runtime: warn that cputicks() might not be monotonic.
Get rid of gocputicks(), it is no longer used.
LGTM=bradfitz, dave
R=golang-codereviews, bradfitz, dave, minux
CC=golang-codereviews
https://golang.org/cl/161110044
diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s
index b0ed2d8..20d3c47 100644
--- a/src/runtime/asm_386.s
+++ b/src/runtime/asm_386.s
@@ -871,12 +871,6 @@
MOVL DX, ret_hi+4(FP)
RET
-TEXT runtime·gocputicks(SB),NOSPLIT,$0-8
- RDTSC
- MOVL AX, ret_lo+0(FP)
- MOVL DX, ret_hi+4(FP)
- RET
-
TEXT runtime·ldt0setup(SB),NOSPLIT,$16-0
// set up ldt 7 to point at tls0
// ldt 1 would be fine on Linux, but on OS X, 7 is as low as we can go.
diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s
index 2ee3312..7098341 100644
--- a/src/runtime/asm_amd64.s
+++ b/src/runtime/asm_amd64.s
@@ -855,13 +855,6 @@
MOVQ AX, ret+0(FP)
RET
-TEXT runtime·gocputicks(SB),NOSPLIT,$0-8
- RDTSC
- SHLQ $32, DX
- ADDQ DX, AX
- MOVQ AX, ret+0(FP)
- RET
-
// hash function using AES hardware instructions
TEXT runtime·aeshash(SB),NOSPLIT,$0-32
MOVQ p+0(FP), AX // ptr to data
diff --git a/src/runtime/asm_amd64p32.s b/src/runtime/asm_amd64p32.s
index e27f67e..28875bc 100644
--- a/src/runtime/asm_amd64p32.s
+++ b/src/runtime/asm_amd64p32.s
@@ -657,13 +657,6 @@
MOVQ AX, ret+0(FP)
RET
-TEXT runtime·gocputicks(SB),NOSPLIT,$0-8
- RDTSC
- SHLQ $32, DX
- ADDQ DX, AX
- MOVQ AX, ret+0(FP)
- RET
-
// hash function using AES hardware instructions
// For now, our one amd64p32 system (NaCl) does not
// support using AES instructions, so have not bothered to
diff --git a/src/runtime/asm_arm.s b/src/runtime/asm_arm.s
index b214414..621d131 100644
--- a/src/runtime/asm_arm.s
+++ b/src/runtime/asm_arm.s
@@ -1275,9 +1275,6 @@
MOVW R0, ret+0(FP)
RET
-TEXT runtime·gocputicks(SB),NOSPLIT,$0
- B runtime·cputicks(SB)
-
TEXT runtime·return0(SB),NOSPLIT,$0
MOVW $0, R0
RET
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go
index 6561094..3419047 100644
--- a/src/runtime/stubs.go
+++ b/src/runtime/stubs.go
@@ -180,7 +180,11 @@
func breakpoint()
func nanotime() int64
func usleep(usec uint32)
+
+// careful: cputicks is not guaranteed to be monotonic! In particular, we have
+// noticed drift between cpus on certain os/arch combinations. See issue 8976.
func cputicks() int64
+
func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) unsafe.Pointer
func munmap(addr unsafe.Pointer, n uintptr)
func madvise(addr unsafe.Pointer, n uintptr, flags int32)
