diff --git a/src/runtime/mprof.go b/src/runtime/mprof.go
index 006274757e..262f0c5d79 100644
--- a/src/runtime/mprof.go
+++ b/src/runtime/mprof.go
@@ -543,6 +543,19 @@ func saveblockevent(cycles, rate int64, skip int, which bucketType) {
 	gp := getg()
 	mp := acquirem() // we must not be preempted while accessing profstack
 
+	d := dlog()
+	d.s("g=")
+	d.hex(uint64(uintptr(unsafe.Pointer(gp))))
+	d.s("goid=")
+	d.u64(gp.goid)
+	d.s("sched.sp=")
+	d.hex(uint64(gp.sched.sp))
+	d.s("sched.bp=")
+	d.hex(uint64(gp.sched.bp))
+	d.s("curfp=")
+	d.hex(uint64(getfp()))
+	d.end()
+
 	var nstk int
 	if tracefpunwindoff() || gp.m.hasCgoOnStack() {
 		if gp.m.curg == nil || gp.m.curg == gp {
@@ -576,6 +589,7 @@ func saveblockevent(cycles, rate int64, skip int, which bucketType) {
 // inlining, and save remaining frames as "physical" return addresses. The
 // consumer should later use CallersFrames or similar to expand inline frames.
 func fpTracebackPartialExpand(skip int, fp unsafe.Pointer, pcBuf []uintptr) int {
+	gp := getg()
 	var n int
 	lastFuncID := abi.FuncIDNormal
 	skipOrAdd := func(retPC uintptr) bool {
@@ -588,9 +602,24 @@ func fpTracebackPartialExpand(skip int, fp unsafe.Pointer, pcBuf []uintptr) int
 		return n < len(pcBuf)
 	}
 	for n < len(pcBuf) && fp != nil {
+		d := dlog()
+		d.s("goid=")
+		d.u64(gp.goid)
+		d.s("fp=")
+		d.p(fp)
+		d.end()
+		// end now, the next thing might crash
+
 		// return addr sits one word above the frame pointer
 		pc := *(*uintptr)(unsafe.Pointer(uintptr(fp) + goarch.PtrSize))
 
+		d = dlog()
+		d.s("goid=")
+		d.u64(gp.goid)
+		d.s("pc=")
+		d.pc(pc)
+		d.end()
+
 		if skip > 0 {
 			callPC := pc - 1
 			fi := findfunc(callPC)