3826: Move cpu-counting into a function.

diff --git a/services/crunchstat/crunchstat.go b/services/crunchstat/crunchstat.go
index bd91aa0dec752605ede06b054f8031afd25687b6..89086f35b7589dda989c2301175a5f7e3a8e4c60 100644 (file)
--- a/services/crunchstat/crunchstat.go
+++ b/services/crunchstat/crunchstat.go
@@ -283,7 +283,32 @@ type CpuSample struct {
        cpus       int64
 }
 
-func DoCpuStats(stderr chan<- string, cgroup Cgroup, cpus int64, user_hz float64, lastSample *CpuSample) (*CpuSample) {
+// Return the number of CPUs available in the container. Return 0 if
+// we can't figure out the real number of CPUs.
+func GetCpuCount(stderr chan<- string, cgroup Cgroup) (int64) {
+       cpuset_cpus := FindStat(stderr, cgroup, "cpuset", "cpuset.cpus")
+       if cpuset_cpus == "" {
+               return 0
+       }
+       b, err := OpenAndReadAll(cpuset_cpus, stderr)
+       if err != nil {
+               return 0
+       }
+       sp := strings.Split(string(b), ",")
+       cpus := int64(0)
+       for _, v := range sp {
+               var min, max int64
+               n, _ := fmt.Sscanf(v, "%d-%d", &min, &max)
+               if n == 2 {
+                       cpus += (max - min) + 1
+               } else {
+                       cpus += 1
+               }
+       }
+       return cpus
+}
+
+func DoCpuStats(stderr chan<- string, cgroup Cgroup, lastSample *CpuSample) (*CpuSample) {
        cpuacct_stat := FindStat(stderr, cgroup, "cpuacct", "cpuacct.stat")
        if cpuacct_stat == "" {
                return lastSample
@@ -292,9 +317,11 @@ func DoCpuStats(stderr chan<- string, cgroup Cgroup, cpus int64, user_hz float64
        if err != nil {
                return lastSample
        }
-       nextSample := &CpuSample{time.Now(), 0, 0, cpus}
+
+       nextSample := &CpuSample{time.Now(), 0, 0, GetCpuCount(stderr, cgroup)}
        var userTicks, sysTicks int64
        fmt.Sscanf(string(b), "user %d\nsystem %d", &nextSample.user, &nextSample.sys)
+       user_hz := float64(C.sysconf(C._SC_CLK_TCK))
        nextSample.user = float64(userTicks) / user_hz
        nextSample.sys = float64(sysTicks) / user_hz
 
@@ -306,15 +333,11 @@ func DoCpuStats(stderr chan<- string, cgroup Cgroup, cpus int64, user_hz float64
                        nextSample.sys - lastSample.sys)
        }
        stderr <- fmt.Sprintf("crunchstat: cpu %.4f user %.4f sys %d cpus%s",
-               nextSample.user, nextSample.sys, cpus, delta)
+               nextSample.user, nextSample.sys, nextSample.cpus, delta)
        return nextSample
 }
 
 func PollCgroupStats(cgroup Cgroup, stderr chan string, poll int64, stop_poll_chan <-chan bool) {
-       var last_cpucount int64 = 0
-
-       user_hz := float64(C.sysconf(C._SC_CLK_TCK))
-
        var lastNetSample map[string]IoSample = nil
        var lastDiskSample map[string]IoSample = nil
        var lastCpuSample *CpuSample = nil
@@ -335,29 +358,8 @@ func PollCgroupStats(cgroup Cgroup, stderr chan string, poll int64, stop_poll_ch
                case <-poll_chan:
                        // Emit stats, then select again.
                }
-               cpuset_cpus := FindStat(stderr, cgroup, "cpuset", "cpuset.cpus")
-               if cpuset_cpus != "" {
-                       b, err := OpenAndReadAll(cpuset_cpus, stderr)
-                       if err != nil {
-                               // cgroup probably gone -- skip other stats too.
-                               continue
-                       }
-                       sp := strings.Split(string(b), ",")
-                       cpus := int64(0)
-                       for _, v := range sp {
-                               var min, max int64
-                               n, _ := fmt.Sscanf(v, "%d-%d", &min, &max)
-                               if n == 2 {
-                                       cpus += (max - min) + 1
-                               } else {
-                                       cpus += 1
-                               }
-                       }
-                       last_cpucount = cpus
-               }
-
                DoMemoryStats(stderr, cgroup)
-               lastCpuSample = DoCpuStats(stderr, cgroup, last_cpucount, user_hz, lastCpuSample)
+               lastCpuSample = DoCpuStats(stderr, cgroup, lastCpuSample)
                lastDiskSample = DoBlkIoStats(stderr, cgroup, lastDiskSample)
                lastNetSample = DoNetworkStats(stderr, cgroup, lastNetSample)
        }