Modify priority tweaking to use CGroups.
This modifies the behavior of setpriority and getpriority
to use CGroups rather than niceness levels.
I've removed the unittest comparing priorities as its not
really valid any more as we are just writing numbers to files.
I've also refactored references to priority to reference cpu
shares etc.
BUG=chromium-os:36229
TEST=Unittest + doing end to end test in bgnd
CQ-DEPEND=I6a0e56073e7281268e0550919c9ec9202b18db26
Change-Id: I48c8270c2065f1e0677e5e53df3557131577b97c
Reviewed-on: https://gerrit.chromium.org/gerrit/39147
Reviewed-by: Chris Sosa <[email protected]>
Tested-by: Chris Sosa <[email protected]>
Commit-Ready: Chris Sosa <[email protected]>
diff --git a/utils.cc b/utils.cc
index 1267256..b4763e4 100644
--- a/utils.cc
+++ b/utils.cc
@@ -56,6 +56,10 @@
static const char kDevImageMarker[] = "/root/.dev_mode";
const char* const kStatefulPartition = "/mnt/stateful_partition";
+// Cgroup container is created in update-engine's upstart script located at
+// /etc/init/update-engine.conf.
+static const char kCGroupDir[] = "/sys/fs/cgroup/cpu/update-engine";
+
bool IsOfficialBuild() {
return !file_util::PathExists(FilePath(kDevImageMarker));
}
@@ -624,16 +628,23 @@
g_idle_add(&TriggerCrashReporterUpload, NULL);
}
-bool SetProcessPriority(ProcessPriority priority) {
- int prio = static_cast<int>(priority);
- LOG(INFO) << "Setting process priority to " << prio;
- TEST_AND_RETURN_FALSE(setpriority(PRIO_PROCESS, 0, prio) == 0);
- return true;
+bool SetCpuShares(CpuShares shares) {
+ string string_shares = base::IntToString(static_cast<int>(shares));
+ string cpu_shares_file = string(utils::kCGroupDir) + "/cpu.shares";
+ LOG(INFO) << "Setting cgroup cpu shares to " << string_shares;
+ if(utils::WriteFile(cpu_shares_file.c_str(), string_shares.c_str(),
+ string_shares.size())){
+ return true;
+ } else {
+ LOG(ERROR) << "Failed to change cgroup cpu shares to "<< string_shares
+ << " using " << cpu_shares_file;
+ return false;
+ }
}
-int ComparePriorities(ProcessPriority priority_lhs,
- ProcessPriority priority_rhs) {
- return static_cast<int>(priority_rhs) - static_cast<int>(priority_lhs);
+int CompareCpuShares(CpuShares shares_lhs,
+ CpuShares shares_rhs) {
+ return static_cast<int>(shares_lhs) - static_cast<int>(shares_rhs);
}
int FuzzInt(int value, unsigned int range) {
