runtime: improve tickspersecond

[gostls13.git] / src / runtime / mprof.go

diff --git a/src/runtime/mprof.go b/src/runtime/mprof.go
index 174ceb0a1f49c60ad36fa0d8e4f78d304eec74cc..ef485a3cfcdfb9d4ccbd28a038b481e8028eea81 100644 (file)
--- a/src/runtime/mprof.go
+++ b/src/runtime/mprof.go
@@ -39,7 +39,10 @@ const (
        // size of bucket hash table
        buckHashSize = 179999
 
-       // max depth of stack to record in bucket
+       // maxStack is the max depth of stack to record in bucket.
+       // Note that it's only used internally as a guard against
+       // wildly out-of-bounds slicing of the PCs that come after
+       // a bucket struct, and it could increase in the future.
        maxStack = 32
 )
 
@@ -468,7 +471,7 @@ func SetBlockProfileRate(rate int) {
                r = 1 // profile everything
        } else {
                // convert ns to cycles, use float64 to prevent overflow during multiplication
-               r = int64(float64(rate) * float64(tickspersecond()) / (1000 * 1000 * 1000))
+               r = int64(float64(rate) * float64(ticksPerSecond()) / (1000 * 1000 * 1000))
                if r == 0 {
                        r = 1
                }
@@ -553,8 +556,6 @@ func mutexevent(cycles int64, skip int) {
                cycles = 0
        }
        rate := int64(atomic.Load64(&mutexprofilerate))
-       // TODO(pjw): measure impact of always calling fastrand vs using something
-       // like malloc.go:nextSample()
        if rate > 0 && int64(fastrand())%rate == 0 {
                saveblockevent(cycles, rate, skip+1, mutexProfile)
        }
@@ -791,7 +792,7 @@ func BlockProfile(p []BlockProfileRecord) (n int, ok bool) {
 // If len(p) >= n, MutexProfile copies the profile into p and returns n, true.
 // Otherwise, MutexProfile does not change p, and returns n, false.
 //
-// Most clients should use the runtime/pprof package
+// Most clients should use the [runtime/pprof] package
 // instead of calling MutexProfile directly.
 func MutexProfile(p []BlockProfileRecord) (n int, ok bool) {
        lock(&profBlockLock)
@@ -901,7 +902,7 @@ func goroutineProfileWithLabelsConcurrent(p []StackRecord, labels []unsafe.Point
 
        ourg := getg()
 
-       stopTheWorld("profile")
+       stopTheWorld(stwGoroutineProfile)
        // Using gcount while the world is stopped should give us a consistent view
        // of the number of live goroutines, minus the number of goroutines that are
        // alive and permanently marked as "system". But to make this count agree
@@ -929,6 +930,9 @@ func goroutineProfileWithLabelsConcurrent(p []StackRecord, labels []unsafe.Point
        systemstack(func() {
                saveg(pc, sp, ourg, &p[0])
        })
+       if labels != nil {
+               labels[0] = ourg.labels
+       }
        ourg.goroutineProfiled.Store(goroutineProfileSatisfied)
        goroutineProfile.offset.Store(1)
 
@@ -966,7 +970,7 @@ func goroutineProfileWithLabelsConcurrent(p []StackRecord, labels []unsafe.Point
                tryRecordGoroutineProfile(gp1, Gosched)
        })
 
-       stopTheWorld("profile cleanup")
+       stopTheWorld(stwGoroutineProfileCleanup)
        endOffset := goroutineProfile.offset.Swap(0)
        goroutineProfile.active = false
        goroutineProfile.records = nil
@@ -1101,7 +1105,7 @@ func goroutineProfileWithLabelsSync(p []StackRecord, labels []unsafe.Pointer) (n
                return gp1 != gp && readgstatus(gp1) != _Gdead && !isSystemGoroutine(gp1, false)
        }
 
-       stopTheWorld("profile")
+       stopTheWorld(stwGoroutineProfile)
 
        // World is stopped, no locking required.
        n = 1
@@ -1165,7 +1169,7 @@ func goroutineProfileWithLabelsSync(p []StackRecord, labels []unsafe.Pointer) (n
 // If len(p) >= n, GoroutineProfile copies the profile into p and returns n, true.
 // If len(p) < n, GoroutineProfile does not change p and returns n, false.
 //
-// Most clients should use the runtime/pprof package instead
+// Most clients should use the [runtime/pprof] package instead
 // of calling GoroutineProfile directly.
 func GoroutineProfile(p []StackRecord) (n int, ok bool) {
 
@@ -1187,7 +1191,7 @@ func saveg(pc, sp uintptr, gp *g, r *StackRecord) {
 // into buf after the trace for the current goroutine.
 func Stack(buf []byte, all bool) int {
        if all {
-               stopTheWorld("stack trace")
+               stopTheWorld(stwAllGoroutinesStack)
        }
 
        n := 0