1 #ifndef ANDROID_DVR_PERFORMANCED_CPU_SET_H_ 2 #define ANDROID_DVR_PERFORMANCED_CPU_SET_H_ 3 4 #include <fcntl.h> 5 6 #include <memory> 7 #include <mutex> 8 #include <string> 9 #include <unordered_map> 10 #include <vector> 11 12 #include <android-base/unique_fd.h> 13 14 #include "unique_file.h" 15 16 namespace android { 17 namespace dvr { 18 19 class CpuSet { 20 public: 21 // Returns the parent group for this group, if any. This pointer is owned by 22 // the group hierarchy and is only valid as long as the hierarchy is valid. 23 CpuSet* parent() const { return parent_; } 24 std::string name() const { return name_; } 25 std::string path() const { return path_; } 26 27 bool IsRoot() const { return parent_ == nullptr; } 28 29 std::string GetCpuList() const; 30 31 int AttachTask(pid_t task_id) const; 32 std::vector<pid_t> GetTasks() const; 33 34 private: 35 friend class CpuSetManager; 36 37 CpuSet(CpuSet* parent, const std::string& name, base::unique_fd&& cpuset_fd); 38 39 void AddChild(std::unique_ptr<CpuSet> child); 40 41 base::unique_fd OpenPropertyFile(const std::string& name) const; 42 UniqueFile OpenPropertyFilePointer(const std::string& name) const; 43 44 base::unique_fd OpenFile(const std::string& name, int flags = O_RDONLY) const; 45 UniqueFile OpenFilePointer(const std::string& name, 46 int flags = O_RDONLY) const; 47 48 CpuSet* parent_; 49 std::string name_; 50 std::string path_; 51 base::unique_fd cpuset_fd_; 52 std::vector<std::unique_ptr<CpuSet>> children_; 53 54 static void SetPrefixEnabled(bool enabled) { prefix_enabled_ = enabled; } 55 static bool prefix_enabled_; 56 57 CpuSet(const CpuSet&) = delete; 58 void operator=(const CpuSet&) = delete; 59 }; 60 61 class CpuSetManager { 62 public: 63 CpuSetManager() {} 64 65 // Creats a CpuSet hierarchy by walking the directory tree starting at 66 // |cpuset_root|. This argument must be the path to the root cpuset for the 67 // system, which is usually /dev/cpuset. 68 void Load(const std::string& cpuset_root); 69 70 // Lookup and return a CpuSet from a cpuset path. Ownership of the pointer 71 // DOES NOT pass to the caller; the pointer remains valid as long as the 72 // CpuSet hierarchy is valid. 73 CpuSet* Lookup(const std::string& path); 74 75 // Returns a vector of all the cpusets found at initializaiton. Ownership of 76 // the pointers to CpuSets DOES NOT pass to the caller; the pointers remain 77 // valid as long as the CpuSet hierarchy is valid. 78 std::vector<CpuSet*> GetCpuSets(); 79 80 // Moves all unbound tasks from the root set into the target set. This is used 81 // to shield the system from interference from unbound kernel threads. 82 void MoveUnboundTasks(const std::string& target_set); 83 84 std::string DumpState() const; 85 86 operator bool() const { return root_set_ != nullptr; } 87 88 private: 89 // Creates a CpuSet from a path to a cpuset cgroup directory. Recursively 90 // creates child groups for each directory found under |path|. 91 std::unique_ptr<CpuSet> Create(const std::string& path); 92 std::unique_ptr<CpuSet> Create(base::unique_fd base_fd, 93 const std::string& name, CpuSet* parent); 94 95 std::unique_ptr<CpuSet> root_set_; 96 std::unordered_map<std::string, CpuSet*> path_map_; 97 98 CpuSetManager(const CpuSetManager&) = delete; 99 void operator=(const CpuSetManager&) = delete; 100 }; 101 102 } // namespace dvr 103 } // namespace android 104 105 #endif // ANDROID_DVR_PERFORMANCED_CPU_SET_H_ 106
