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runtime: remove unused GC timers

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During development some tracing routines were added that are not
needed in the release. These included GCstarttimes, GCendtimes, and
GCprinttimes.
Fixes #10462

Change-Id: I0788e6409d61038571a5ae0cbbab793102df0a65
Reviewed-on: https://go-review.googlesource.com/9689
Reviewed-by: Austin Clements <austin@google.com>
This commit is contained in:
Rick Hudson 2015-05-04 14:03:07 -04:00
parent 9d0a2e4d6e
commit 1845314560
1 changed files with 0 additions and 122 deletions
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122
src/runtime/mgc.go
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@ -785,10 +785,8 @@ func gc(mode int) {
sweep.nbgsweep++
}
gctimer.count++
if mode == gcBackgroundMode {
gcBgMarkStartWorkers()
gctimer.cycle.sweepterm = nanotime()
}
if debug.gctrace > 0 {
stwprocs, maxprocs = gcprocs(), gomaxprocs
@ -825,12 +823,10 @@ func gc(mode int) {
// Concurrent scan.
starttheworld()
gctimer.cycle.scan = nanotime()
if debug.gctrace > 0 {
tScan = nanotime()
}
gcscan_m()
gctimer.cycle.installmarkwb = nanotime()
// Enter mark phase. This enables write
// barriers.
@ -850,7 +846,6 @@ func gc(mode int) {
// black invariant. Mutator assists and mark workers
// can now be enabled to safely blacken grey objects.
atomicstore(&gcBlackenEnabled, 1)
gctimer.cycle.mark = nanotime()
if debug.gctrace > 0 {
tMark = nanotime()
}
@ -868,7 +863,6 @@ func gc(mode int) {
work.bgMarkWake.g = nil
// Begin mark termination.
gctimer.cycle.markterm = nanotime()
if debug.gctrace > 0 {
tMarkTerm = nanotime()
}
@ -961,20 +955,8 @@ func gc(mode int) {
// all done
mp.preemptoff = ""
if mode == gcBackgroundMode {
gctimer.cycle.sweep = nanotime()
}
semrelease(&worldsema)
if mode == gcBackgroundMode {
if gctimer.verbose > 1 {
GCprinttimes()
} else if gctimer.verbose > 0 {
calctimes() // ignore result
}
}
if gcphase != _GCoff {
throw("gc done but gcphase != _GCoff")
}
@ -1490,110 +1472,6 @@ func gchelperstart() {
}
}
// gcchronograph holds timer information related to GC phases
// max records the maximum time spent in each GC phase since GCstarttimes.
// total records the total time spent in each GC phase since GCstarttimes.
// cycle records the absolute time (as returned by nanoseconds()) that each GC phase last started at.
type gcchronograph struct {
count int64
verbose int64
maxpause int64
max gctimes
total gctimes
cycle gctimes
}
// gctimes records the time in nanoseconds of each phase of the concurrent GC.
type gctimes struct {
sweepterm int64 // stw
scan int64
installmarkwb int64 // stw
mark int64
markterm int64 // stw
sweep int64
}
var gctimer gcchronograph
// GCstarttimes initializes the gc times. All previous times are lost.
func GCstarttimes(verbose int64) {
gctimer = gcchronograph{verbose: verbose}
}
// GCendtimes stops the gc timers.
func GCendtimes() {
gctimer.verbose = 0
}
// calctimes converts gctimer.cycle into the elapsed times, updates gctimer.total
// and updates gctimer.max with the max pause time.
func calctimes() gctimes {
var times gctimes
var max = func(a, b int64) int64 {
if a > b {
return a
}
return b
}
times.sweepterm = gctimer.cycle.scan - gctimer.cycle.sweepterm
gctimer.total.sweepterm += times.sweepterm
gctimer.max.sweepterm = max(gctimer.max.sweepterm, times.sweepterm)
gctimer.maxpause = max(gctimer.maxpause, gctimer.max.sweepterm)
times.scan = gctimer.cycle.installmarkwb - gctimer.cycle.scan
gctimer.total.scan += times.scan
gctimer.max.scan = max(gctimer.max.scan, times.scan)
times.installmarkwb = gctimer.cycle.mark - gctimer.cycle.installmarkwb
gctimer.total.installmarkwb += times.installmarkwb
gctimer.max.installmarkwb = max(gctimer.max.installmarkwb, times.installmarkwb)
gctimer.maxpause = max(gctimer.maxpause, gctimer.max.installmarkwb)
times.mark = gctimer.cycle.markterm - gctimer.cycle.mark
gctimer.total.mark += times.mark
gctimer.max.mark = max(gctimer.max.mark, times.mark)
times.markterm = gctimer.cycle.sweep - gctimer.cycle.markterm
gctimer.total.markterm += times.markterm
gctimer.max.markterm = max(gctimer.max.markterm, times.markterm)
gctimer.maxpause = max(gctimer.maxpause, gctimer.max.markterm)
return times
}
// GCprinttimes prints latency information in nanoseconds about various
// phases in the GC. The information for each phase includes the maximum pause
// and total time since the most recent call to GCstarttimes as well as
// the information from the most recent Concurent GC cycle. Calls from the
// application to runtime.GC() are ignored.
func GCprinttimes() {
if gctimer.verbose == 0 {
println("GC timers not enabled")
return
}
// Explicitly put times on the heap so printPhase can use it.
times := new(gctimes)
*times = calctimes()
cycletime := gctimer.cycle.sweep - gctimer.cycle.sweepterm
pause := times.sweepterm + times.installmarkwb + times.markterm
gomaxprocs := GOMAXPROCS(-1)
printlock()
print("GC: #", gctimer.count, " ", cycletime, "ns @", gctimer.cycle.sweepterm, " pause=", pause, " maxpause=", gctimer.maxpause, " goroutines=", allglen, " gomaxprocs=", gomaxprocs, "\n")
printPhase := func(label string, get func(*gctimes) int64, procs int) {
print("GC: ", label, " ", get(times), "ns\tmax=", get(&gctimer.max), "\ttotal=", get(&gctimer.total), "\tprocs=", procs, "\n")
}
printPhase("sweep term:", func(t *gctimes) int64 { return t.sweepterm }, gomaxprocs)
printPhase("scan: ", func(t *gctimes) int64 { return t.scan }, 1)
printPhase("install wb:", func(t *gctimes) int64 { return t.installmarkwb }, gomaxprocs)
printPhase("mark: ", func(t *gctimes) int64 { return t.mark }, 1)
printPhase("mark term: ", func(t *gctimes) int64 { return t.markterm }, gomaxprocs)
printunlock()
}
// itoaDiv formats val/(10**dec) into buf.
func itoaDiv(buf []byte, val uint64, dec int) []byte {
i := len(buf) - 1