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, {"CPUSET_SP_BACKGROUND"}, true) ? 0 : -1;
50 case SP_FOREGROUND:
51 case SP_AUDIO_APP:
52 case SP_AUDIO_SYS:
53 return SetTaskProfiles(tid, {"CPUSET_SP_FOREGROUND"}, true) ? 0 : -1;
54 case SP_TOP_APP:
55 return SetTaskProfiles(tid, {"CPUSET_SP_TOP_APP"}, true) ? 0 : -1;
56 case SP_SYSTEM:
57 return SetTaskProfiles(tid, {"CPUSET_SP_SYSTEM"}, true) ? 0 : -1;
58 case SP_RESTRICTED:
59 return SetTaskProfiles(tid, {"CPUSET_SP_RESTRICTED"}, true) ? 0 : -1;
60 default:
61 break;
62 }
63
64 return 0;
65 }
66
set_sched_policy(int tid,SchedPolicy policy)67 int set_sched_policy(int tid, SchedPolicy policy) {
68 if (tid == 0) {
69 tid = GetThreadId();
70 }
71 policy = _policy(policy);
72
73 #if POLICY_DEBUG
74 char statfile[64];
75 char statline[1024];
76 char thread_name[255];
77
78 snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);
79 memset(thread_name, 0, sizeof(thread_name));
80
81 unique_fd fd(TEMP_FAILURE_RETRY(open(statfile, O_RDONLY | O_CLOEXEC)));
82 if (fd >= 0) {
83 int rc = read(fd, statline, 1023);
84 statline[rc] = 0;
85 char* p = statline;
86 char* q;
87
88 for (p = statline; *p != '('; p++)
89 ;
90 p++;
91 for (q = p; *q != ')'; q++)
92 ;
93
94 strncpy(thread_name, p, (q - p));
95 }
96 switch (policy) {
97 case SP_BACKGROUND:
98 SLOGD("vvv tid %d (%s)", tid, thread_name);
99 break;
100 case SP_FOREGROUND:
101 case SP_AUDIO_APP:
102 case SP_AUDIO_SYS:
103 case SP_TOP_APP:
104 SLOGD("^^^ tid %d (%s)", tid, thread_name);
105 break;
106 case SP_SYSTEM:
107 SLOGD("/// tid %d (%s)", tid, thread_name);
108 break;
109 case SP_RT_APP:
110 SLOGD("RT tid %d (%s)", tid, thread_name);
111 break;
112 default:
113 SLOGD("??? tid %d (%s)", tid, thread_name);
114 break;
115 }
116 #endif
117
118 switch (policy) {
119 case SP_BACKGROUND:
120 return SetTaskProfiles(tid, {"SCHED_SP_BACKGROUND"}, true) ? 0 : -1;
121 case SP_FOREGROUND:
122 case SP_AUDIO_APP:
123 case SP_AUDIO_SYS:
124 return SetTaskProfiles(tid, {"SCHED_SP_FOREGROUND"}, true) ? 0 : -1;
125 case SP_TOP_APP:
126 return SetTaskProfiles(tid, {"SCHED_SP_TOP_APP"}, true) ? 0 : -1;
127 case SP_SYSTEM:
128 return SetTaskProfiles(tid, {"SCHED_SP_SYSTEM"}, true) ? 0 : -1;
129 case SP_RT_APP:
130 return SetTaskProfiles(tid, {"SCHED_SP_RT_APP"}, true) ? 0 : -1;
131 default:
132 return SetTaskProfiles(tid, {"SCHED_SP_DEFAULT"}, true) ? 0 : -1;
133 }
134
135 return 0;
136 }
137
cpusets_enabled()138 bool cpusets_enabled() {
139 static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").IsUsable());
140 return enabled;
141 }
142
schedtune_enabled()143 static bool schedtune_enabled() {
144 return (CgroupMap::GetInstance().FindController("schedtune").IsUsable());
145 }
146
cpuctl_enabled()147 static bool cpuctl_enabled() {
148 return (CgroupMap::GetInstance().FindController("cpu").IsUsable());
149 }
150
schedboost_enabled()151 bool schedboost_enabled() {
152 static bool enabled = schedtune_enabled() || cpuctl_enabled();
153
154 return enabled;
155 }
156
getCGroupSubsys(int tid,const char * subsys,std::string & subgroup)157 static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
158 auto controller = CgroupMap::GetInstance().FindController(subsys);
159
160 if (!controller.IsUsable()) return -1;
161
162 if (!controller.GetTaskGroup(tid, &subgroup))
163 return -1;
164
165 return 0;
166 }
167
get_sched_policy_from_group(const std::string & group,SchedPolicy * policy)168 static int get_sched_policy_from_group(const std::string& group, SchedPolicy* policy) {
169 if (group.empty()) {
170 *policy = SP_FOREGROUND;
171 } else if (group == "foreground") {
172 *policy = SP_FOREGROUND;
173 } else if (group == "system-background") {
174 *policy = SP_SYSTEM;
175 } else if (group == "background") {
176 *policy = SP_BACKGROUND;
177 } else if (group == "top-app") {
178 *policy = SP_TOP_APP;
179 } else if (group == "restricted") {
180 *policy = SP_RESTRICTED;
181 } else {
182 errno = ERANGE;
183 return -1;
184 }
185 return 0;
186 }
187
get_sched_policy(int tid,SchedPolicy * policy)188 int get_sched_policy(int tid, SchedPolicy* policy) {
189 if (tid == 0) {
190 tid = GetThreadId();
191 }
192
193 std::string group;
194 if (schedboost_enabled()) {
195 if ((getCGroupSubsys(tid, "schedtune", group) < 0) &&
196 (getCGroupSubsys(tid, "cpu", group) < 0)) {
197 LOG(ERROR) << "Failed to find cpu cgroup for tid " << tid;
198 return -1;
199 }
200 // Wipe invalid group to fallback to cpuset
201 if (!group.empty()) {
202 if (get_sched_policy_from_group(group, policy) < 0) {
203 group.clear();
204 } else {
205 return 0;
206 }
207 }
208 }
209
210 if (cpusets_enabled() && getCGroupSubsys(tid, "cpuset", group) < 0) {
211 LOG(ERROR) << "Failed to find cpuset cgroup for tid " << tid;
212 return -1;
213 }
214 return get_sched_policy_from_group(group, policy);
215 }
216
217 #else
218
219 /* Stubs for non-Android targets. */
220
set_sched_policy(int,SchedPolicy)221 int set_sched_policy(int, SchedPolicy) {
222 return 0;
223 }
224
get_sched_policy(int,SchedPolicy * policy)225 int get_sched_policy(int, SchedPolicy* policy) {
226 *policy = SP_SYSTEM_DEFAULT;
227 return 0;
228 }
229
230 #endif
231
get_sched_policy_name(SchedPolicy policy)232 const char* get_sched_policy_name(SchedPolicy policy) {
233 policy = _policy(policy);
234 static const char* const kSchedPolicyNames[] = {
235 [SP_BACKGROUND] = "bg", [SP_FOREGROUND] = "fg", [SP_SYSTEM] = " ",
236 [SP_AUDIO_APP] = "aa", [SP_AUDIO_SYS] = "as", [SP_TOP_APP] = "ta",
237 [SP_RT_APP] = "rt", [SP_RESTRICTED] = "rs",
238 };
239 static_assert(arraysize(kSchedPolicyNames) == SP_CNT, "missing name");
240 if (policy < SP_BACKGROUND || policy >= SP_CNT) {
241 return nullptr;
242 }
243 return kSchedPolicyNames[policy];
244 }
245
get_cpuset_policy_profile_name(SchedPolicy policy)246 const char* get_cpuset_policy_profile_name(SchedPolicy policy) {
247 /*
248 * cpuset profile array for:
249 * SP_DEFAULT(-1), SP_BACKGROUND(0), SP_FOREGROUND(1),
250 * SP_SYSTEM(2), SP_AUDIO_APP(3), SP_AUDIO_SYS(4),
251 * SP_TOP_APP(5), SP_RT_APP(6), SP_RESTRICTED(7)
252 * index is policy + 1
253 * this need keep in sync with SchedPolicy enum
254 */
255 static constexpr const char* kCpusetProfiles[SP_CNT + 1] = {
256 "CPUSET_SP_DEFAULT", "CPUSET_SP_BACKGROUND", "CPUSET_SP_FOREGROUND",
257 "CPUSET_SP_SYSTEM", "CPUSET_SP_FOREGROUND", "CPUSET_SP_FOREGROUND",
258 "CPUSET_SP_TOP_APP", "CPUSET_SP_DEFAULT", "CPUSET_SP_RESTRICTED"};
259 if (policy < SP_DEFAULT || policy >= SP_CNT) {
260 return nullptr;
261 }
262 return kCpusetProfiles[policy + 1];
263 }
264
get_sched_policy_profile_name(SchedPolicy policy)265 const char* get_sched_policy_profile_name(SchedPolicy policy) {
266 /*
267 * sched profile array for:
268 * SP_DEFAULT(-1), SP_BACKGROUND(0), SP_FOREGROUND(1),
269 * SP_SYSTEM(2), SP_AUDIO_APP(3), SP_AUDIO_SYS(4),
270 * SP_TOP_APP(5), SP_RT_APP(6), SP_RESTRICTED(7)
271 * index is policy + 1
272 * this need keep in sync with SchedPolicy enum
273 */
274 static constexpr const char* kSchedProfiles[SP_CNT + 1] = {
275 "SCHED_SP_DEFAULT", "SCHED_SP_BACKGROUND", "SCHED_SP_FOREGROUND",
276 "SCHED_SP_SYSTEM", "SCHED_SP_FOREGROUND", "SCHED_SP_FOREGROUND",
277 "SCHED_SP_TOP_APP", "SCHED_SP_RT_APP", "SCHED_SP_DEFAULT"};
278 if (policy < SP_DEFAULT || policy >= SP_CNT) {
279 return nullptr;
280 }
281 return kSchedProfiles[policy + 1];
282 }
283