platform_system_core/libcutils/iosched_policy.c

59 lines
1.6 KiB
C

/*
** Copyright 2007, 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>
#include <cutils/iosched_policy.h>
#ifdef HAVE_ANDROID_OS
#include <linux/ioprio.h>
#include <sys/syscall.h>
#define __android_unused
#else
#define __android_unused __attribute__((__unused__))
#endif
int android_set_ioprio(int pid __android_unused, IoSchedClass clazz __android_unused, int ioprio __android_unused) {
#ifdef HAVE_ANDROID_OS
if (syscall(SYS_ioprio_set, IOPRIO_WHO_PROCESS, pid, ioprio | (clazz << IOPRIO_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 = syscall(SYS_ioprio_get, IOPRIO_WHO_PROCESS, pid)) < 0) {
return -1;
}
*clazz = (rc >> IOPRIO_CLASS_SHIFT);
*ioprio = (rc & 0xff);
#else
*clazz = IoSchedClass_NONE;
*ioprio = 0;
#endif
return 0;
}