Add support for optional cgroup attributes
Cgroup attributes like io.weight or io.bfq.weight only exist if the
corresponding I/O scheduler has been loaded. Hence add support for
ignoring failures to write to a cgroup attribute that does not exist.
Bug: 213617178
Test: This patch has been tested in combination with patch "Migrate the blkio controller to the cgroup v2 hierarchy".
Change-Id: I5debafabc4dd430a1b98ea343bf3740c764edcc3
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index dc7c368..4a2bf38 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -206,6 +206,14 @@
}
if (!WriteStringToFile(value_, path)) {
+ if (errno == ENOENT) {
+ if (optional_) {
+ return true;
+ } else {
+ LOG(ERROR) << "No such cgroup attribute: " << path;
+ return false;
+ }
+ }
PLOG(ERROR) << "Failed to write '" << value_ << "' to " << path;
return false;
}
@@ -675,11 +683,12 @@
} else if (action_name == "SetAttribute") {
std::string attr_name = params_val["Name"].asString();
std::string attr_value = params_val["Value"].asString();
+ bool optional = strcmp(params_val["Optional"].asString().c_str(), "true") == 0;
auto iter = attributes_.find(attr_name);
if (iter != attributes_.end()) {
- profile->Add(
- std::make_unique<SetAttributeAction>(iter->second.get(), attr_value));
+ profile->Add(std::make_unique<SetAttributeAction>(iter->second.get(),
+ attr_value, optional));
} else {
LOG(WARNING) << "SetAttribute: unknown attribute: " << attr_name;
}