error {
 	return func(w io.Writer, r *http.Request) error {
 		id := r.FormValue("id")
-		res, err := parseTrace()
+		events, err := parseEvents()
 		if err != nil {
 			return err
 		}
-		gToIntervals, err := pprofMatchingGoroutines(id, res)
+		gToIntervals, err := pprofMatchingGoroutines(id, events)
 		if err != nil {
 			return err
 		}
-		return compute(w, gToIntervals, res)
+		return compute(w, gToIntervals, events)
 	}
 }
 
-func pprofByRegion(compute func(io.Writer, map[uint64][]interval, *trace.Parsed) error) func(w io.Writer, r *http.Request) error {
+func pprofByRegion(compute func(io.Writer, map[uint64][]interval, []*trace.Event) error) func(w io.Writer, r *http.Request) error {
 	return func(w io.Writer, r *http.Request) error {
 		filter, err := newRegionFilter(r)
 		if err != nil {
@@ -86,7 +85,7 @@ func pprofByRegion(compute func(io.Writer, map[uint64][]interval, *trace.Parsed)
 		if err != nil {
 			return err
 		}
-		events, _ := parseTrace()
+		events, _ := parseEvents()
 
 		return compute(w, gToIntervals, events)
 	}
@@ -95,7 +94,7 @@ func pprofByRegion(compute func(io.Writer, map[uint64][]interval, *trace.Parsed)
 // pprofMatchingGoroutines parses the goroutine type id string (i.e. pc)
 // and returns the ids of goroutines of the matching type and its interval.
 // If the id string is empty, returns nil without an error.
-func pprofMatchingGoroutines(id string, p *trace.Parsed) (map[uint64][]interval, error) {
+func pprofMatchingGoroutines(id string, events []*trace.Event) (map[uint64][]interval, error) {
 	if id == "" {
 		return nil, nil
 	}
@@ -103,7 +102,7 @@ func pprofMatchingGoroutines(id string, p *trace.Parsed) (map[uint64][]interval,
 	if err != nil {
 		return nil, fmt.Errorf("invalid goroutine type: %v", id)
 	}
-	analyzeGoroutines(p)
+	analyzeGoroutines(events)
 	var res map[uint64][]interval
 	for _, g := range gs {
 		if g.PC != pc {
@@ -172,25 +171,17 @@ func pprofMatchingRegions(filter *regionFilter) (map[uint64][]interval, error) {
 	return gToIntervals, nil
 }
 
-func stklen(p *trace.Parsed, ev *trace.Event) int {
-	if ev.StkID == 0 {
-		return 0
-	}
-	return len(p.Stacks[ev.StkID])
-}
-
 // computePprofIO generates IO pprof-like profile (time spent in IO wait, currently only network blocking event).
-func computePprofIO(w io.Writer, gToIntervals map[uint64][]interval, res *trace.Parsed) error {
-	events := res.Events
-	prof := make(map[uint32]Record)
+func computePprofIO(w io.Writer, gToIntervals map[uint64][]interval, events []*trace.Event) error {
+	prof := make(map[uint64]Record)
 	for _, ev := range events {
-		if ev.Type != trace.EvGoBlockNet || ev.Link == nil || ev.StkID == 0 || stklen(res, ev) == 0 {
+		if ev.Type != trace.EvGoBlockNet || ev.Link == nil || ev.StkID == 0 || len(ev.Stk) == 0 {
 			continue
 		}
 		overlapping := pprofOverlappingDuration(gToIntervals, ev)
 		if overlapping > 0 {
 			rec := prof[ev.StkID]
-			rec.stk = res.Stacks[ev.StkID]
+			rec.stk = ev.Stk
 			rec.n++
 			rec.time += overlapping.Nanoseconds()
 			prof[ev.StkID] = rec
@@ -200,9 +191,8 @@ func computePprofIO(w io.Writer, gToIntervals map[uint64][]interval, res *trace.
 }
 
 // computePprofBlock generates blocking pprof-like profile (time spent blocked on synchronization primitives).
-func computePprofBlock(w io.Writer, gToIntervals map[uint64][]interval, res *trace.Parsed) error {
-	events := res.Events
-	prof := make(map[uint32]Record)
+func computePprofBlock(w io.Writer, gToIntervals map[uint64][]interval, events []*trace.Event) error {
+	prof := make(map[uint64]Record)
 	for _, ev := range events {
 		switch ev.Type {
 		case trace.EvGoBlockSend, trace.EvGoBlockRecv, trace.EvGoBlockSelect,
@@ -213,13 +203,13 @@ func computePprofBlock(w io.Writer, gToIntervals map[uint64][]interval, res *tra
 		default:
 			continue
 		}
-		if ev.Link == nil || ev.StkID == 0 || stklen(res, ev) == 0 {
+		if ev.Link == nil || ev.StkID == 0 || len(ev.Stk) == 0 {
 			continue
 		}
 		overlapping := pprofOverlappingDuration(gToIntervals, ev)
 		if overlapping > 0 {
 			rec := prof[ev.StkID]
-			rec.stk = res.Stacks[ev.StkID]
+			rec.stk = ev.Stk
 			rec.n++
 			rec.time += overlapping.Nanoseconds()
 			prof[ev.StkID] = rec
@@ -229,17 +219,16 @@ func computePprofBlock(w io.Writer, gToIntervals map[uint64][]interval, res *tra
 }
 
 // computePprofSyscall generates syscall pprof-like profile (time spent blocked in syscalls).
-func computePprofSyscall(w io.Writer, gToIntervals map[uint64][]interval, res *trace.Parsed) error {
-	events := res.Events
-	prof := make(map[uint32]Record)
+func computePprofSyscall(w io.Writer, gToIntervals map[uint64][]interval, events []*trace.Event) error {
+	prof := make(map[uint64]Record)
 	for _, ev := range events {
-		if ev.Type != trace.EvGoSysCall || ev.Link == nil || ev.StkID == 0 || stklen(res, ev) == 0 {
+		if ev.Type != trace.EvGoSysCall || ev.Link == nil || ev.StkID == 0 || len(ev.Stk) == 0 {
 			continue
 		}
 		overlapping := pprofOverlappingDuration(gToIntervals, ev)
 		if overlapping > 0 {
 			rec := prof[ev.StkID]
-			rec.stk = res.Stacks[ev.StkID]
+			rec.stk = ev.Stk
 			rec.n++
 			rec.time += overlapping.Nanoseconds()
 			prof[ev.StkID] = rec
@@ -250,18 +239,17 @@ func computePprofSyscall(w io.Writer, gToIntervals map[uint64][]interval, res *t
 
 // computePprofSched generates scheduler latency pprof-like profile
 // (time between a goroutine become runnable and actually scheduled for execution).
-func computePprofSched(w io.Writer, gToIntervals map[uint64][]interval, res *trace.Parsed) error {
-	events := res.Events
-	prof := make(map[uint32]Record)
+func computePprofSched(w io.Writer, gToIntervals map[uint64][]interval, events []*trace.Event) error {
+	prof := make(map[uint64]Record)
 	for _, ev := range events {
 		if (ev.Type != trace.EvGoUnblock && ev.Type != trace.EvGoCreate) ||
-			ev.Link == nil || ev.StkID == 0 || stklen(res, ev) == 0 {
+			ev.Link == nil || ev.StkID == 0 || len(ev.Stk) == 0 {
 			continue
 		}
 		overlapping := pprofOverlappingDuration(gToIntervals, ev)
 		if overlapping > 0 {
 			rec := prof[ev.StkID]
-			rec.stk = res.Stacks[ev.StkID]
+			rec.stk = ev.Stk
 			rec.n++
 			rec.time += overlapping.Nanoseconds()
 			prof[ev.StkID] = rec
@@ -339,7 +327,7 @@ func serveSVGProfile(prof func(w io.Writer, r *http.Request) error) http.Handler
 	}
 }
 
-func buildProfile(prof map[uint32]Record) *profile.Profile {
+func buildProfile(prof map[uint64]Record) *profile.Profile {
 	p := &profile.Profile{
 		PeriodType: &profile.ValueType{Type: "trace", Unit: "count"},
 		Period:     1,