pkg/sysinfo: remove NUMANodeCount

Found a few issues in this code and went ahead to fix them one by one,
only to find out this function is not used anywhere in our codebase
or otherwise (see [1], [2]).

Remove it.

[1]: https://github.com/search?q=org%3Acontainers+NUMANodeCount&type=code
[2]: https://sourcegraph.com/search?q=context%3Aglobal+sysinfo.NUMANodeCount

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

common/pkg/sysinfo/nummem_linux.go

@@ -1,32 +0,0 @@
-//go:build linux
-
-package sysinfo
-
-import (
-	"unsafe"
-
-	"golang.org/x/sys/unix"
-)
-
-// NUMANodeCount queries the system for the count of Memory Nodes available
-// for use to this process.
-func NUMANodeCount() int {
-	// this is the correct flag name (not defined in the unix package)
-	//nolint:revive
-	MPOL_F_MEMS_ALLOWED := (1 << 2)
-	var mask [1024 / 64]uintptr
-	_, _, err := unix.RawSyscall6(unix.SYS_GET_MEMPOLICY, 0, uintptr(unsafe.Pointer(&mask[0])), uintptr(len(mask)*8), 0, uintptr(MPOL_F_MEMS_ALLOWED), 0)
-	if err != 0 {
-		return 0
-	}
-
-	// For every available thread a bit is set in the mask.
-	nmem := 0
-	for _, e := range mask {
-		if e == 0 {
-			continue
-		}
-		nmem += int(popcnt(uint64(e)))
-	}
-	return nmem
-}

common/pkg/sysinfo/nummem_unsupported.go

@@ -1,9 +0,0 @@
-//go:build (windows && ignore) || osx
-
-package sysinfo
-
-// NUMANodeCount queries the system for the count of Memory Nodes available
-// for use to this process. Returns 0 on non NUMAs systems.
-func NUMANodeCount() int {
-	return 0
-}

common/pkg/sysinfo/sysinfo_linux_test.go

@@ -97,13 +97,3 @@ func TestNumCPU(t *testing.T) {
 		t.Fatal("CPU returned must be greater than zero")
 	}
 }
-
-func TestNumMems(t *testing.T) {
-	if _, err := os.Stat("/proc/self/numa_maps"); !errors.Is(err, os.ErrNotExist) {
-		t.Skip("NUMA must be supported")
-	}
-	cpuMems := NUMANodeCount()
-	if cpuMems < 0 {
-		t.Fatal("Invalid number of memory nodes, must be 0 or greater.")
-	}
-}