1 2 /* libs/cutils/iosched_policy.c 3 ** 4 ** Copyright 2007, The Android Open Source Project 5 ** 6 ** Licensed under the Apache License, Version 2.0 (the "License"); 7 ** you may not use this file except in compliance with the License. 8 ** You may obtain a copy of the License at 9 ** 10 ** http://www.apache.org/licenses/LICENSE-2.0 11 ** 12 ** Unless required by applicable law or agreed to in writing, software 13 ** distributed under the License is distributed on an "AS IS" BASIS, 14 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 ** See the License for the specific language governing permissions and 16 ** limitations under the License. 17 */ 18 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <unistd.h> 22 #include <string.h> 23 #include <errno.h> 24 #include <fcntl.h> 25 26 #ifdef HAVE_SCHED_H 27 28 #include <cutils/iosched_policy.h> 29 30 extern int ioprio_set(int which, int who, int ioprio); 31 32 enum { 33 WHO_PROCESS = 1, 34 WHO_PGRP, 35 WHO_USER, 36 }; 37 38 #define CLASS_SHIFT 13 39 #define IOPRIO_NORM 4 40 41 int android_set_ioprio(int pid, IoSchedClass clazz, int ioprio) { 42 #ifdef HAVE_ANDROID_OS 43 if (ioprio_set(WHO_PROCESS, pid, ioprio | (clazz << CLASS_SHIFT))) { 44 return -1; 45 } 46 #endif 47 return 0; 48 } 49 50 int android_get_ioprio(int pid, IoSchedClass *clazz, int *ioprio) { 51 #ifdef HAVE_ANDROID_OS 52 int rc; 53 54 if ((rc = ioprio_get(WHO_PROCESS, pid)) < 0) { 55 return -1; 56 } 57 58 *clazz = (rc >> CLASS_SHIFT); 59 *ioprio = (rc & 0xff); 60 #else 61 *clazz = IoSchedClass_NONE; 62 *ioprio = 0; 63 #endif 64 return 0; 65 } 66 67 #endif /* HAVE_SCHED_H */ 68
