Files
podman/pkg/sysinfo/numcpu_linux.go
Daniel J Walsh 43686072d3 Update vendor of runc
Updating the vendor or runc to pull in some fixes that we need.
In order to get this vendor to work, we needed to update the vendor
of docker/docker, which causes all sorts of issues, just to fix
the docker/pkg/sysinfo.  Rather then doing this, I pulled in pkg/sysinfo
into libpod and fixed the code locally.

I then switched the use of docker/pkg/sysinfo to libpod/pkg/sysinfo.

I also switched out the docker/pkg/mount to containers/storage/pkg/mount

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
2019-01-04 14:54:59 -05:00

45 lines
943 B
Go

// +build linux
package sysinfo
import (
"runtime"
"unsafe"
"golang.org/x/sys/unix"
)
// numCPU queries the system for the count of threads available
// for use to this process.
//
// Issues two syscalls.
// Returns 0 on errors. Use |runtime.NumCPU| in that case.
func numCPU() int {
// Gets the affinity mask for a process: The very one invoking this function.
pid, _, _ := unix.RawSyscall(unix.SYS_GETPID, 0, 0, 0)
var mask [1024 / 64]uintptr
_, _, err := unix.RawSyscall(unix.SYS_SCHED_GETAFFINITY, pid, uintptr(len(mask)*8), uintptr(unsafe.Pointer(&mask[0])))
if err != 0 {
return 0
}
// For every available thread a bit is set in the mask.
ncpu := 0
for _, e := range mask {
if e == 0 {
continue
}
ncpu += int(popcnt(uint64(e)))
}
return ncpu
}
// NumCPU returns the number of CPUs which are currently online
func NumCPU() int {
if ncpu := numCPU(); ncpu > 0 {
return ncpu
}
return runtime.NumCPU()
}