platform_system_core/libcutils/iosched_policy.c

73 lines
1.7 KiB
C

/*
** Copyright 2007-2014, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_SCHED_H
#include <cutils/iosched_policy.h>
#ifdef HAVE_ANDROID_OS
/* #include <linux/ioprio.h> */
extern int ioprio_set(int which, int who, int ioprio);
extern int ioprio_get(int which, int who);
#define __android_unused
#else
#define __android_unused __attribute__((__unused__))
#endif
enum {
WHO_PROCESS = 1,
WHO_PGRP,
WHO_USER,
};
#define CLASS_SHIFT 13
#define IOPRIO_NORM 4
int android_set_ioprio(int pid __android_unused, IoSchedClass clazz __android_unused, int ioprio __android_unused) {
#ifdef HAVE_ANDROID_OS
if (ioprio_set(WHO_PROCESS, pid, ioprio | (clazz << CLASS_SHIFT))) {
return -1;
}
#endif
return 0;
}
int android_get_ioprio(int pid __android_unused, IoSchedClass *clazz, int *ioprio) {
#ifdef HAVE_ANDROID_OS
int rc;
if ((rc = ioprio_get(WHO_PROCESS, pid)) < 0) {
return -1;
}
*clazz = (rc >> CLASS_SHIFT);
*ioprio = (rc & 0xff);
#else
*clazz = IoSchedClass_NONE;
*ioprio = 0;
#endif
return 0;
}
#endif /* HAVE_SCHED_H */