1 /* 2 * Copyright (c) 2012 SUSE LINUX Products GmbH 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see 16 * <http://www.gnu.org/licenses/gpl-2.0.html> 17 */ 18 19 #ifndef SYSEMU_CPU_THROTTLE_H 20 #define SYSEMU_CPU_THROTTLE_H 21 22 #include "qemu/timer.h" 23 24 /** 25 * cpu_throttle_init: 26 * 27 * Initialize the CPU throttling API. 28 */ 29 void cpu_throttle_init(void); 30 31 /** 32 * cpu_throttle_set: 33 * @new_throttle_pct: Percent of sleep time. Valid range is 1 to 99. 34 * 35 * Throttles all vcpus by forcing them to sleep for the given percentage of 36 * time. A throttle_percentage of 25 corresponds to a 75% duty cycle roughly. 37 * (example: 10ms sleep for every 30ms awake). 38 * 39 * cpu_throttle_set can be called as needed to adjust new_throttle_pct. 40 * Once the throttling starts, it will remain in effect until cpu_throttle_stop 41 * is called. 42 */ 43 void cpu_throttle_set(int new_throttle_pct); 44 45 /** 46 * cpu_throttle_stop: 47 * 48 * Stops the vcpu throttling started by cpu_throttle_set. 49 */ 50 void cpu_throttle_stop(void); 51 52 /** 53 * cpu_throttle_active: 54 * 55 * Returns: %true if the vcpus are currently being throttled, %false otherwise. 56 */ 57 bool cpu_throttle_active(void); 58 59 /** 60 * cpu_throttle_get_percentage: 61 * 62 * Returns the vcpu throttle percentage. See cpu_throttle_set for details. 63 * 64 * Returns: The throttle percentage in range 1 to 99. 65 */ 66 int cpu_throttle_get_percentage(void); 67 68 #endif /* SYSEMU_CPU_THROTTLE_H */ 69