17244: Use crunch-run's cgroup, not init's, for "host" stats.

[arvados.git] / lib / crunchrun / crunchrun.go

diff --git a/lib/crunchrun/crunchrun.go b/lib/crunchrun/crunchrun.go
index 04fc6c0d0c88a10935c28f19d09cc7410432d9dd..9add35335f39380ca61f78390f0eae1ce7ebda03 100644 (file)
--- a/lib/crunchrun/crunchrun.go
+++ b/lib/crunchrun/crunchrun.go
@@ -742,8 +742,16 @@ func (runner *ContainerRunner) startHoststat() error {
        }
        runner.hoststatLogger = NewThrottledLogger(w)
        runner.hoststatReporter = &crunchstat.Reporter{
-               Logger:     log.New(runner.hoststatLogger, "", 0),
-               Pid:        func() int { return 1 },
+               Logger: log.New(runner.hoststatLogger, "", 0),
+               // Our own cgroup is the "host" cgroup, in the sense
+               // that it accounts for resource usage outside the
+               // container. It doesn't count _all_ resource usage on
+               // the system.
+               //
+               // TODO?: Use the furthest ancestor of our own cgroup
+               // that has stats available. (Currently crunchstat
+               // does not have that capability.)
+               Pid:        os.Getpid,
                PollPeriod: runner.statInterval,
        }
        runner.hoststatReporter.Start()
@@ -1903,7 +1911,7 @@ func (command) RunCommand(prog string, args []string, stdin io.Reader, stdout, s
        statInterval := flags.Duration("crunchstat-interval", 10*time.Second, "sampling period for periodic resource usage reporting")
        flags.String("cgroup-root", "/sys/fs/cgroup", "path to sysfs cgroup tree (obsolete, ignored)")
        flags.String("cgroup-parent", "docker", "name of container's parent cgroup (obsolete, ignored)")
-       cgroupParentSubsystem := flags.String("cgroup-parent-subsystem", "", "use current cgroup for given subsystem as parent cgroup for container (cgroups v1 only)")
+       cgroupParentSubsystem := flags.String("cgroup-parent-subsystem", "", "use current cgroup for given `subsystem` as parent cgroup for container (subsystem argument is only relevant for cgroups v1; in cgroups v2 / unified mode, any non-empty value means use current cgroup)")
        caCertsPath := flags.String("ca-certs", "", "Path to TLS root certificates")
        detach := flags.Bool("detach", false, "Detach from parent process and run in the background")
        stdinConfig := flags.Bool("stdin-config", false, "Load config and environment variables from JSON message on stdin")
@@ -2131,7 +2139,7 @@ func (command) RunCommand(prog string, args []string, stdin io.Reader, stdout, s
        cr.enableNetwork = *enableNetwork
        cr.networkMode = *networkMode
        if *cgroupParentSubsystem != "" {
-               p, err := findCgroup(*cgroupParentSubsystem)
+               p, err := findCgroup(os.DirFS("/"), *cgroupParentSubsystem)
                if err != nil {
                        log.Printf("fatal: cgroup parent subsystem: %s", err)
                        return 1