| 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 SYSTEM_CPU_THROTTLE_H |
| 20 | #define SYSTEM_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 | /** |
| 69 | * cpu_throttle_dirty_sync_timer_tick: |
| 70 | * |
| 71 | * Dirty sync timer hook. |
| 72 | */ |
| 73 | void cpu_throttle_dirty_sync_timer_tick(void *opaque); |
| 74 | |
| 75 | /** |
| 76 | * cpu_throttle_dirty_sync_timer: |
| 77 | * |
| 78 | * Start or stop the dirty sync timer. |
| 79 | */ |
| 80 | void cpu_throttle_dirty_sync_timer(bool enable); |
| 81 | |
| 82 | #endif /* SYSTEM_CPU_THROTTLE_H */ |