1/*
2 * Copyright (c) 2018 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <stdint.h>
30
31#include <kern/thread.h>
32
33#include <kperf/action.h>
34#include <kperf/buffer.h>
35#include <kperf/kperf.h>
36#include <kperf/lazy.h>
37#include <kperf/sample.h>
38
39unsigned int kperf_lazy_wait_action = 0;
40unsigned int kperf_lazy_cpu_action = 0;
41uint64_t kperf_lazy_wait_time_threshold = 0;
42uint64_t kperf_lazy_cpu_time_threshold = 0;
43
44void
45kperf_lazy_reset(void)
46{
47 kperf_lazy_wait_action = 0;
48 kperf_lazy_wait_time_threshold = 0;
49 kperf_lazy_cpu_action = 0;
50 kperf_lazy_cpu_time_threshold = 0;
51 kperf_on_cpu_update();
52}
53
54void
55kperf_lazy_off_cpu(thread_t thread)
56{
57 /* try to lazily sample the CPU if the thread was pre-empted */
58 if ((thread->reason & AST_SCHEDULING) != 0) {
59 kperf_lazy_cpu_sample(thread, flags: 0, interrupt: 0);
60 }
61}
62
63void
64kperf_lazy_make_runnable(thread_t thread, bool in_interrupt)
65{
66 assert(thread->last_made_runnable_time != THREAD_NOT_RUNNABLE);
67 /* ignore threads that race to wait and in waking up */
68 if (thread->last_run_time > thread->last_made_runnable_time) {
69 return;
70 }
71
72 uint64_t wait_time = thread_get_last_wait_duration(thread);
73 if (wait_time > kperf_lazy_wait_time_threshold) {
74 BUF_DATA(PERF_LZ_MKRUNNABLE, (uintptr_t)thread_tid(thread),
75 thread->sched_pri, in_interrupt ? 1 : 0);
76 }
77}
78
79void
80kperf_lazy_wait_sample(thread_t thread, thread_continue_t continuation,
81 uintptr_t *starting_fp)
82{
83 /* ignore idle threads */
84 if (thread->last_made_runnable_time == THREAD_NOT_RUNNABLE) {
85 return;
86 }
87 /* ignore invalid made runnable times */
88 if (thread->last_made_runnable_time < thread->last_run_time) {
89 return;
90 }
91
92 /* take a sample if thread was waiting for longer than threshold */
93 uint64_t wait_time = thread_get_last_wait_duration(thread);
94 if (wait_time > kperf_lazy_wait_time_threshold) {
95 uint64_t runnable_time = timer_grab(timer: &thread->runnable_timer);
96 uint64_t running_time = recount_thread_time_mach(thread);
97
98 BUF_DATA(PERF_LZ_WAITSAMPLE, wait_time, runnable_time, running_time);
99
100 task_t task = get_threadtask(thread);
101 struct kperf_context ctx = {
102 .cur_thread = thread,
103 .cur_task = task,
104 .cur_pid = task_pid(task),
105 .trigger_type = TRIGGER_TYPE_LAZY_WAIT,
106 .starting_fp = starting_fp,
107 };
108
109 struct kperf_sample *sample = kperf_intr_sample_buffer();
110 if (!sample) {
111 return;
112 }
113
114 unsigned int flags = SAMPLE_FLAG_PEND_USER;
115 flags |= continuation ? SAMPLE_FLAG_CONTINUATION : 0;
116 flags |= !ml_at_interrupt_context() ? SAMPLE_FLAG_NON_INTERRUPT : 0;
117
118 kperf_sample(sbuf: sample, ctx: &ctx, actionid: kperf_lazy_wait_action, sample_flags: flags);
119 }
120}
121
122void
123kperf_lazy_cpu_sample(thread_t thread, unsigned int flags, bool interrupt)
124{
125 assert(ml_get_interrupts_enabled() == FALSE);
126 if (!thread) {
127 thread = current_thread();
128 }
129
130 /* take a sample if this CPU's last sample time is beyond the threshold */
131 processor_t processor = current_processor();
132#if __arm__ || __arm64__
133 uint64_t time_now = ml_get_speculative_timebase();
134#else // __arm__ || __arm64__
135 uint64_t time_now = mach_absolute_time();
136#endif // !__arm__ && !__arm64__
137
138 uint64_t since_last_sample = time_now - processor->kperf_last_sample_time;
139 if (since_last_sample > kperf_lazy_cpu_time_threshold) {
140 processor->kperf_last_sample_time = time_now;
141 uint64_t runnable_time = timer_grab(timer: &thread->runnable_timer);
142 uint64_t running_time = recount_thread_time_mach(thread);
143
144 BUF_DATA(PERF_LZ_CPUSAMPLE, running_time, runnable_time,
145 thread->sched_pri, interrupt ? 1 : 0);
146
147 task_t task = get_threadtask(thread);
148 struct kperf_context ctx = {
149 .cur_thread = thread,
150 .cur_task = task,
151 .cur_pid = task_pid(task),
152 .trigger_type = TRIGGER_TYPE_LAZY_CPU,
153 .starting_fp = 0,
154 };
155
156 struct kperf_sample *sample = kperf_intr_sample_buffer();
157 if (!sample) {
158 return;
159 }
160
161 kperf_sample(sbuf: sample, ctx: &ctx, actionid: kperf_lazy_cpu_action,
162 SAMPLE_FLAG_PEND_USER | flags);
163 }
164}
165
166/*
167 * Accessors for configuration.
168 */
169
170int
171kperf_lazy_get_wait_action(void)
172{
173 return kperf_lazy_wait_action;
174}
175
176int
177kperf_lazy_set_wait_action(int action_id)
178{
179 if (action_id < 0 || (unsigned int)action_id > kperf_action_get_count()) {
180 return 1;
181 }
182
183 kperf_lazy_wait_action = action_id;
184 kperf_on_cpu_update();
185 return 0;
186}
187
188uint64_t
189kperf_lazy_get_wait_time_threshold(void)
190{
191 return kperf_lazy_wait_time_threshold;
192}
193
194int
195kperf_lazy_set_wait_time_threshold(uint64_t threshold)
196{
197 kperf_lazy_wait_time_threshold = threshold;
198 return 0;
199}
200
201int
202kperf_lazy_get_cpu_action(void)
203{
204 return kperf_lazy_cpu_action;
205}
206
207int
208kperf_lazy_set_cpu_action(int action_id)
209{
210 if (action_id < 0 || (unsigned int)action_id > kperf_action_get_count()) {
211 return 1;
212 }
213
214 kperf_lazy_cpu_action = action_id;
215 return 0;
216}
217
218uint64_t
219kperf_lazy_get_cpu_time_threshold(void)
220{
221 return kperf_lazy_cpu_time_threshold;
222}
223
224int
225kperf_lazy_set_cpu_time_threshold(uint64_t threshold)
226{
227 kperf_lazy_cpu_time_threshold = threshold;
228 return 0;
229}
230