cybercyst/go
1
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-05-30 19:52:53 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

runtime: use hw.ncpuonline sysctl in getncpu on netbsd

Browse Source 
Since NetBSD 7, hw.ncpuonline reports the number of CPUs online, while
hw.cpu reports the number of CPUs configured. Try hw.cpuonline first and
fall back to hw.ncpu in case it fails (which is the case on NetBSD
before 7.0).

This follows the behavior on OpenBSD (see CL 161757). Also, Go
in pkgsrc is patched to use hw.cpuonline, so this CL would allow said
patch to be dropped.

Updates #30824

Change-Id: Id1c19dff2c1e4401e6074179fae7c708ba0e3098
Reviewed-on: https://go-review.googlesource.com/c/go/+/231957
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
This commit is contained in:
Tobias Klauser 2020-05-04 18:36:31 +02:00 committed by Tobias Klauser
parent 9138a2a67f
commit d79350bac7
1 changed files with 19 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/runtime/os_netbsd.go
View File

@ -95,18 +95,28 @@ var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)
// From NetBSD's <sys/sysctl.h>
const (
_CTL_HW = 6
_HW_NCPU = 3
_HW_PAGESIZE = 7
_CTL_HW = 6
_HW_NCPU = 3
_HW_PAGESIZE = 7
_HW_NCPUONLINE = 16
)
func getncpu() int32 {
mib := [2]uint32{_CTL_HW, _HW_NCPU}
out := uint32(0)
func sysctlInt(mib []uint32) (int32, bool) {
var out int32
nout := unsafe.Sizeof(out)
ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
if ret >= 0 {
return int32(out)
ret := sysctl(&mib[0], uint32(len(mib)), (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
if ret < 0 {
return 0, false
}
return out, true
}
func getncpu() int32 {
if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPUONLINE}); ok {
return int32(n)
}
if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPU}); ok {
return int32(n)
}
return 1
}