libprocessgroup: add flags to indicate when a controller failed to mount
Controllers listed in cgroups.json file might fail to mount if kernel is
not configured to support them. We need a way to indicate whether a
controller was successfully mounted and is usable to avoid logging errors
and warnings when a controller that failed to mount is being used. Add
flags bitmask to cgrouprc controller descriptor and use a bit to indicate
that controller is successfully mounted. Modify cpusets_enabled() and
schedboost_enabled() functions to use this bit and report the actual
availability of the controller.
Bug: 124080437
Test: libcutils_test with cpuset and schedtune controllers disabled
Change-Id: I770cc39fe50465146e3205aacf77dc3c56923c5d
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index 6cd6b6e..92fcd1e 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -67,6 +67,13 @@
return controller_ != nullptr;
}
+bool CgroupController::IsUsable() const {
+ if (!HasValue()) return false;
+
+ uint32_t flags = ACgroupController_getFlags(controller_);
+ return (flags & CGROUPRC_CONTROLLER_FLAG_MOUNTED) != 0;
+}
+
std::string CgroupController::GetTasksFilePath(const std::string& rel_path) const {
std::string tasks_path = path();
@@ -153,6 +160,7 @@
const ACgroupController* controller = ACgroupFile_getController(i);
LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
<< ACgroupController_getVersion(controller) << " path "
+ << ACgroupController_getFlags(controller) << " flags "
<< ACgroupController_getPath(controller);
}
}
diff --git a/libprocessgroup/cgroup_map.h b/libprocessgroup/cgroup_map.h
index d765e60..9350412 100644
--- a/libprocessgroup/cgroup_map.h
+++ b/libprocessgroup/cgroup_map.h
@@ -38,6 +38,7 @@
const char* path() const;
bool HasValue() const;
+ bool IsUsable() const;
std::string GetTasksFilePath(const std::string& path) const;
std::string GetProcsFilePath(const std::string& path, uid_t uid, pid_t pid) const;
diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
index 6848620..9d5afeb 100644
--- a/libprocessgroup/cgrouprc/Android.bp
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -42,19 +42,19 @@
"libcgrouprc_format",
],
stubs: {
- symbol_file: "libcgrouprc.map.txt",
+ symbol_file: "libcgrouprc.llndk.txt",
versions: ["29"],
},
target: {
linux: {
- version_script: "libcgrouprc.map.txt",
+ version_script: "libcgrouprc.llndk.txt",
},
},
}
llndk_library {
name: "libcgrouprc",
- symbol_file: "libcgrouprc.map.txt",
+ symbol_file: "libcgrouprc.llndk.txt",
export_include_dirs: [
"include",
],
diff --git a/libprocessgroup/cgrouprc/cgroup_controller.cpp b/libprocessgroup/cgrouprc/cgroup_controller.cpp
index d064d31..5a326e5 100644
--- a/libprocessgroup/cgrouprc/cgroup_controller.cpp
+++ b/libprocessgroup/cgrouprc/cgroup_controller.cpp
@@ -27,6 +27,11 @@
return controller->version();
}
+uint32_t ACgroupController_getFlags(const ACgroupController* controller) {
+ CHECK(controller != nullptr);
+ return controller->flags();
+}
+
const char* ACgroupController_getName(const ACgroupController* controller) {
CHECK(controller != nullptr);
return controller->name();
diff --git a/libprocessgroup/cgrouprc/include/android/cgrouprc.h b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
index 4edd239..ffc9f0b 100644
--- a/libprocessgroup/cgrouprc/include/android/cgrouprc.h
+++ b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
@@ -66,6 +66,18 @@
__INTRODUCED_IN(29);
/**
+ * Flag bitmask used in ACgroupController_getFlags
+ */
+#define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
+
+/**
+ * Returns the flags bitmask of the given controller.
+ * If the given controller is null, return 0.
+ */
+__attribute__((warn_unused_result)) uint32_t ACgroupController_getFlags(const ACgroupController*)
+ __INTRODUCED_IN(29);
+
+/**
* Returns the name of the given controller.
* If the given controller is null, return nullptr.
*/
diff --git a/libprocessgroup/cgrouprc/libcgrouprc.map.txt b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
similarity index 88%
rename from libprocessgroup/cgrouprc/libcgrouprc.map.txt
rename to libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
index 91df392..ea3df33 100644
--- a/libprocessgroup/cgrouprc/libcgrouprc.map.txt
+++ b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
@@ -4,6 +4,7 @@
ACgroupFile_getControllerCount;
ACgroupFile_getController;
ACgroupController_getVersion;
+ ACgroupController_getFlags;
ACgroupController_getName;
ACgroupController_getPath;
local:
diff --git a/libprocessgroup/cgrouprc_format/cgroup_controller.cpp b/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
index 877eed8..202b23e 100644
--- a/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
+++ b/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
@@ -20,12 +20,19 @@
namespace cgrouprc {
namespace format {
-CgroupController::CgroupController(uint32_t version, const std::string& name,
- const std::string& path) {
+CgroupController::CgroupController() : version_(0), flags_(0) {
+ memset(name_, 0, sizeof(name_));
+ memset(path_, 0, sizeof(path_));
+}
+
+CgroupController::CgroupController(uint32_t version, uint32_t flags, const std::string& name,
+ const std::string& path)
+ : CgroupController() {
// strlcpy isn't available on host. Although there is an implementation
// in licutils, libcutils itself depends on libcgrouprc_format, causing
// a circular dependency.
version_ = version;
+ flags_ = flags;
strncpy(name_, name.c_str(), sizeof(name_) - 1);
name_[sizeof(name_) - 1] = '\0';
strncpy(path_, path.c_str(), sizeof(path_) - 1);
@@ -36,6 +43,10 @@
return version_;
}
+uint32_t CgroupController::flags() const {
+ return flags_;
+}
+
const char* CgroupController::name() const {
return name_;
}
@@ -44,6 +55,10 @@
return path_;
}
+void CgroupController::set_flags(uint32_t flags) {
+ flags_ = flags;
+}
+
} // namespace format
} // namespace cgrouprc
} // namespace android
diff --git a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
index 64c7532..40d8548 100644
--- a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
+++ b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
@@ -26,18 +26,23 @@
// Minimal controller description to be mmapped into process address space
struct CgroupController {
public:
- CgroupController() {}
- CgroupController(uint32_t version, const std::string& name, const std::string& path);
+ CgroupController();
+ CgroupController(uint32_t version, uint32_t flags, const std::string& name,
+ const std::string& path);
uint32_t version() const;
+ uint32_t flags() const;
const char* name() const;
const char* path() const;
+ void set_flags(uint32_t flags);
+
private:
static constexpr size_t CGROUP_NAME_BUF_SZ = 16;
static constexpr size_t CGROUP_PATH_BUF_SZ = 32;
uint32_t version_;
+ uint32_t flags_;
char name_[CGROUP_NAME_BUF_SZ];
char path_[CGROUP_PATH_BUF_SZ];
};
diff --git a/libprocessgroup/processgroup.cpp b/libprocessgroup/processgroup.cpp
index 1485ae9..d3ac26b 100644
--- a/libprocessgroup/processgroup.cpp
+++ b/libprocessgroup/processgroup.cpp
@@ -106,8 +106,7 @@
}
static bool isMemoryCgroupSupported() {
- std::string cgroup_name;
- static bool memcg_supported = CgroupMap::GetInstance().FindController("memory").HasValue();
+ static bool memcg_supported = CgroupMap::GetInstance().FindController("memory").IsUsable();
return memcg_supported;
}
diff --git a/libprocessgroup/sched_policy.cpp b/libprocessgroup/sched_policy.cpp
index fe4f93b..15f8139 100644
--- a/libprocessgroup/sched_policy.cpp
+++ b/libprocessgroup/sched_policy.cpp
@@ -151,19 +151,19 @@
}
bool cpusets_enabled() {
- static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").HasValue());
+ static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").IsUsable());
return enabled;
}
bool schedboost_enabled() {
- static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").HasValue());
+ static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").IsUsable());
return enabled;
}
static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
auto controller = CgroupMap::GetInstance().FindController(subsys);
- if (!controller.HasValue()) return -1;
+ if (!controller.IsUsable()) return -1;
if (!controller.GetTaskGroup(tid, &subgroup)) {
LOG(ERROR) << "Failed to find cgroup for tid " << tid;
diff --git a/libprocessgroup/setup/cgroup_descriptor.h b/libprocessgroup/setup/cgroup_descriptor.h
index 597060e..f029c4f 100644
--- a/libprocessgroup/setup/cgroup_descriptor.h
+++ b/libprocessgroup/setup/cgroup_descriptor.h
@@ -32,6 +32,8 @@
std::string uid() const { return uid_; }
std::string gid() const { return gid_; }
+ void set_mounted(bool mounted);
+
private:
format::CgroupController controller_;
mode_t mode_ = 0;
diff --git a/libprocessgroup/setup/cgroup_map_write.cpp b/libprocessgroup/setup/cgroup_map_write.cpp
index da60948..17ea06e 100644
--- a/libprocessgroup/setup/cgroup_map_write.cpp
+++ b/libprocessgroup/setup/cgroup_map_write.cpp
@@ -35,6 +35,7 @@
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
+#include <android/cgrouprc.h>
#include <json/reader.h>
#include <json/value.h>
#include <processgroup/format/cgroup_file.h>
@@ -267,7 +268,17 @@
CgroupDescriptor::CgroupDescriptor(uint32_t version, const std::string& name,
const std::string& path, mode_t mode, const std::string& uid,
const std::string& gid)
- : controller_(version, name, path), mode_(mode), uid_(uid), gid_(gid) {}
+ : controller_(version, 0, name, path), mode_(mode), uid_(uid), gid_(gid) {}
+
+void CgroupDescriptor::set_mounted(bool mounted) {
+ uint32_t flags = controller_.flags();
+ if (mounted) {
+ flags |= CGROUPRC_CONTROLLER_FLAG_MOUNTED;
+ } else {
+ flags &= ~CGROUPRC_CONTROLLER_FLAG_MOUNTED;
+ }
+ controller_.set_flags(flags);
+}
} // namespace cgrouprc
} // namespace android
@@ -296,10 +307,11 @@
}
// setup cgroups
- for (const auto& [name, descriptor] : descriptors) {
- if (!SetupCgroup(descriptor)) {
+ for (auto& [name, descriptor] : descriptors) {
+ if (SetupCgroup(descriptor)) {
+ descriptor.set_mounted(true);
+ } else {
// issue a warning and proceed with the next cgroup
- // TODO: mark the descriptor as invalid and skip it in WriteRcFile()
LOG(WARNING) << "Failed to setup " << name << " cgroup";
}
}