libprocessgroup: optimize SetAttributeAction::ExecuteForProcess performance
Current implementation of SetAttributeAction::ExecuteForProcess reuses
SetAttributeAction::ExecuteForTask while not utilizing available uid/pid
information. This results in a call to GetPathForTask() which is an
expensive function due to it reading and parsing /proc/$pid/cgroups.
This can be avoided if we utilize available uid/pid info and the fact
that cgroup v2 attributes share the cgroup v2 hierarchy as process
groups, which use a known path template.
Bug: 292636609
Change-Id: I02e3046bd85d0dfebc68ab444f1796bb54cc69c7
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index 59b1350..f51b076 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -126,6 +126,16 @@
file_v2_name_ = file_v2_name;
}
+bool ProfileAttribute::GetPathForProcess(uid_t uid, pid_t pid, std::string* path) const {
+ if (controller()->version() == 2) {
+ // all cgroup v2 attributes use the same process group hierarchy
+ *path = StringPrintf("%s/uid_%u/pid_%d/%s", controller()->path(), uid, pid,
+ file_name().c_str());
+ return true;
+ }
+ return GetPathForTask(pid, path);
+}
+
bool ProfileAttribute::GetPathForTask(int tid, std::string* path) const {
std::string subgroup;
if (!controller()->GetTaskGroup(tid, &subgroup)) {
@@ -209,18 +219,7 @@
#endif
-bool SetAttributeAction::ExecuteForProcess(uid_t, pid_t pid) const {
- return ExecuteForTask(pid);
-}
-
-bool SetAttributeAction::ExecuteForTask(int tid) const {
- std::string path;
-
- if (!attribute_->GetPathForTask(tid, &path)) {
- LOG(ERROR) << "Failed to find cgroup for tid " << tid;
- return false;
- }
-
+bool SetAttributeAction::WriteValueToFile(const std::string& path) const {
if (!WriteStringToFile(value_, path)) {
if (access(path.c_str(), F_OK) < 0) {
if (optional_) {
@@ -240,6 +239,28 @@
return true;
}
+bool SetAttributeAction::ExecuteForProcess(uid_t uid, pid_t pid) const {
+ std::string path;
+
+ if (!attribute_->GetPathForProcess(uid, pid, &path)) {
+ LOG(ERROR) << "Failed to find cgroup for uid " << uid << " pid " << pid;
+ return false;
+ }
+
+ return WriteValueToFile(path);
+}
+
+bool SetAttributeAction::ExecuteForTask(int tid) const {
+ std::string path;
+
+ if (!attribute_->GetPathForTask(tid, &path)) {
+ LOG(ERROR) << "Failed to find cgroup for tid " << tid;
+ return false;
+ }
+
+ return WriteValueToFile(path);
+}
+
bool SetAttributeAction::ExecuteForUID(uid_t uid) const {
std::string path;