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-rw-r--r--src/runtime/mprof.go672
1 files changed, 672 insertions, 0 deletions
diff --git a/src/runtime/mprof.go b/src/runtime/mprof.go
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+++ b/src/runtime/mprof.go
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+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Malloc profiling.
+// Patterned after tcmalloc's algorithms; shorter code.
+
+package runtime
+
+import (
+ "unsafe"
+)
+
+// NOTE(rsc): Everything here could use cas if contention became an issue.
+var proflock mutex
+
+// All memory allocations are local and do not escape outside of the profiler.
+// The profiler is forbidden from referring to garbage-collected memory.
+
+const (
+ // profile types
+ memProfile bucketType = 1 + iota
+ blockProfile
+
+ // size of bucket hash table
+ buckHashSize = 179999
+
+ // max depth of stack to record in bucket
+ maxStack = 32
+)
+
+type bucketType int
+
+// A bucket holds per-call-stack profiling information.
+// The representation is a bit sleazy, inherited from C.
+// This struct defines the bucket header. It is followed in
+// memory by the stack words and then the actual record
+// data, either a memRecord or a blockRecord.
+//
+// Per-call-stack profiling information.
+// Lookup by hashing call stack into a linked-list hash table.
+type bucket struct {
+ next *bucket
+ allnext *bucket
+ typ bucketType // memBucket or blockBucket
+ hash uintptr
+ size uintptr
+ nstk uintptr
+}
+
+// A memRecord is the bucket data for a bucket of type memProfile,
+// part of the memory profile.
+type memRecord struct {
+ // The following complex 3-stage scheme of stats accumulation
+ // is required to obtain a consistent picture of mallocs and frees
+ // for some point in time.
+ // The problem is that mallocs come in real time, while frees
+ // come only after a GC during concurrent sweeping. So if we would
+ // naively count them, we would get a skew toward mallocs.
+ //
+ // Mallocs are accounted in recent stats.
+ // Explicit frees are accounted in recent stats.
+ // GC frees are accounted in prev stats.
+ // After GC prev stats are added to final stats and
+ // recent stats are moved into prev stats.
+ allocs uintptr
+ frees uintptr
+ alloc_bytes uintptr
+ free_bytes uintptr
+
+ // changes between next-to-last GC and last GC
+ prev_allocs uintptr
+ prev_frees uintptr
+ prev_alloc_bytes uintptr
+ prev_free_bytes uintptr
+
+ // changes since last GC
+ recent_allocs uintptr
+ recent_frees uintptr
+ recent_alloc_bytes uintptr
+ recent_free_bytes uintptr
+}
+
+// A blockRecord is the bucket data for a bucket of type blockProfile,
+// part of the blocking profile.
+type blockRecord struct {
+ count int64
+ cycles int64
+}
+
+var (
+ mbuckets *bucket // memory profile buckets
+ bbuckets *bucket // blocking profile buckets
+ buckhash *[179999]*bucket
+ bucketmem uintptr
+)
+
+// newBucket allocates a bucket with the given type and number of stack entries.
+func newBucket(typ bucketType, nstk int) *bucket {
+ size := unsafe.Sizeof(bucket{}) + uintptr(nstk)*unsafe.Sizeof(uintptr(0))
+ switch typ {
+ default:
+ gothrow("invalid profile bucket type")
+ case memProfile:
+ size += unsafe.Sizeof(memRecord{})
+ case blockProfile:
+ size += unsafe.Sizeof(blockRecord{})
+ }
+
+ b := (*bucket)(persistentalloc(size, 0, &memstats.buckhash_sys))
+ bucketmem += size
+ b.typ = typ
+ b.nstk = uintptr(nstk)
+ return b
+}
+
+// stk returns the slice in b holding the stack.
+func (b *bucket) stk() []uintptr {
+ stk := (*[maxStack]uintptr)(add(unsafe.Pointer(b), unsafe.Sizeof(*b)))
+ return stk[:b.nstk:b.nstk]
+}
+
+// mp returns the memRecord associated with the memProfile bucket b.
+func (b *bucket) mp() *memRecord {
+ if b.typ != memProfile {
+ gothrow("bad use of bucket.mp")
+ }
+ data := add(unsafe.Pointer(b), unsafe.Sizeof(*b)+b.nstk*unsafe.Sizeof(uintptr(0)))
+ return (*memRecord)(data)
+}
+
+// bp returns the blockRecord associated with the blockProfile bucket b.
+func (b *bucket) bp() *blockRecord {
+ if b.typ != blockProfile {
+ gothrow("bad use of bucket.bp")
+ }
+ data := add(unsafe.Pointer(b), unsafe.Sizeof(*b)+b.nstk*unsafe.Sizeof(uintptr(0)))
+ return (*blockRecord)(data)
+}
+
+// Return the bucket for stk[0:nstk], allocating new bucket if needed.
+func stkbucket(typ bucketType, size uintptr, stk []uintptr, alloc bool) *bucket {
+ if buckhash == nil {
+ buckhash = (*[buckHashSize]*bucket)(sysAlloc(unsafe.Sizeof(*buckhash), &memstats.buckhash_sys))
+ if buckhash == nil {
+ gothrow("runtime: cannot allocate memory")
+ }
+ }
+
+ // Hash stack.
+ var h uintptr
+ for _, pc := range stk {
+ h += pc
+ h += h << 10
+ h ^= h >> 6
+ }
+ // hash in size
+ h += size
+ h += h << 10
+ h ^= h >> 6
+ // finalize
+ h += h << 3
+ h ^= h >> 11
+
+ i := int(h % buckHashSize)
+ for b := buckhash[i]; b != nil; b = b.next {
+ if b.typ == typ && b.hash == h && b.size == size && eqslice(b.stk(), stk) {
+ return b
+ }
+ }
+
+ if !alloc {
+ return nil
+ }
+
+ // Create new bucket.
+ b := newBucket(typ, len(stk))
+ copy(b.stk(), stk)
+ b.hash = h
+ b.size = size
+ b.next = buckhash[i]
+ buckhash[i] = b
+ if typ == memProfile {
+ b.allnext = mbuckets
+ mbuckets = b
+ } else {
+ b.allnext = bbuckets
+ bbuckets = b
+ }
+ return b
+}
+
+func sysAlloc(n uintptr, stat *uint64) unsafe.Pointer
+
+func eqslice(x, y []uintptr) bool {
+ if len(x) != len(y) {
+ return false
+ }
+ for i, xi := range x {
+ if xi != y[i] {
+ return false
+ }
+ }
+ return true
+}
+
+func mprof_GC() {
+ for b := mbuckets; b != nil; b = b.allnext {
+ mp := b.mp()
+ mp.allocs += mp.prev_allocs
+ mp.frees += mp.prev_frees
+ mp.alloc_bytes += mp.prev_alloc_bytes
+ mp.free_bytes += mp.prev_free_bytes
+
+ mp.prev_allocs = mp.recent_allocs
+ mp.prev_frees = mp.recent_frees
+ mp.prev_alloc_bytes = mp.recent_alloc_bytes
+ mp.prev_free_bytes = mp.recent_free_bytes
+
+ mp.recent_allocs = 0
+ mp.recent_frees = 0
+ mp.recent_alloc_bytes = 0
+ mp.recent_free_bytes = 0
+ }
+}
+
+// Record that a gc just happened: all the 'recent' statistics are now real.
+func mProf_GC() {
+ lock(&proflock)
+ mprof_GC()
+ unlock(&proflock)
+}
+
+// Called by malloc to record a profiled block.
+func mProf_Malloc(p unsafe.Pointer, size uintptr) {
+ var stk [maxStack]uintptr
+ nstk := callers(4, &stk[0], len(stk))
+ lock(&proflock)
+ b := stkbucket(memProfile, size, stk[:nstk], true)
+ mp := b.mp()
+ mp.recent_allocs++
+ mp.recent_alloc_bytes += size
+ unlock(&proflock)
+
+ // Setprofilebucket locks a bunch of other mutexes, so we call it outside of proflock.
+ // This reduces potential contention and chances of deadlocks.
+ // Since the object must be alive during call to mProf_Malloc,
+ // it's fine to do this non-atomically.
+ setprofilebucket(p, b)
+}
+
+func setprofilebucket_m() // mheap.c
+
+func setprofilebucket(p unsafe.Pointer, b *bucket) {
+ g := getg()
+ g.m.ptrarg[0] = p
+ g.m.ptrarg[1] = unsafe.Pointer(b)
+ onM(setprofilebucket_m)
+}
+
+// Called when freeing a profiled block.
+func mProf_Free(b *bucket, size uintptr, freed bool) {
+ lock(&proflock)
+ mp := b.mp()
+ if freed {
+ mp.recent_frees++
+ mp.recent_free_bytes += size
+ } else {
+ mp.prev_frees++
+ mp.prev_free_bytes += size
+ }
+ unlock(&proflock)
+}
+
+var blockprofilerate uint64 // in CPU ticks
+
+// SetBlockProfileRate controls the fraction of goroutine blocking events
+// that are reported in the blocking profile. The profiler aims to sample
+// an average of one blocking event per rate nanoseconds spent blocked.
+//
+// To include every blocking event in the profile, pass rate = 1.
+// To turn off profiling entirely, pass rate <= 0.
+func SetBlockProfileRate(rate int) {
+ var r int64
+ if rate <= 0 {
+ r = 0 // disable profiling
+ } else if rate == 1 {
+ 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))
+ if r == 0 {
+ r = 1
+ }
+ }
+
+ atomicstore64(&blockprofilerate, uint64(r))
+}
+
+func blockevent(cycles int64, skip int) {
+ if cycles <= 0 {
+ cycles = 1
+ }
+ rate := int64(atomicload64(&blockprofilerate))
+ if rate <= 0 || (rate > cycles && int64(fastrand1())%rate > cycles) {
+ return
+ }
+ gp := getg()
+ var nstk int
+ var stk [maxStack]uintptr
+ if gp.m.curg == nil || gp.m.curg == gp {
+ nstk = callers(skip, &stk[0], len(stk))
+ } else {
+ nstk = gcallers(gp.m.curg, skip, &stk[0], len(stk))
+ }
+ lock(&proflock)
+ b := stkbucket(blockProfile, 0, stk[:nstk], true)
+ b.bp().count++
+ b.bp().cycles += cycles
+ unlock(&proflock)
+}
+
+// Go interface to profile data.
+
+// A StackRecord describes a single execution stack.
+type StackRecord struct {
+ Stack0 [32]uintptr // stack trace for this record; ends at first 0 entry
+}
+
+// Stack returns the stack trace associated with the record,
+// a prefix of r.Stack0.
+func (r *StackRecord) Stack() []uintptr {
+ for i, v := range r.Stack0 {
+ if v == 0 {
+ return r.Stack0[0:i]
+ }
+ }
+ return r.Stack0[0:]
+}
+
+// MemProfileRate controls the fraction of memory allocations
+// that are recorded and reported in the memory profile.
+// The profiler aims to sample an average of
+// one allocation per MemProfileRate bytes allocated.
+//
+// To include every allocated block in the profile, set MemProfileRate to 1.
+// To turn off profiling entirely, set MemProfileRate to 0.
+//
+// The tools that process the memory profiles assume that the
+// profile rate is constant across the lifetime of the program
+// and equal to the current value. Programs that change the
+// memory profiling rate should do so just once, as early as
+// possible in the execution of the program (for example,
+// at the beginning of main).
+var MemProfileRate int = 512 * 1024
+
+// A MemProfileRecord describes the live objects allocated
+// by a particular call sequence (stack trace).
+type MemProfileRecord struct {
+ AllocBytes, FreeBytes int64 // number of bytes allocated, freed
+ AllocObjects, FreeObjects int64 // number of objects allocated, freed
+ Stack0 [32]uintptr // stack trace for this record; ends at first 0 entry
+}
+
+// InUseBytes returns the number of bytes in use (AllocBytes - FreeBytes).
+func (r *MemProfileRecord) InUseBytes() int64 { return r.AllocBytes - r.FreeBytes }
+
+// InUseObjects returns the number of objects in use (AllocObjects - FreeObjects).
+func (r *MemProfileRecord) InUseObjects() int64 {
+ return r.AllocObjects - r.FreeObjects
+}
+
+// Stack returns the stack trace associated with the record,
+// a prefix of r.Stack0.
+func (r *MemProfileRecord) Stack() []uintptr {
+ for i, v := range r.Stack0 {
+ if v == 0 {
+ return r.Stack0[0:i]
+ }
+ }
+ return r.Stack0[0:]
+}
+
+// MemProfile returns n, the number of records in the current memory profile.
+// If len(p) >= n, MemProfile copies the profile into p and returns n, true.
+// If len(p) < n, MemProfile does not change p and returns n, false.
+//
+// If inuseZero is true, the profile includes allocation records
+// where r.AllocBytes > 0 but r.AllocBytes == r.FreeBytes.
+// These are sites where memory was allocated, but it has all
+// been released back to the runtime.
+//
+// Most clients should use the runtime/pprof package or
+// the testing package's -test.memprofile flag instead
+// of calling MemProfile directly.
+func MemProfile(p []MemProfileRecord, inuseZero bool) (n int, ok bool) {
+ lock(&proflock)
+ clear := true
+ for b := mbuckets; b != nil; b = b.allnext {
+ mp := b.mp()
+ if inuseZero || mp.alloc_bytes != mp.free_bytes {
+ n++
+ }
+ if mp.allocs != 0 || mp.frees != 0 {
+ clear = false
+ }
+ }
+ if clear {
+ // Absolutely no data, suggesting that a garbage collection
+ // has not yet happened. In order to allow profiling when
+ // garbage collection is disabled from the beginning of execution,
+ // accumulate stats as if a GC just happened, and recount buckets.
+ mprof_GC()
+ mprof_GC()
+ n = 0
+ for b := mbuckets; b != nil; b = b.allnext {
+ mp := b.mp()
+ if inuseZero || mp.alloc_bytes != mp.free_bytes {
+ n++
+ }
+ }
+ }
+ if n <= len(p) {
+ ok = true
+ idx := 0
+ for b := mbuckets; b != nil; b = b.allnext {
+ mp := b.mp()
+ if inuseZero || mp.alloc_bytes != mp.free_bytes {
+ record(&p[idx], b)
+ idx++
+ }
+ }
+ }
+ unlock(&proflock)
+ return
+}
+
+// Write b's data to r.
+func record(r *MemProfileRecord, b *bucket) {
+ mp := b.mp()
+ r.AllocBytes = int64(mp.alloc_bytes)
+ r.FreeBytes = int64(mp.free_bytes)
+ r.AllocObjects = int64(mp.allocs)
+ r.FreeObjects = int64(mp.frees)
+ copy(r.Stack0[:], b.stk())
+ for i := int(b.nstk); i < len(r.Stack0); i++ {
+ r.Stack0[i] = 0
+ }
+}
+
+func iterate_memprof(fn func(*bucket, uintptr, *uintptr, uintptr, uintptr, uintptr)) {
+ lock(&proflock)
+ for b := mbuckets; b != nil; b = b.allnext {
+ mp := b.mp()
+ fn(b, uintptr(b.nstk), &b.stk()[0], b.size, mp.allocs, mp.frees)
+ }
+ unlock(&proflock)
+}
+
+// BlockProfileRecord describes blocking events originated
+// at a particular call sequence (stack trace).
+type BlockProfileRecord struct {
+ Count int64
+ Cycles int64
+ StackRecord
+}
+
+// BlockProfile returns n, the number of records in the current blocking profile.
+// If len(p) >= n, BlockProfile copies the profile into p and returns n, true.
+// If len(p) < n, BlockProfile does not change p and returns n, false.
+//
+// Most clients should use the runtime/pprof package or
+// the testing package's -test.blockprofile flag instead
+// of calling BlockProfile directly.
+func BlockProfile(p []BlockProfileRecord) (n int, ok bool) {
+ lock(&proflock)
+ for b := bbuckets; b != nil; b = b.allnext {
+ n++
+ }
+ if n <= len(p) {
+ ok = true
+ for b := bbuckets; b != nil; b = b.allnext {
+ bp := b.bp()
+ r := &p[0]
+ r.Count = int64(bp.count)
+ r.Cycles = int64(bp.cycles)
+ i := copy(r.Stack0[:], b.stk())
+ for ; i < len(r.Stack0); i++ {
+ r.Stack0[i] = 0
+ }
+ p = p[1:]
+ }
+ }
+ unlock(&proflock)
+ return
+}
+
+// ThreadCreateProfile returns n, the number of records in the thread creation profile.
+// If len(p) >= n, ThreadCreateProfile copies the profile into p and returns n, true.
+// If len(p) < n, ThreadCreateProfile does not change p and returns n, false.
+//
+// Most clients should use the runtime/pprof package instead
+// of calling ThreadCreateProfile directly.
+func ThreadCreateProfile(p []StackRecord) (n int, ok bool) {
+ first := (*m)(atomicloadp(unsafe.Pointer(&allm)))
+ for mp := first; mp != nil; mp = mp.alllink {
+ n++
+ }
+ if n <= len(p) {
+ ok = true
+ i := 0
+ for mp := first; mp != nil; mp = mp.alllink {
+ for s := range mp.createstack {
+ p[i].Stack0[s] = uintptr(mp.createstack[s])
+ }
+ i++
+ }
+ }
+ return
+}
+
+var allgs []*g // proc.c
+
+// GoroutineProfile returns n, the number of records in the active goroutine stack profile.
+// 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
+// of calling GoroutineProfile directly.
+func GoroutineProfile(p []StackRecord) (n int, ok bool) {
+
+ n = NumGoroutine()
+ if n <= len(p) {
+ gp := getg()
+ semacquire(&worldsema, false)
+ gp.m.gcing = 1
+ onM(stoptheworld)
+
+ n = NumGoroutine()
+ if n <= len(p) {
+ ok = true
+ r := p
+ sp := getcallersp(unsafe.Pointer(&p))
+ pc := getcallerpc(unsafe.Pointer(&p))
+ onM(func() {
+ saveg(pc, sp, gp, &r[0])
+ })
+ r = r[1:]
+ for _, gp1 := range allgs {
+ if gp1 == gp || readgstatus(gp1) == _Gdead {
+ continue
+ }
+ saveg(^uintptr(0), ^uintptr(0), gp1, &r[0])
+ r = r[1:]
+ }
+ }
+
+ gp.m.gcing = 0
+ semrelease(&worldsema)
+ onM(starttheworld)
+ }
+
+ return n, ok
+}
+
+func saveg(pc, sp uintptr, gp *g, r *StackRecord) {
+ n := gentraceback(pc, sp, 0, gp, 0, &r.Stack0[0], len(r.Stack0), nil, nil, 0)
+ if n < len(r.Stack0) {
+ r.Stack0[n] = 0
+ }
+}
+
+// Stack formats a stack trace of the calling goroutine into buf
+// and returns the number of bytes written to buf.
+// If all is true, Stack formats stack traces of all other goroutines
+// into buf after the trace for the current goroutine.
+func Stack(buf []byte, all bool) int {
+ mp := acquirem()
+ gp := mp.curg
+ if all {
+ semacquire(&worldsema, false)
+ mp.gcing = 1
+ releasem(mp)
+ onM(stoptheworld)
+ if mp != acquirem() {
+ gothrow("Stack: rescheduled")
+ }
+ }
+
+ n := 0
+ if len(buf) > 0 {
+ sp := getcallersp(unsafe.Pointer(&buf))
+ pc := getcallerpc(unsafe.Pointer(&buf))
+ onM(func() {
+ g0 := getg()
+ g0.writebuf = buf[0:0:len(buf)]
+ goroutineheader(gp)
+ traceback(pc, sp, 0, gp)
+ if all {
+ tracebackothers(gp)
+ }
+ n = len(g0.writebuf)
+ g0.writebuf = nil
+ })
+ }
+
+ if all {
+ mp.gcing = 0
+ semrelease(&worldsema)
+ onM(starttheworld)
+ }
+ releasem(mp)
+ return n
+}
+
+// Tracing of alloc/free/gc.
+
+var tracelock mutex
+
+func tracealloc(p unsafe.Pointer, size uintptr, typ *_type) {
+ lock(&tracelock)
+ gp := getg()
+ gp.m.traceback = 2
+ if typ == nil {
+ print("tracealloc(", p, ", ", hex(size), ")\n")
+ } else {
+ print("tracealloc(", p, ", ", hex(size), ", ", *typ._string, ")\n")
+ }
+ if gp.m.curg == nil || gp == gp.m.curg {
+ goroutineheader(gp)
+ pc := getcallerpc(unsafe.Pointer(&p))
+ sp := getcallersp(unsafe.Pointer(&p))
+ onM(func() {
+ traceback(pc, sp, 0, gp)
+ })
+ } else {
+ goroutineheader(gp.m.curg)
+ traceback(^uintptr(0), ^uintptr(0), 0, gp.m.curg)
+ }
+ print("\n")
+ gp.m.traceback = 0
+ unlock(&tracelock)
+}
+
+func tracefree(p unsafe.Pointer, size uintptr) {
+ lock(&tracelock)
+ gp := getg()
+ gp.m.traceback = 2
+ print("tracefree(", p, ", ", hex(size), ")\n")
+ goroutineheader(gp)
+ pc := getcallerpc(unsafe.Pointer(&p))
+ sp := getcallersp(unsafe.Pointer(&p))
+ onM(func() {
+ traceback(pc, sp, 0, gp)
+ })
+ print("\n")
+ gp.m.traceback = 0
+ unlock(&tracelock)
+}
+
+func tracegc() {
+ lock(&tracelock)
+ gp := getg()
+ gp.m.traceback = 2
+ print("tracegc()\n")
+ // running on m->g0 stack; show all non-g0 goroutines
+ tracebackothers(gp)
+ print("end tracegc\n")
+ print("\n")
+ gp.m.traceback = 0
+ unlock(&tracelock)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-19 16:03:00 +0000