| // Copyright 2014 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. |
| |
| package runtime |
| |
| func checkgoarm() { |
| // TODO(minux): FP checks like in os_linux_arm.go. |
| |
| // osinit not called yet, so ncpu not set: must use getncpu directly. |
| if getncpu() > 1 && goarm < 7 { |
| print("runtime: this system has multiple CPUs and must use\n") |
| print("atomic synchronization instructions. Recompile using GOARM=7.\n") |
| exit(1) |
| } |
| } |
| |
| //go:nosplit |
| func cputicks() int64 { |
| // Currently cputicks() is used in blocking profiler and to seed runtime·fastrand(). |
| // runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler. |
| // TODO: need more entropy to better seed fastrand. |
| return nanotime() |
| } |