1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <processgroup/sched_policy.h>
18
19 #define LOG_TAG "SchedPolicy"
20
21 #include <errno.h>
22 #include <unistd.h>
23
24 #include <android-base/logging.h>
25 #include <android-base/threads.h>
26 #include <cgroup_map.h>
27 #include <processgroup/processgroup.h>
28
29 using android::base::GetThreadId;
30
31 /* Re-map SP_DEFAULT to the system default policy, and leave other values unchanged.
32 * Call this any place a SchedPolicy is used as an input parameter.
33 * Returns the possibly re-mapped policy.
34 */
_policy(SchedPolicy p)35 static inline SchedPolicy _policy(SchedPolicy p) {
36 return p == SP_DEFAULT ? SP_SYSTEM_DEFAULT : p;
37 }
38
39 #if defined(__ANDROID__)
40
set_cpuset_policy(int tid,SchedPolicy policy)41 int set_cpuset_policy(int tid, SchedPolicy policy) {
42 if (tid == 0) {
43 tid = GetThreadId();
44 }
45 policy = _policy(policy);
46
47 switch (policy) {
48 case SP_BACKGROUND:
49 return SetTaskProfiles(tid,
50 {"HighEnergySaving", "ProcessCapacityLow", "LowIoPriority",
51 "TimerSlackHigh"},
52 true)
53 ? 0
54 : -1;
55 case SP_FOREGROUND:
56 case SP_AUDIO_APP:
57 case SP_AUDIO_SYS:
58 return SetTaskProfiles(tid,
59 {"HighPerformance", "ProcessCapacityHigh", "HighIoPriority",
60 "TimerSlackNormal"},
61 true)
62 ? 0
63 : -1;
64 case SP_TOP_APP:
65 return SetTaskProfiles(tid,
66 {"MaxPerformance", "ProcessCapacityMax", "MaxIoPriority",
67 "TimerSlackNormal"},
68 true)
69 ? 0
70 : -1;
71 case SP_SYSTEM:
72 return SetTaskProfiles(tid, {"ServiceCapacityLow", "TimerSlackNormal"}, true) ? 0 : -1;
73 case SP_RESTRICTED:
74 return SetTaskProfiles(tid, {"ServiceCapacityRestricted", "TimerSlackNormal"}, true)
75 ? 0
76 : -1;
77 default:
78 break;
79 }
80
81 return 0;
82 }
83
set_sched_policy(int tid,SchedPolicy policy)84 int set_sched_policy(int tid, SchedPolicy policy) {
85 if (tid == 0) {
86 tid = GetThreadId();
87 }
88 policy = _policy(policy);
89
90 #if POLICY_DEBUG
91 char statfile[64];
92 char statline[1024];
93 char thread_name[255];
94
95 snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);
96 memset(thread_name, 0, sizeof(thread_name));
97
98 unique_fd fd(TEMP_FAILURE_RETRY(open(statfile, O_RDONLY | O_CLOEXEC)));
99 if (fd >= 0) {
100 int rc = read(fd, statline, 1023);
101 statline[rc] = 0;
102 char* p = statline;
103 char* q;
104
105 for (p = statline; *p != '('; p++)
106 ;
107 p++;
108 for (q = p; *q != ')'; q++)
109 ;
110
111 strncpy(thread_name, p, (q - p));
112 }
113 switch (policy) {
114 case SP_BACKGROUND:
115 SLOGD("vvv tid %d (%s)", tid, thread_name);
116 break;
117 case SP_FOREGROUND:
118 case SP_AUDIO_APP:
119 case SP_AUDIO_SYS:
120 case SP_TOP_APP:
121 SLOGD("^^^ tid %d (%s)", tid, thread_name);
122 break;
123 case SP_SYSTEM:
124 SLOGD("/// tid %d (%s)", tid, thread_name);
125 break;
126 case SP_RT_APP:
127 SLOGD("RT tid %d (%s)", tid, thread_name);
128 break;
129 default:
130 SLOGD("??? tid %d (%s)", tid, thread_name);
131 break;
132 }
133 #endif
134
135 switch (policy) {
136 case SP_BACKGROUND:
137 return SetTaskProfiles(tid, {"HighEnergySaving", "TimerSlackHigh"}, true) ? 0 : -1;
138 case SP_FOREGROUND:
139 case SP_AUDIO_APP:
140 case SP_AUDIO_SYS:
141 return SetTaskProfiles(tid, {"HighPerformance", "TimerSlackNormal"}, true) ? 0 : -1;
142 case SP_TOP_APP:
143 return SetTaskProfiles(tid, {"MaxPerformance", "TimerSlackNormal"}, true) ? 0 : -1;
144 case SP_RT_APP:
145 return SetTaskProfiles(tid, {"RealtimePerformance", "TimerSlackNormal"}, true) ? 0 : -1;
146 default:
147 return SetTaskProfiles(tid, {"TimerSlackNormal"}, true) ? 0 : -1;
148 }
149
150 return 0;
151 }
152
cpusets_enabled()153 bool cpusets_enabled() {
154 static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").IsUsable());
155 return enabled;
156 }
157
schedboost_enabled()158 bool schedboost_enabled() {
159 static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").IsUsable());
160 return enabled;
161 }
162
getCGroupSubsys(int tid,const char * subsys,std::string & subgroup)163 static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
164 auto controller = CgroupMap::GetInstance().FindController(subsys);
165
166 if (!controller.IsUsable()) return -1;
167
168 if (!controller.GetTaskGroup(tid, &subgroup)) {
169 LOG(ERROR) << "Failed to find cgroup for tid " << tid;
170 return -1;
171 }
172 return 0;
173 }
174
get_sched_policy(int tid,SchedPolicy * policy)175 int get_sched_policy(int tid, SchedPolicy* policy) {
176 if (tid == 0) {
177 tid = GetThreadId();
178 }
179
180 std::string group;
181 if (schedboost_enabled()) {
182 if (getCGroupSubsys(tid, "schedtune", group) < 0) return -1;
183 }
184 if (group.empty() && cpusets_enabled()) {
185 if (getCGroupSubsys(tid, "cpuset", group) < 0) return -1;
186 }
187
188 // TODO: replace hardcoded directories
189 if (group.empty()) {
190 *policy = SP_FOREGROUND;
191 } else if (group == "foreground") {
192 *policy = SP_FOREGROUND;
193 } else if (group == "system-background") {
194 *policy = SP_SYSTEM;
195 } else if (group == "background") {
196 *policy = SP_BACKGROUND;
197 } else if (group == "top-app") {
198 *policy = SP_TOP_APP;
199 } else if (group == "restricted") {
200 *policy = SP_RESTRICTED;
201 } else {
202 errno = ERANGE;
203 return -1;
204 }
205 return 0;
206 }
207
208 #else
209
210 /* Stubs for non-Android targets. */
211
set_sched_policy(int,SchedPolicy)212 int set_sched_policy(int, SchedPolicy) {
213 return 0;
214 }
215
get_sched_policy(int,SchedPolicy * policy)216 int get_sched_policy(int, SchedPolicy* policy) {
217 *policy = SP_SYSTEM_DEFAULT;
218 return 0;
219 }
220
221 #endif
222
get_sched_policy_name(SchedPolicy policy)223 const char* get_sched_policy_name(SchedPolicy policy) {
224 policy = _policy(policy);
225 static const char* const kSchedPolicyNames[] = {
226 [SP_BACKGROUND] = "bg", [SP_FOREGROUND] = "fg", [SP_SYSTEM] = " ",
227 [SP_AUDIO_APP] = "aa", [SP_AUDIO_SYS] = "as", [SP_TOP_APP] = "ta",
228 [SP_RT_APP] = "rt", [SP_RESTRICTED] = "rs",
229 };
230 static_assert(arraysize(kSchedPolicyNames) == SP_CNT, "missing name");
231 if (policy < SP_BACKGROUND || policy >= SP_CNT) {
232 return "error";
233 }
234 return kSchedPolicyNames[policy];
235 }
236