1 | /* |
2 | * Copyright (c) 2015-2017 Apple Inc. All rights reserved. |
3 | * |
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27 | */ |
28 | |
29 | #ifndef _SYS_WORK_INTERVAL_H |
30 | #define _SYS_WORK_INTERVAL_H |
31 | |
32 | #include <stdint.h> |
33 | #include <sys/cdefs.h> |
34 | #include <sys/_types/_size_t.h> |
35 | |
36 | #include <mach/port.h> |
37 | |
38 | __BEGIN_DECLS |
39 | |
40 | /* |
41 | * A work interval is a repeatable unit of work characterized by a |
42 | * start, finish, and deadline. |
43 | * |
44 | * Trusted clients with deadline-sensitive work may report information |
45 | * about the execution of their work using the work interval facility. |
46 | * This is intended to be a higher-level semantic than realtime scheduling, |
47 | * which operates at the level of thread block/unblock. A high level |
48 | * operation may have many blocking points, including IPC to other tasks, |
49 | * and this this metric will capture the overall time to complete a unit of |
50 | * work. |
51 | * |
52 | * A work interval is defined by several timestamps, namely (S)tart, |
53 | * (F)inish, (D)eadline, and (N)ext start. |
54 | * |
55 | * ... ----+==================+--------+--+==== ... |
56 | * | | | | |
57 | * S F D N |
58 | * |
59 | * \__________________/ |
60 | * Active |
61 | * \___________________________/ |
62 | * Work Interval |
63 | * |
64 | * \_________/ |
65 | * | |
66 | * report information here ---------+ |
67 | * |
68 | * Definitions: |
69 | * |
70 | * Start: Absolute time when the current deadline-oriented work began. Due |
71 | * to scheduling latency, preemption, and blocking points, the |
72 | * thread controlling the work interval may actually begin |
73 | * executing after this ideal time (which may be the previous work |
74 | * interval's "next start") |
75 | * Finish: Absolute time when the current deadline-oriented work finished. |
76 | * This will typically be a timestamp taken before reporting using |
77 | * the work interval interface. |
78 | * Deadline: Absolute time by which the current work was expected to finish. |
79 | * In cases where the amount of computation (or preemption, or time |
80 | * spent blocked) causes the active period to take longer than |
81 | * expected, F may be greater than D. |
82 | * Next start: Absolute time when the next deadline-oriented work is |
83 | * expected to begin. This is typically the same as Deadline. |
84 | * Active: The fraction of the work interval spent completing the work. In |
85 | * cases where the Finish time exceeded the Deadline, this fraction |
86 | * will be >1.0. |
87 | * |
88 | * Basic Use: |
89 | * |
90 | * Clients should report information for a work interval after finishing |
91 | * work for the current interval but before the next work interval begins. |
92 | * |
93 | * If Finish far exceeds the previously expected Deadline, the |
94 | * caller may adjust Next Start to align to a multiple of the period |
95 | * (and skip over several work intervals that could not be |
96 | * executed). |
97 | * |
98 | * Caution (!): |
99 | * |
100 | * Because the information supplied via this facility directly influences power |
101 | * management decisions, clients should strive to be as accurate as possible. |
102 | * Failure to do so will adversely impact system power and performance. |
103 | * |
104 | * Work Interval Auto Join Support: |
105 | * |
106 | * Work intervals support an optional flag WORK_INTERVAL_FLAG_ENABLE_AUTO_JOIN |
107 | * which allows RT threads from the same home thread group to join work |
108 | * intervals via wakeup relationship tracking. Based on the join policy, |
109 | * RT threads can temporarily join the work interval of other RT threads |
110 | * which make them runnable. The auto joined thread remains in the work |
111 | * interval until it blocks or terminates. The mechanism works through |
112 | * make runnable heuristic and it should be used with extreme caution. |
113 | * If a client specifies this flag, it gives up explicit control over its |
114 | * thread group membership and threads unrelated to the work interval |
115 | * could become part of the thread group. This could lead to serious power |
116 | * and performance issues. If the make runnable heuristic does not work |
117 | * for a client use case, it should adopt work_interval_join_port() or |
118 | * work_interval_join() to explicitly declare its intent. |
119 | * |
120 | * Work Interval Deferred Finish Support: |
121 | * |
122 | * Another advanced feature for work intervals is the ability to defer the finish |
123 | * calls for the work interval until all auto-joined threads for the work interval |
124 | * have blocked or terminated. This feature is enabled via an optional flag |
125 | * WORK_INTERVAL_FLAG_ENABLE_DEFERRED_FINISH and is valid only if the work interval |
126 | * is configured with the WORK_INTERVAL_FLAG_ENABLE_AUTO_JOIN flag as well. The |
127 | * deferred finish mechanism allows the work interval to defer the finish call |
128 | * for the work interval until all auto-join threads have blocked/terminated |
129 | * (and have therefore un-joined the work interval) or one of the work interval |
130 | * threads calls start for the next frame. The deferred finish works only for |
131 | * workloads that have no temporal overlap across frames i.e. previous frame has to |
132 | * finish before next frame can start. This feature should be used with caution |
133 | * since auto-joined threads would delay finish calls to the performance controller |
134 | * which could lead to poor performance and battery life. |
135 | */ |
136 | |
137 | /* Flags to be passed with work_interval_create() */ |
138 | |
139 | /* If interval is joinable, create no longer implicitly joins, you must use work_interval_join */ |
140 | #define WORK_INTERVAL_FLAG_JOINABLE (0x1) |
141 | /* Only threads that join the group are measured together, otherwise the group is the creator's home group */ |
142 | #define WORK_INTERVAL_FLAG_GROUP (0x2) |
143 | /* Specifies that the work interval is being created by a client who doesn't |
144 | * necessarily have the PRIV_WORK_INTERVAL entitlement. Skip privilege checks. |
145 | * This can only be masked in for work intervals of types COREAUDIO, CA_CLIENT |
146 | * and DEFAULT */ |
147 | #define WORK_INTERVAL_FLAG_UNRESTRICTED (0x4) |
148 | |
149 | /* [Advanced Flag] Read section on "Work Interval Auto Join Support" above for details */ |
150 | #define WORK_INTERVAL_FLAG_ENABLE_AUTO_JOIN (0x8) |
151 | /* [Advanced Flag] Read section on "Work Interval Deferred Finish Support" above for details */ |
152 | #define WORK_INTERVAL_FLAG_ENABLE_DEFERRED_FINISH (0x10) |
153 | |
154 | /* Kernel-supplied flag: Work interval has been ignored by the kernel */ |
155 | #define WORK_INTERVAL_FLAG_IGNORED (0x20) |
156 | |
157 | /* Specifies that the work interval requests the system to provide just enough performance |
158 | * to be able to finish at the provided deadline and no sooner. */ |
159 | #define WORK_INTERVAL_FLAG_FINISH_AT_DEADLINE (0x40) |
160 | |
161 | /* Internal-only flag: workinterval will have the SET_WORKLOAD_ID operation called on it immediately |
162 | * after creation. */ |
163 | #define WORK_INTERVAL_FLAG_HAS_WORKLOAD_ID (0x80) |
164 | |
165 | /* Internal-only flag: Telemetry data will be aggregated from threads while they are joined to |
166 | * the work interval. */ |
167 | #define WORK_INTERVAL_FLAG_ENABLE_TELEMETRY_DATA (0x100) |
168 | |
169 | /* Flags to describe the interval flavor to the performance controller */ |
170 | #define WORK_INTERVAL_TYPE_MASK (0xF0000000) |
171 | #define WORK_INTERVAL_TYPE_DEFAULT (0x0 << 28) |
172 | #define WORK_INTERVAL_TYPE_COREAUDIO (0x1 << 28) |
173 | #define WORK_INTERVAL_TYPE_COREANIMATION (0x2 << 28) |
174 | #define WORK_INTERVAL_TYPE_CA_RENDER_SERVER (0x2 << 28) |
175 | #define WORK_INTERVAL_TYPE_CA_CLIENT (0x3 << 28) |
176 | #define WORK_INTERVAL_TYPE_HID_DELIVERY (0x4 << 28) |
177 | #define WORK_INTERVAL_TYPE_COREMEDIA (0x5 << 28) |
178 | #define WORK_INTERVAL_TYPE_ARKIT (0x6 << 28) |
179 | #define WORK_INTERVAL_TYPE_FRAME_COMPOSITOR (0x7 << 28) |
180 | #define WORK_INTERVAL_TYPE_LAST (0xF << 28) |
181 | |
182 | #ifndef KERNEL |
183 | |
184 | typedef struct work_interval *work_interval_t; |
185 | typedef struct work_interval_instance *work_interval_instance_t; |
186 | typedef struct work_interval_data *work_interval_data_t; |
187 | |
188 | /* |
189 | * Create a new work interval handle. |
190 | * |
191 | * May fail with EALREADY if the current group already has a work interval. |
192 | * |
193 | * With no flags: |
194 | * Auto-joins the work interval to the creating thread |
195 | * May only use interval_handle from creating thread |
196 | * Data provided affects native thread group |
197 | * |
198 | * With the JOINABLE flag |
199 | * interval_handle is usable by the process |
200 | * creating thread does not auto-join |
201 | * notifying thread must have joined when notifying |
202 | * |
203 | * With the GROUP flag |
204 | * creates a new thread group to isolate the joined threads from |
205 | * the rest of the process for performance controller analysis |
206 | * Threads which join the work interval become members of this new group |
207 | * |
208 | * TODO: Add a name parameter so that clients can name the work interval |
209 | * Can also take the thread name from the notifying thread |
210 | * |
211 | * Requires the 'com.apple.private.kernel.work-interval' entitlement (PRIV_WORK_INTERVAL) |
212 | * |
213 | * Note that joining a work interval supersedes automatic thread group management via vouchers |
214 | */ |
215 | int work_interval_create(work_interval_t *interval_handle, uint32_t flags); |
216 | |
217 | /* Returns the flags used for the work interval when it was created. |
218 | * |
219 | * May fail with EINVAL if the port isn't from a prior call to |
220 | * work_interval_copy_port. |
221 | */ |
222 | int work_interval_get_flags_from_port(mach_port_t port, uint32_t *flags); |
223 | |
224 | |
225 | /* |
226 | * Notify the power management subsystem that the work for a current interval has completed |
227 | * |
228 | * Only the process which created the work interval may notify |
229 | */ |
230 | int work_interval_notify(work_interval_t interval_handle, |
231 | uint64_t start, uint64_t finish, |
232 | uint64_t deadline, uint64_t next_start, |
233 | uint32_t flags); |
234 | |
235 | /* |
236 | * Notify, with "finish" implicitly set to the current time |
237 | * |
238 | * Only the process which created the work interval may notify |
239 | */ |
240 | int work_interval_notify_simple(work_interval_t interval_handle, |
241 | uint64_t start, uint64_t deadline, |
242 | uint64_t next_start); |
243 | |
244 | /* |
245 | * Deallocate work interval handle |
246 | * For non-JOINABLE, also removes thread from work interval |
247 | * For JOINABLE, does not remove thread (needs a leave as well) |
248 | */ |
249 | int work_interval_destroy(work_interval_t interval_handle); |
250 | |
251 | /* |
252 | * Join work interval via work interval handle |
253 | * Only allowed if interval is using the joinable and group flags |
254 | * |
255 | * Supersedes automatic thread group management via vouchers |
256 | */ |
257 | int work_interval_join(work_interval_t interval_handle); |
258 | |
259 | /* |
260 | * extract Mach send right representing work interval thread group |
261 | * Returns a +1 send right ref, which must be deallocated via mach_port_deallocate |
262 | * Only allowed if interval is joinable, otherwise returns ENOTSUP |
263 | * |
264 | * Supersedes automatic thread group management via vouchers |
265 | */ |
266 | int work_interval_copy_port(work_interval_t interval_handle, mach_port_t *port); |
267 | |
268 | /* |
269 | * Join work interval via Mach send right |
270 | * |
271 | * Does NOT consume Mach send right, must deallocate with mach_port_deallocate after using |
272 | * It's safe to deallocate the right after joining, the thread will stay joined |
273 | * |
274 | * Can be sent to clients via xpc_dictionary_copy_mach_send, and similar |
275 | * |
276 | * Supersedes automatic thread group management via vouchers |
277 | * |
278 | * If the underlying work interval object is terminated then this may return ENOENT |
279 | * <rdar://problem/31819320> |
280 | */ |
281 | int work_interval_join_port(mach_port_t port); |
282 | |
283 | /* |
284 | * Leave the current thread's work interval |
285 | */ |
286 | int work_interval_leave(void); |
287 | |
288 | #endif /* !KERNEL */ |
289 | |
290 | |
291 | #if PRIVATE |
292 | |
293 | /* Private interface between Libsyscall and xnu */ |
294 | #define WORK_INTERVAL_OPERATION_CREATE 0x00000001 /* deprecated */ |
295 | #define WORK_INTERVAL_OPERATION_DESTROY 0x00000002 /* arg is NULL */ |
296 | #define WORK_INTERVAL_OPERATION_NOTIFY 0x00000003 /* arg is a work_interval_notification_t */ |
297 | #define WORK_INTERVAL_OPERATION_CREATE2 0x00000004 /* arg is a work_interval_create_params */ |
298 | #define WORK_INTERVAL_OPERATION_JOIN 0x00000005 /* arg is a port_name */ |
299 | #define WORK_INTERVAL_OPERATION_GET_FLAGS 0x00000009 /* arg is a port name */ |
300 | #define WORK_INTERVAL_OPERATION_SET_NAME 0x0000000a /* arg is name string (char[WORK_INTERVAL_NAME_MAX])*/ |
301 | #define WORK_INTERVAL_OPERATION_SET_WORKLOAD_ID 0x0000000b /* arg is a work_interval_workload_id_params */ |
302 | #define WORK_INTERVAL_NAME_MAX 32 |
303 | #define WORK_INTERVAL_WORKLOAD_ID_NAME_MAX 64 |
304 | |
305 | /* Flags passed in work_interval_workload_id_params wlidp_flags field */ |
306 | #define WORK_INTERVAL_WORKLOAD_ID_HAS_ID (1u << 0) |
307 | #define WORK_INTERVAL_WORKLOAD_ID_RT_ALLOWED (1u << 1) |
308 | #define WORK_INTERVAL_WORKLOAD_ID_RT_CRITICAL (1u << 2) |
309 | |
310 | /* Flags allowed to be passed in from userspace as part of kern_work_interval_set_workload_id() */ |
311 | #define WORK_INTERVAL_SET_WORKLOAD_ID_FLAGS_MASK (WORK_INTERVAL_WORKLOAD_ID_RT_CRITICAL | WORK_INTERVAL_WORKLOAD_ID_RT_ALLOWED) |
312 | |
313 | #ifdef XNU_KERNEL_PRIVATE |
314 | |
315 | /* Marker that workinterval was joined before workload ID was set */ |
316 | #define WORK_INTERVAL_WORKLOAD_ID_ALREADY_JOINED (1u << 31) |
317 | /* Work interval is allowed to provide complexity values per frame as part of {start, update, finish} calls */ |
318 | #define WORK_INTERVAL_WORKLOAD_ID_COMPLEXITY_ALLOWED (1u << 30) |
319 | |
320 | #endif /* XNU_KERNEL_PRIVATE */ |
321 | |
322 | struct work_interval_notification { |
323 | uint64_t start; |
324 | uint64_t finish; |
325 | uint64_t deadline; |
326 | uint64_t next_start; |
327 | uint32_t notify_flags; |
328 | uint32_t create_flags; |
329 | }; |
330 | typedef struct work_interval_notification *work_interval_notification_t; |
331 | |
332 | struct work_interval_create_params { |
333 | uint64_t wicp_id; /* in/out param */ |
334 | mach_port_name_t wicp_port; /* in/out param */ |
335 | uint32_t wicp_create_flags; |
336 | }; |
337 | |
338 | struct work_interval_workload_id_params { |
339 | uint32_t wlidp_flags; /* in/out param */ |
340 | uint32_t wlidp_wicreate_flags; /* in/out param */ |
341 | uint64_t wlidp_name; /* in param (pointer to char[WORK_INTERVAL_WORKLOAD_ID_NAME_MAX])*/ |
342 | uint64_t wlidp_syscall_mask[2]; /* out param (needs to fit MACH_TRAP_TABLE_COUNT + nsysent bits) */ |
343 | }; |
344 | |
345 | |
346 | int __work_interval_ctl(uint32_t operation, uint64_t work_interval_id, void *arg, size_t len); |
347 | |
348 | #endif /* PRIVATE */ |
349 | |
350 | __END_DECLS |
351 | |
352 | #endif /* _SYS_WORK_INTERVAL_H */ |
353 | |