Merge pull request #4310 from egernst/core-sched

shim: add support for core scheduling

src/runtime/pkg/utils/schedcore.go

@@ -0,0 +1,36 @@
+// Copyright (c) 2022 Apple Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package utils
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+// PidType is the type of provided pid value and how it should be treated
+type PidType int
+
+const (
+	pidTypePid            = 0
+	pidTypeThreadGroupId  = 1
+	pidTypeProcessGroupId = 2
+
+	// Pid affects the current pid
+	Pid PidType = pidTypePid
+	// ThreadGroup affects all threads in the group
+	ThreadGroup PidType = pidTypeThreadGroupId
+	// ProcessGroup affects all processes in the group
+	ProcessGroup PidType = pidTypeProcessGroupId
+)
+
+// Create a new sched core domain
+func Create(t PidType) error {
+	return unix.Prctl(unix.PR_SCHED_CORE, unix.PR_SCHED_CORE_CREATE, 0, uintptr(t), 0)
+}
+
+// ShareFrom shares the sched core domain from the provided pid
+func ShareFrom(pid uint64, t PidType) error {
+	return unix.Prctl(unix.PR_SCHED_CORE, unix.PR_SCHED_CORE_SHARE_FROM, uintptr(pid), uintptr(t), 0)
+}