blockProfile
mutexProfile
+ // a profile bucket from one of the categories above whose stack
+ // trace has been fixed up / pruned.
+ prunedProfile
+
// size of bucket hash table
buckHashSize = 179999
}
var (
- mbuckets *bucket // memory profile buckets
- bbuckets *bucket // blocking profile buckets
- xbuckets *bucket // mutex profile buckets
- buckhash *[179999]*bucket
- bucketmem uintptr
+ mbuckets *bucket // memory profile buckets
+ bbuckets *bucket // blocking profile buckets
+ xbuckets *bucket // mutex profile buckets
+ sbuckets *bucket // pre-symbolization profile buckets (stacks fixed up)
+ freebuckets *bucket // freelist of unused fixed up profile buckets
+ buckhash *[179999]*bucket
+ bucketmem uintptr
mProf struct {
// All fields in mProf are protected by proflock.
const mProfCycleWrap = uint32(len(memRecord{}.future)) * (2 << 24)
+// payloadOffset() returns a pointer into the part of a bucket
+// containing the profile payload (skips past the bucket struct itself
+// and then the stack trace).
+func payloadOffset(typ bucketType, nstk uintptr) uintptr {
+ if typ == prunedProfile {
+ // To allow reuse of prunedProfile buckets between different
+ // collections, allocate them with the max stack size (the portion
+ // of the stack used will vary from trace to trace).
+ nstk = maxStack
+ }
+ return unsafe.Sizeof(bucket{}) + uintptr(nstk)*unsafe.Sizeof(uintptr)
+}
+
+func max(x, y uintptr) uintptr {
+ if x > y {
+ return x
+ }
+ return y
+}
+
// 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(location{})
+ size := payloadOffset(typ, uintptr(nstk))
switch typ {
default:
throw("invalid profile bucket type")
+ case prunedProfile:
+ // stack-fixed buckets are large enough to accommodate any payload.
+ size += max(unsafe.Sizeof(memRecord{}), unsafe.Sizeof(blockRecord{}))
case memProfile:
size += unsafe.Sizeof(memRecord{})
case blockProfile, mutexProfile:
}
// stk returns the slice in b holding the stack.
-func (b *bucket) stk() []location {
- stk := (*[maxStack]location)(add(unsafe.Pointer(b), unsafe.Sizeof(*b)))
+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 {
+ if b.typ != memProfile && b.typ != prunedProfile {
throw("bad use of bucket.mp")
}
- data := add(unsafe.Pointer(b), unsafe.Sizeof(*b)+b.nstk*unsafe.Sizeof(location{}))
- return (*memRecord)(data)
+ return (*memRecord)(add(unsafe.Pointer(b), payloadOffset(b.typ, b.nstk)))
}
// bp returns the blockRecord associated with the blockProfile bucket b.
func (b *bucket) bp() *blockRecord {
- if b.typ != blockProfile && b.typ != mutexProfile {
+ if b.typ != blockProfile && b.typ != mutexProfile && b.typ != prunedProfile {
throw("bad use of bucket.bp")
}
- data := add(unsafe.Pointer(b), unsafe.Sizeof(*b)+b.nstk*unsafe.Sizeof(location{}))
- return (*blockRecord)(data)
+ return (*blockRecord)(add(unsafe.Pointer(b), payloadOffset(b.typ, b.nstk)))
}
// Return the bucket for stk[0:nstk], allocating new bucket if needed.
-func stkbucket(typ bucketType, size uintptr, stk []location, alloc bool) *bucket {
+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 {
// Hash stack.
var h uintptr
- for _, loc := range stk {
- h += loc.pc
+ for _, pc := range stk {
+ h += pc
h += h << 10
h ^= h >> 6
}
} else if typ == mutexProfile {
b.allnext = xbuckets
xbuckets = b
+ } else if typ == prunedProfile {
+ b.allnext = sbuckets
+ sbuckets = b
} else {
b.allnext = bbuckets
bbuckets = b
return b
}
-func eqslice(x, y []location) bool {
+func eqslice(x, y []uintptr) bool {
if len(x) != len(y) {
return false
}
// Called by malloc to record a profiled block.
func mProf_Malloc(p unsafe.Pointer, size uintptr) {
- var stk [maxStack]location
- nstk := callers(4, stk[:])
+ var stk [maxStack]uintptr
+ nstk := callersRaw(1, stk[:])
lock(&proflock)
b := stkbucket(memProfile, size, stk[:nstk], true)
c := mProf.cycle
func saveblockevent(cycles int64, skip int, which bucketType) {
gp := getg()
var nstk int
- var stk [maxStack]location
+ var stk [maxStack]uintptr
if gp.m.curg == nil || gp.m.curg == gp {
- nstk = callers(skip, stk[:])
+ nstk = callersRaw(skip, stk[:])
} else {
// FIXME: This should get a traceback of gp.m.curg.
// nstk = gcallers(gp.m.curg, skip, stk[:])
- nstk = callers(skip, stk[:])
+ nstk = callersRaw(skip, stk[:])
}
lock(&proflock)
b := stkbucket(which, 0, stk[:nstk], true)
return r.Stack0[0:]
}
+// reusebucket tries to pick a prunedProfile bucket off
+// the freebuckets list, returning it if one is available or nil
+// if the free list is empty.
+func reusebucket(nstk int) *bucket {
+ var b *bucket
+ if freebuckets != nil {
+ b = freebuckets
+ freebuckets = freebuckets.allnext
+ b.typ = prunedProfile
+ b.nstk = uintptr(nstk)
+ mp := b.mp()
+ // Hack: rely on the fact that memprofile records are
+ // larger than blockprofile records when clearing.
+ *mp = memRecord{}
+ }
+ return b
+}
+
+// freebucket appends the specified prunedProfile bucket
+// onto the free list, and removes references to it from the hash.
+func freebucket(tofree *bucket) *bucket {
+ // Thread this bucket into the free list.
+ ret := tofree.allnext
+ tofree.allnext = freebuckets
+ freebuckets = tofree
+
+ // Clean up the hash. The hash may point directly to this bucket...
+ i := int(tofree.hash % buckHashSize)
+ if buckhash[i] == tofree {
+ buckhash[i] = tofree.next
+ } else {
+ // ... or when this bucket was inserted by stkbucket, it may have been
+ // chained off some other unrelated bucket.
+ for b := buckhash[i]; b != nil; b = b.next {
+ if b.next == tofree {
+ b.next = tofree.next
+ break
+ }
+ }
+ }
+ return ret
+}
+
+// fixupStack takes a 'raw' stack trace (stack of PCs generated by
+// callersRaw) and performs pre-symbolization fixup on it, returning
+// the results in 'canonStack'. For each frame we look at the
+// file/func/line information, then use that info to decide whether to
+// include the frame in the final symbolized stack (removing frames
+// corresponding to 'morestack' routines, for example). We also expand
+// frames if the PC values to which they refer correponds to inlined
+// functions to allow for expanded symbolic info to be filled in
+// later. Note: there is code in go-callers.c's backtrace_full callback()
+// function that performs very similar fixups; these two code paths
+// should be kept in sync.
+func fixupStack(stk []uintptr, canonStack *[maxStack]uintptr, size uintptr) int {
+ var cidx int
+ var termTrace bool
+ for _, pc := range stk {
+ // Subtract 1 from PC to undo the 1 we added in callback in
+ // go-callers.c.
+ function, file, _, frames := funcfileline(pc-1, -1)
+
+ // Skip split-stack functions (match by function name)
+ skipFrame := false
+ if hasPrefix(function, "_____morestack_") || hasPrefix(function, "__morestack_") {
+ skipFrame = true
+ }
+
+ // Skip split-stack functions (match by file)
+ if hasSuffix(file, "/morestack.S") {
+ skipFrame = true
+ }
+
+ // Skip thunks and recover functions. There is no equivalent to
+ // these functions in the gc toolchain.
+ fcn := function
+ if hasSuffix(fcn, "..r") {
+ skipFrame = true
+ } else {
+ for fcn != "" && (fcn[len(fcn)-1] >= '0' && fcn[len(fcn)-1] <= '9') {
+ fcn = fcn[:len(fcn)-1]
+ }
+ if hasSuffix(fcn, "..stub") || hasSuffix(fcn, "..thunk") {
+ skipFrame = true
+ }
+ }
+ if skipFrame {
+ continue
+ }
+
+ // Terminate the trace if we encounter a frame corresponding to
+ // runtime.main, runtime.kickoff, makecontext, etc. See the
+ // corresponding code in go-callers.c, callback function used
+ // with backtrace_full.
+ if function == "makecontext" {
+ termTrace = true
+ }
+ if hasSuffix(file, "/proc.c") && function == "runtime_mstart" {
+ termTrace = true
+ }
+ if hasSuffix(file, "/proc.go") &&
+ (function == "runtime.main" || function == "runtime.kickoff") {
+ termTrace = true
+ }
+
+ // Expand inline frames.
+ for i := 0; i < frames; i++ {
+ (*canonStack)[cidx] = pc
+ cidx++
+ if cidx >= maxStack {
+ termTrace = true
+ break
+ }
+ }
+ if termTrace {
+ break
+ }
+ }
+ return cidx
+}
+
+// fixupBucket takes a raw memprofile bucket and creates a new bucket
+// in which the stack trace has been fixed up (inline frames expanded,
+// unwanted frames stripped out). Original bucket is left unmodified;
+// a new symbolizeProfile bucket may be generated as a side effect.
+// Payload information from the original bucket is incorporated into
+// the new bucket.
+func fixupBucket(b *bucket) {
+ var canonStack [maxStack]uintptr
+ frames := fixupStack(b.stk(), &canonStack, b.size)
+ cb := stkbucket(prunedProfile, b.size, canonStack[:frames], true)
+ switch b.typ {
+ default:
+ throw("invalid profile bucket type")
+ case memProfile:
+ rawrecord := b.mp()
+ cb.mp().active.add(&rawrecord.active)
+ case blockProfile, mutexProfile:
+ bpcount := b.bp().count
+ cb.bp().count += bpcount
+ cb.bp().cycles += bpcount
+ }
+}
+
// MemProfile returns a profile of memory allocated and freed per allocation
// site.
//
}
}
if n <= len(p) {
- ok = true
- idx := 0
- for b := mbuckets; b != nil; b = b.allnext {
+ var bnext *bucket
+
+ // Post-process raw buckets to fix up their stack traces
+ for b := mbuckets; b != nil; b = bnext {
+ bnext = b.allnext
mp := b.mp()
if inuseZero || mp.active.alloc_bytes != mp.active.free_bytes {
- record(&p[idx], b)
- idx++
+ fixupBucket(b)
}
}
+
+ // Record pruned/fixed-up buckets
+ ok = true
+ idx := 0
+ for b := sbuckets; b != nil; b = b.allnext {
+ record(&p[idx], b)
+ idx++
+ }
+ n = idx
+
+ // Free up pruned buckets for use in next round
+ for b := sbuckets; b != nil; b = bnext {
+ bnext = freebucket(b)
+ }
+ sbuckets = nil
}
unlock(&proflock)
return
r.FreeBytes = int64(mp.active.free_bytes)
r.AllocObjects = int64(mp.active.allocs)
r.FreeObjects = int64(mp.active.frees)
- for i, loc := range b.stk() {
+ for i, pc := range b.stk() {
if i >= len(r.Stack0) {
break
}
- r.Stack0[i] = loc.pc
+ r.Stack0[i] = pc
}
for i := int(b.nstk); i < len(r.Stack0); i++ {
r.Stack0[i] = 0
}
}
-func iterate_memprof(fn func(*bucket, uintptr, *location, uintptr, uintptr, uintptr)) {
+func iterate_memprof(fn func(*bucket, uintptr, *uintptr, uintptr, uintptr, uintptr)) {
lock(&proflock)
for b := mbuckets; b != nil; b = b.allnext {
mp := b.mp()
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 {
+func harvestBlockMutexProfile(buckets *bucket, p []BlockProfileRecord) (n int, ok bool) {
+ for b := buckets; b != nil; b = b.allnext {
n++
}
if n <= len(p) {
+ var bnext *bucket
+
+ // Post-process raw buckets to create pruned/fixed-up buckets
+ for b := buckets; b != nil; b = bnext {
+ bnext = b.allnext
+ fixupBucket(b)
+ }
+
+ // Record
ok = true
- for b := bbuckets; b != nil; b = b.allnext {
+ for b := sbuckets; b != nil; b = b.allnext {
bp := b.bp()
r := &p[0]
r.Count = bp.count
r.Cycles = bp.cycles
i := 0
- var loc location
- for i, loc = range b.stk() {
+ var pc uintptr
+ for i, pc = range b.stk() {
if i >= len(r.Stack0) {
break
}
- r.Stack0[i] = loc.pc
+ r.Stack0[i] = pc
}
for ; i < len(r.Stack0); i++ {
r.Stack0[i] = 0
}
p = p[1:]
}
+
+ // Free up pruned buckets for use in next round.
+ for b := sbuckets; b != nil; b = bnext {
+ bnext = freebucket(b)
+ }
+ sbuckets = nil
}
+ return
+}
+
+// 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)
+ n, ok = harvestBlockMutexProfile(bbuckets, p)
unlock(&proflock)
return
}
// instead of calling MutexProfile directly.
func MutexProfile(p []BlockProfileRecord) (n int, ok bool) {
lock(&proflock)
- for b := xbuckets; b != nil; b = b.allnext {
- n++
- }
- if n <= len(p) {
- ok = true
- for b := xbuckets; b != nil; b = b.allnext {
- bp := b.bp()
- r := &p[0]
- r.Count = int64(bp.count)
- r.Cycles = bp.cycles
- i := 0
- var loc location
- for i, loc = range b.stk() {
- if i >= len(r.Stack0) {
- break
- }
- r.Stack0[i] = loc.pc
- }
- for ; i < len(r.Stack0); i++ {
- r.Stack0[i] = 0
- }
- p = p[1:]
- }
- }
+ n, ok = harvestBlockMutexProfile(xbuckets, p)
unlock(&proflock)
return
}
projects / gcc.git / commitdiff