Merge pull request #1120 from kailun-qin/add-cfs-burst

config-linux: add CFS bandwidth burst

Author: AkihiroSuda

config-linux.md

@@ -365,6 +365,9 @@ The following parameters can be specified to set up the controller:
 
 * **`shares`** *(uint64, OPTIONAL)* - specifies a relative share of CPU time available to the tasks in a cgroup
 * **`quota`** *(int64, OPTIONAL)* - specifies the total amount of time in microseconds for which all tasks in a cgroup can run during one period (as defined by **`period`** below)
+    If specified with any (valid) positive value, it MUST be no smaller than `burst` (runtimes MAY generate an error).
+* **`burst`** *(uint64, OPTIONAL)* - specifies the maximum amount of accumulated time in microseconds for which all tasks in a cgroup can run additionally for burst during one period (as defined by **`period`** below)
+    If specified, this value MUST be no larger than any positive `quota` (runtimes MAY generate an error).
 * **`period`** *(uint64, OPTIONAL)* - specifies a period of time in microseconds for how regularly a cgroup's access to CPU resources should be reallocated (CFS scheduler only)
 * **`realtimeRuntime`** *(int64, OPTIONAL)* - specifies a period of time in microseconds for the longest continuous period in which the tasks in a cgroup have access to CPU resources
 * **`realtimePeriod`** *(uint64, OPTIONAL)* - same as **`period`** but applies to realtime scheduler only
@@ -378,6 +381,7 @@ The following parameters can be specified to set up the controller:
 "cpu": {
     "shares": 1024,
     "quota": 1000000,
+    "burst": 1000000,
     "period": 500000,
     "realtimeRuntime": 950000,
     "realtimePeriod": 1000000,

schema/config-linux.json

@@ -110,6 +110,9 @@
                             "quota": {
                                 "$ref": "defs.json#/definitions/int64"
                             },
+                            "burst": {
+                                "$ref": "defs.json#/definitions/uint64"
+                            },
                             "realtimePeriod": {
                                 "$ref": "defs.json#/definitions/uint64"
                             },

schema/test/config/good/spec-example.json

@@ -276,6 +276,7 @@
             "cpu": {
                 "shares": 1024,
                 "quota": 1000000,
+                "burst": 1000000,
                 "period": 500000,
                 "realtimeRuntime": 950000,
                 "realtimePeriod": 1000000,

specs-go/config.go

@@ -331,6 +331,9 @@ type LinuxCPU struct {
 	Shares *uint64 `json:"shares,omitempty"`
 	// CPU hardcap limit (in usecs). Allowed cpu time in a given period.
 	Quota *int64 `json:"quota,omitempty"`
+	// CPU hardcap burst limit (in usecs). Allowed accumulated cpu time additionally for burst in a
+	// given period.
+	Burst *uint64 `json:"burst,omitempty"`
 	// CPU period to be used for hardcapping (in usecs).
 	Period *uint64 `json:"period,omitempty"`
 	// How much time realtime scheduling may use (in usecs).