Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7f19b1e6 authored by Suren Baghdasaryan's avatar Suren Baghdasaryan
Browse files

libprocessgroup: introduce optional attribute for cgroup controllers 



Memory cgroup controller is not used by high-end Android devices and is
disabled in Android kernels 5.10+, however Android Go devices still
require this controller.
Similarly schedtune controller is being replaced with cpu controller's
utilclamp feature, however some devices are using older kernels which
only support schedtune.
To prevent spamming logcat with errors we need a way to mark a
controller optional in such cases without removing it from
cgroups.json file.
Introduce "Optional" attribute to cgroup controller's cgroups.json
description to accomodate these cases. When an optional controller
fails to mount due to lack of support in the kernel it will log an
informational message without generating further errors.

Bug: 181866655
Test: boot and observe libprocessgroup messages in logcat
Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Change-Id: Ib5bcfdd8d338704f3f9d8b326d8ddd88b67915a1
parent c19a7dd3

libprocessgroup/cgrouprc/include/android/cgrouprc.h

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ __attribute__((warn_unused_result)) uint32_t ACgroupController_getVersion(const 
 */

#define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1

#define CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION 0x2

#define CGROUPRC_CONTROLLER_FLAG_OPTIONAL 0x4



/**

 * Returns the flags bitmask of the given controller.

libprocessgroup/profiles/cgroups.json

+2 −1
Original line number Diff line number Diff line
@@ -26,7 +26,8 @@ 
      "Path": "/dev/memcg",

      "Mode": "0700",

      "UID": "root",

      "GID": "system"

      "GID": "system",

      "Optional": true

    }

  ],

  "Cgroups2": {

libprocessgroup/profiles/cgroups.proto

+2 −1
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ message Cgroups { 
    Cgroups2 cgroups2 = 2 [json_name = "Cgroups2"];

}



// Next: 7

// Next: 8

message Cgroup {

    string controller = 1 [json_name = "Controller"];

    string path = 2 [json_name = "Path"];
@@ -35,6 +35,7 @@ message Cgroup { 
// when a boolean is specified as false, so leave unspecified in that case

// https://developers.google.com/protocol-buffers/docs/proto3#default

    bool needs_activation = 6 [json_name = "NeedsActivation"];

    bool is_optional = 7 [json_name = "Optional"];

}



// Next: 6

libprocessgroup/profiles/cgroups_30.json

+2 −1
Original line number Diff line number Diff line
@@ -5,7 +5,8 @@ 
      "Path": "/dev/stune",

      "Mode": "0755",

      "UID": "system",

      "GID": "system"

      "GID": "system",

      "Optional": true

    }

  ]

}

libprocessgroup/setup/cgroup_map_write.cpp

+13 −2
Original line number Diff line number Diff line
@@ -161,6 +161,10 @@ static void MergeCgroupToDescriptors(std::map<std::string, CgroupDescriptor>* de 
        controller_flags |= CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION;

    }



    if (cgroup["Optional"].isBool() && cgroup["Optional"].asBool()) {

        controller_flags |= CGROUPRC_CONTROLLER_FLAG_OPTIONAL;

    }



    CgroupDescriptor descriptor(

            cgroups_version, name, path, std::strtoul(cgroup["Mode"].asString().c_str(), 0, 8),

            cgroup["UID"].asString(), cgroup["GID"].asString(), controller_flags);
@@ -308,9 +312,16 @@ static bool SetupCgroup(const CgroupDescriptor& descriptor) { 
    }



    if (result < 0) {

        bool optional = controller->flags() & CGROUPRC_CONTROLLER_FLAG_OPTIONAL;



        if (optional && errno == EINVAL) {

            // Optional controllers are allowed to fail to mount if kernel does not support them

            LOG(INFO) << "Optional " << controller->name() << " cgroup controller is not mounted";

        } else {

            PLOG(ERROR) << "Failed to mount " << controller->name() << " cgroup";

            return false;

        }

    }



    return true;

}