
In linux 5.14 and hopefully some backports, core scheduling allows processes to be co scheduled within the same domain on SMT enabled systems. The containerd impl sets the core sched domain when launching a shim. This allows a clean way for each shim(container/pod) to be in its own domain and any additional containers, (v2 pods) be be launched with the same domain as well as any exec'd process added to the container. kernel docs: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/core-scheduling.html Signed-off-by: Michael Crosby <michael@thepasture.io>
50 lines
1.4 KiB
Go
50 lines
1.4 KiB
Go
/*
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Copyright The containerd Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package schedcore
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import (
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"golang.org/x/sys/unix"
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)
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// PidType is the type of provided pid value and how it should be treated
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type PidType int
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const (
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// Pid affects the current pid
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Pid PidType = pidtypePid
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// ThreadGroup affects all threads in the group
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ThreadGroup PidType = pidtypeTgid
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// ProcessGroup affects all processes in the group
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ProcessGroup PidType = pidtypePgid
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)
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const (
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pidtypePid = 0
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pidtypeTgid = 1
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pidtypePgid = 2
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)
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// Create a new sched core domain
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func Create(t PidType) error {
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return unix.Prctl(unix.PR_SCHED_CORE, unix.PR_SCHED_CORE_CREATE, 0, uintptr(t), 0)
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}
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// ShareFrom shares the sched core domain from the provided pid
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func ShareFrom(pid uint64, t PidType) error {
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return unix.Prctl(unix.PR_SCHED_CORE, unix.PR_SCHED_CORE_SHARE_FROM, uintptr(pid), uintptr(t), 0)
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}
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