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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef __CUTILS_SCHED_POLICY_H
     18 #define __CUTILS_SCHED_POLICY_H
     19 
     20 #include <stdbool.h>
     21 
     22 #ifdef __cplusplus
     23 extern "C" {
     24 #endif
     25 
     26 /*
     27  * Check if Linux kernel enables CPUSETS feature.
     28  *
     29  * Return value: 1 if Linux kernel CONFIG_CPUSETS=y; 0 otherwise.
     30  */
     31 extern bool cpusets_enabled();
     32 
     33 /*
     34  * Check if Linux kernel enables SCHEDTUNE feature (only available in Android
     35  * common kernel or Linaro LSK, not in mainline Linux as of v4.9)
     36  *
     37  * Return value: 1 if Linux kernel CONFIG_CGROUP_SCHEDTUNE=y; 0 otherwise.
     38  */
     39 extern bool schedboost_enabled();
     40 
     41 /* Keep in sync with THREAD_GROUP_* in frameworks/base/core/java/android/os/Process.java */
     42 typedef enum {
     43     SP_DEFAULT    = -1,
     44     SP_BACKGROUND = 0,
     45     SP_FOREGROUND = 1,
     46     SP_SYSTEM     = 2,  // can't be used with set_sched_policy()
     47     SP_AUDIO_APP  = 3,
     48     SP_AUDIO_SYS  = 4,
     49     SP_TOP_APP    = 5,
     50     SP_RT_APP     = 6,
     51     SP_CNT,
     52     SP_MAX        = SP_CNT - 1,
     53     SP_SYSTEM_DEFAULT = SP_FOREGROUND,
     54 } SchedPolicy;
     55 
     56 extern int set_cpuset_policy(int tid, SchedPolicy policy);
     57 
     58 /* Assign thread tid to the cgroup associated with the specified policy.
     59  * If the thread is a thread group leader, that is it's gettid() == getpid(),
     60  * then the other threads in the same thread group are _not_ affected.
     61  * On platforms which support gettid(), zero tid means current thread.
     62  * Return value: 0 for success, or -errno for error.
     63  */
     64 extern int set_sched_policy(int tid, SchedPolicy policy);
     65 
     66 /* Return the policy associated with the cgroup of thread tid via policy pointer.
     67  * On platforms which support gettid(), zero tid means current thread.
     68  * Return value: 0 for success, or -1 for error and set errno.
     69  */
     70 extern int get_sched_policy(int tid, SchedPolicy *policy);
     71 
     72 /* Return a displayable string corresponding to policy.
     73  * Return value: non-NULL NUL-terminated name of unspecified length;
     74  * the caller is responsible for displaying the useful part of the string.
     75  */
     76 extern const char *get_sched_policy_name(SchedPolicy policy);
     77 
     78 #ifdef __cplusplus
     79 }
     80 #endif
     81 
     82 #endif /* __CUTILS_SCHED_POLICY_H */
     83