| 28 | } |
| 29 | |
| 30 | fs::path cgroupV2PathOfProcess() |
| 31 | { |
| 32 | #if defined(OS_LINUX) |
| 33 | chassert(cgroupsV2Enabled()); |
| 34 | /// All PIDs assigned to a cgroup are in /sys/fs/cgroups/{cgroup_name}/cgroup.procs |
| 35 | /// A simpler way to get the membership is: |
| 36 | std::ifstream cgroup_name_file("/proc/self/cgroup"); |
| 37 | if (!cgroup_name_file.is_open()) |
| 38 | return {}; |
| 39 | /// https://docs.kernel.org/admin-guide/cgroup-v2.html says: |
| 40 | /// /proc/$PID/cgroup” lists a process’s cgroup membership. If legacy cgroup is in use in the |
| 41 | /// system, this file may contain multiple lines, one for each hierarchy. The entry for cgroup |
| 42 | /// v2 is always in the format “0::$PATH”. |
| 43 | /// |
| 44 | /// So we're basically looking for a (v2) line with prefix "0::/", possibly among lines with |
| 45 | /// other prefixes belonging v1. Note: It is valid to have an empty name as 'root' cgroup v2. |
| 46 | static const std::string v2_prefix = "0::/"; |
| 47 | std::string cgroup; |
| 48 | while (std::getline(cgroup_name_file, cgroup)) |
| 49 | { |
| 50 | if (cgroup.starts_with(v2_prefix)) |
| 51 | { |
| 52 | cgroup = cgroup.substr(v2_prefix.length()); |
| 53 | return default_cgroups_mount / cgroup; |
| 54 | } |
| 55 | } |
| 56 | return {}; |
| 57 | #else |
| 58 | return {}; |
| 59 | #endif |
| 60 | } |
| 61 | |
| 62 | std::optional<std::string> getCgroupsV2PathContainingFile([[maybe_unused]] std::string_view file_name) |
| 63 | { |
no test coverage detected