diff options
| -rw-r--r-- | runsc/boot/config.go | 9 | ||||
| -rw-r--r-- | runsc/cgroup/cgroup.go | 24 | ||||
| -rw-r--r-- | runsc/main.go | 2 | ||||
| -rw-r--r-- | runsc/sandbox/sandbox.go | 21 |
4 files changed, 56 insertions, 0 deletions
diff --git a/runsc/boot/config.go b/runsc/boot/config.go index 72a33534f..a878bc2ce 100644 --- a/runsc/boot/config.go +++ b/runsc/boot/config.go @@ -250,6 +250,12 @@ type Config struct { // multiple tests are run in parallel, since there is no way to pass // parameters to the runtime from docker. TestOnlyTestNameEnv string + + // CPUNumFromQuota sets CPU number count to available CPU quota, using + // least integer value greater than or equal to quota. + // + // E.g. 0.2 CPU quota will result in 1, and 1.9 in 2. + CPUNumFromQuota bool } // ToFlags returns a slice of flags that correspond to the given Config. @@ -282,6 +288,9 @@ func (c *Config) ToFlags() []string { "--software-gso=" + strconv.FormatBool(c.SoftwareGSO), "--overlayfs-stale-read=" + strconv.FormatBool(c.OverlayfsStaleRead), } + if c.CPUNumFromQuota { + f = append(f, "--cpu-num-from-quota") + } // Only include these if set since it is never to be used by users. if c.TestOnlyAllowRunAsCurrentUserWithoutChroot { f = append(f, "--TESTONLY-unsafe-nonroot=true") diff --git a/runsc/cgroup/cgroup.go b/runsc/cgroup/cgroup.go index ab3a25b9b..653ca5f52 100644 --- a/runsc/cgroup/cgroup.go +++ b/runsc/cgroup/cgroup.go @@ -101,6 +101,14 @@ func getValue(path, name string) (string, error) { return string(out), nil } +func getInt(path, name string) (int, error) { + s, err := getValue(path, name) + if err != nil { + return 0, err + } + return strconv.Atoi(strings.TrimSpace(s)) +} + // fillFromAncestor sets the value of a cgroup file from the first ancestor // that has content. It does nothing if the file in 'path' has already been set. func fillFromAncestor(path string) (string, error) { @@ -323,6 +331,22 @@ func (c *Cgroup) Join() (func(), error) { return undo, nil } +func (c *Cgroup) CPUQuota() (float64, error) { + path := c.makePath("cpu") + quota, err := getInt(path, "cpu.cfs_quota_us") + if err != nil { + return -1, err + } + period, err := getInt(path, "cpu.cfs_period_us") + if err != nil { + return -1, err + } + if quota <= 0 || period <= 0 { + return -1, err + } + return float64(quota) / float64(period), nil +} + // NumCPU returns the number of CPUs configured in 'cpuset/cpuset.cpus'. func (c *Cgroup) NumCPU() (int, error) { path := c.makePath("cpuset") diff --git a/runsc/main.go b/runsc/main.go index 4682b308c..abf929511 100644 --- a/runsc/main.go +++ b/runsc/main.go @@ -82,6 +82,7 @@ var ( numNetworkChannels = flag.Int("num-network-channels", 1, "number of underlying channels(FDs) to use for network link endpoints.") rootless = flag.Bool("rootless", false, "it allows the sandbox to be started with a user that is not root. Sandbox and Gofer processes may run with same privileges as current user.") referenceLeakMode = flag.String("ref-leak-mode", "disabled", "sets reference leak check mode: disabled (default), log-names, log-traces.") + cpuNumFromQuota = flag.Bool("cpu-num-from-quota", false, "set cpu number to cpu quota (least integer greater or equal to quota value, but not less than 2)") // Test flags, not to be used outside tests, ever. testOnlyAllowRunAsCurrentUserWithoutChroot = flag.Bool("TESTONLY-unsafe-nonroot", false, "TEST ONLY; do not ever use! This skips many security measures that isolate the host from the sandbox.") @@ -225,6 +226,7 @@ func main() { AlsoLogToStderr: *alsoLogToStderr, ReferenceLeakMode: refsLeakMode, OverlayfsStaleRead: *overlayfsStaleRead, + CPUNumFromQuota: *cpuNumFromQuota, TestOnlyAllowRunAsCurrentUserWithoutChroot: *testOnlyAllowRunAsCurrentUserWithoutChroot, TestOnlyTestNameEnv: *testOnlyTestNameEnv, diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go index 805233184..ce1452b87 100644 --- a/runsc/sandbox/sandbox.go +++ b/runsc/sandbox/sandbox.go @@ -18,6 +18,7 @@ package sandbox import ( "context" "fmt" + "math" "os" "os/exec" "strconv" @@ -631,6 +632,26 @@ func (s *Sandbox) createSandboxProcess(conf *boot.Config, args *Args, startSyncF if err != nil { return fmt.Errorf("getting cpu count from cgroups: %v", err) } + if conf.CPUNumFromQuota { + // Dropping below 2 CPUs can trigger application to disable + // locks that can lead do hard to debug errors, so just + // leaving two cores as reasonable default. + const minCPUs = 2 + + quota, err := s.Cgroup.CPUQuota() + if err != nil { + return fmt.Errorf("getting cpu qouta from cgroups: %v", err) + } + if n := int(math.Ceil(quota)); n > 0 { + if n < minCPUs { + n = minCPUs + } + if n < cpuNum { + // Only lower the cpu number. + cpuNum = n + } + } + } cmd.Args = append(cmd.Args, "--cpu-num", strconv.Itoa(cpuNum)) mem, err := s.Cgroup.MemoryLimit() |