1 files changed, 118 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/procfs/schedstat.go b/vendor/github.com/prometheus/procfs/schedstat.go
new file mode 100644
index 000000000..a4c4089ac
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/schedstat.go
@@ -0,0 +1,118 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+var (
+	cpuLineRE  = regexp.MustCompile(`cpu(\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+)`)
+	procLineRE = regexp.MustCompile(`(\d+) (\d+) (\d+)`)
+)
+
+// Schedstat contains scheduler statistics from /proc/schedstat
+//
+// See
+// https://www.kernel.org/doc/Documentation/scheduler/sched-stats.txt
+// for a detailed description of what these numbers mean.
+//
+// Note the current kernel documentation claims some of the time units are in
+// jiffies when they are actually in nanoseconds since 2.6.23 with the
+// introduction of CFS. A fix to the documentation is pending. See
+// https://lore.kernel.org/patchwork/project/lkml/list/?series=403473
+type Schedstat struct {
+	CPUs []*SchedstatCPU
+}
+
+// SchedstatCPU contains the values from one "cpu<N>" line
+type SchedstatCPU struct {
+	CPUNum string
+
+	RunningNanoseconds uint64
+	WaitingNanoseconds uint64
+	RunTimeslices      uint64
+}
+
+// ProcSchedstat contains the values from /proc/<pid>/schedstat
+type ProcSchedstat struct {
+	RunningNanoseconds uint64
+	WaitingNanoseconds uint64
+	RunTimeslices      uint64
+}
+
+// Schedstat reads data from /proc/schedstat
+func (fs FS) Schedstat() (*Schedstat, error) {
+	file, err := os.Open(fs.proc.Path("schedstat"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	stats := &Schedstat{}
+	scanner := bufio.NewScanner(file)
+
+	for scanner.Scan() {
+		match := cpuLineRE.FindStringSubmatch(scanner.Text())
+		if match != nil {
+			cpu := &SchedstatCPU{}
+			cpu.CPUNum = match[1]
+
+			cpu.RunningNanoseconds, err = strconv.ParseUint(match[8], 10, 64)
+			if err != nil {
+				continue
+			}
+
+			cpu.WaitingNanoseconds, err = strconv.ParseUint(match[9], 10, 64)
+			if err != nil {
+				continue
+			}
+
+			cpu.RunTimeslices, err = strconv.ParseUint(match[10], 10, 64)
+			if err != nil {
+				continue
+			}
+
+			stats.CPUs = append(stats.CPUs, cpu)
+		}
+	}
+
+	return stats, nil
+}
+
+func parseProcSchedstat(contents string) (stats ProcSchedstat, err error) {
+	match := procLineRE.FindStringSubmatch(contents)
+
+	if match != nil {
+		stats.RunningNanoseconds, err = strconv.ParseUint(match[1], 10, 64)
+		if err != nil {
+			return
+		}
+
+		stats.WaitingNanoseconds, err = strconv.ParseUint(match[2], 10, 64)
+		if err != nil {
+			return
+		}
+
+		stats.RunTimeslices, err = strconv.ParseUint(match[3], 10, 64)
+		return
+	}
+
+	err = errors.New("could not parse schedstat")
+	return
+}