jasder
/
runc
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Parse directly in FindCgroupMountpointDir 

Unify it with FindCgroupMountpoint, and add comments why
we should to do this.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
This commit is contained in:
Qiang Huang 2015-09-09 09:28:50 +08:00
parent 0f85e4e1a3
commit bc67941c72
1 changed files with 14 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
libcontainer/cgroups/utils.go
View File

@ -21,6 +21,9 @@ const cgroupNamePrefix = "name="
// https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt // https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt
func FindCgroupMountpoint(subsystem string) (string, error) { func FindCgroupMountpoint(subsystem string) (string, error) {
// We are not using mount.GetMounts() because it's super-inefficient,
// parsing it directly sped up x10 times because of not using Sscanf.
// It was one of two major performance drawbacks in container start.
f, err := os.Open("/proc/self/mountinfo") f, err := os.Open("/proc/self/mountinfo")
if err != nil { if err != nil {
return "", err return "", err
@ -69,16 +72,23 @@ func FindCgroupMountpointAndSource(subsystem string) (string, string, error) {
} }
func FindCgroupMountpointDir() (string, error) { func FindCgroupMountpointDir() (string, error) {
mounts, err := mount.GetMounts() f, err := os.Open("/proc/self/mountinfo")
if err != nil { if err != nil {
return "", err return "", err
} }
defer f.Close()
for _, mount := range mounts { scanner := bufio.NewScanner(f)
if mount.Fstype == "cgroup" { for scanner.Scan() {
return filepath.Dir(mount.Mountpoint), nil txt := scanner.Text()
fields := strings.Split(txt, " ")
if fields[7] == "cgroup" {
return filepath.Dir(fields[4]), nil
} }
} }
if err := scanner.Err(); err != nil {
return "", err
}
return "", NewNotFoundError("cgroup") return "", NewNotFoundError("cgroup")
} }