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 <fcntl.h>
23 #include <unistd.h>
24
25 #include <android-base/logging.h>
26 #include <android-base/threads.h>
27 #include <cgroup_map.h>
28 #include <processgroup/processgroup.h>
29
30 using android::base::GetThreadId;
31
32 /* Re-map SP_DEFAULT to the system default policy, and leave other values unchanged.
33 * Call this any place a SchedPolicy is used as an input parameter.
34 * Returns the possibly re-mapped policy.
35 */
_policy(SchedPolicy p)36 static inline SchedPolicy _policy(SchedPolicy p) {
37 return p == SP_DEFAULT ? SP_SYSTEM_DEFAULT : p;
38 }
39
40 #if defined(__ANDROID__)
41
set_cpuset_policy(pid_t tid,SchedPolicy policy)42 int set_cpuset_policy(pid_t tid, SchedPolicy policy) {
43 if (tid == 0) {
44 tid = GetThreadId();
45 }
46 policy = _policy(policy);
47
48 switch (policy) {
49 case SP_BACKGROUND:
50 return SetTaskProfiles(tid, {"CPUSET_SP_BACKGROUND"}, true) ? 0 : -1;
51 case SP_FOREGROUND:
52 case SP_AUDIO_APP:
53 case SP_AUDIO_SYS:
54 return SetTaskProfiles(tid, {"CPUSET_SP_FOREGROUND"}, true) ? 0 : -1;
55 case SP_TOP_APP:
56 return SetTaskProfiles(tid, {"CPUSET_SP_TOP_APP"}, true) ? 0 : -1;
57 case SP_SYSTEM:
58 return SetTaskProfiles(tid, {"CPUSET_SP_SYSTEM"}, true) ? 0 : -1;
59 case SP_RESTRICTED:
60 return SetTaskProfiles(tid, {"CPUSET_SP_RESTRICTED"}, true) ? 0 : -1;
61 default:
62 break;
63 }
64
65 return 0;
66 }
67
set_sched_policy(pid_t tid,SchedPolicy policy)68 int set_sched_policy(pid_t tid, SchedPolicy policy) {
69 if (tid == 0) {
70 tid = GetThreadId();
71 }
72 policy = _policy(policy);
73
74 #if POLICY_DEBUG
75 char statfile[64];
76 char statline[1024];
77 char thread_name[255];
78
79 snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);
80 memset(thread_name, 0, sizeof(thread_name));
81
82 unique_fd fd(TEMP_FAILURE_RETRY(open(statfile, O_RDONLY | O_CLOEXEC)));
83 if (fd >= 0) {
84 int rc = read(fd, statline, 1023);
85 statline[rc] = 0;
86 char* p = statline;
87 char* q;
88
89 for (p = statline; *p != '('; p++)
90 ;
91 p++;
92 for (q = p; *q != ')'; q++)
93 ;
94
95 strncpy(thread_name, p, (q - p));
96 }
97 switch (policy) {
98 case SP_BACKGROUND:
99 SLOGD("vvv tid %d (%s)", tid, thread_name);
100 break;
101 case SP_FOREGROUND:
102 case SP_AUDIO_APP:
103 case SP_AUDIO_SYS:
104 case SP_TOP_APP:
105 SLOGD("^^^ tid %d (%s)", tid, thread_name);
106 break;
107 case SP_SYSTEM:
108 SLOGD("/// tid %d (%s)", tid, thread_name);
109 break;
110 case SP_RT_APP:
111 SLOGD("RT tid %d (%s)", tid, thread_name);
112 break;
113 default:
114 SLOGD("??? tid %d (%s)", tid, thread_name);
115 break;
116 }
117 #endif
118
119 switch (policy) {
120 case SP_BACKGROUND:
121 return SetTaskProfiles(tid, {"SCHED_SP_BACKGROUND"}, true) ? 0 : -1;
122 case SP_FOREGROUND:
123 case SP_AUDIO_APP:
124 case SP_AUDIO_SYS:
125 return SetTaskProfiles(tid, {"SCHED_SP_FOREGROUND"}, true) ? 0 : -1;
126 case SP_TOP_APP:
127 return SetTaskProfiles(tid, {"SCHED_SP_TOP_APP"}, true) ? 0 : -1;
128 case SP_SYSTEM:
129 return SetTaskProfiles(tid, {"SCHED_SP_SYSTEM"}, true) ? 0 : -1;
130 case SP_RT_APP:
131 return SetTaskProfiles(tid, {"SCHED_SP_RT_APP"}, true) ? 0 : -1;
132 default:
133 return SetTaskProfiles(tid, {"SCHED_SP_DEFAULT"}, true) ? 0 : -1;
134 }
135
136 return 0;
137 }
138
cpusets_enabled()139 bool cpusets_enabled() {
140 static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").IsUsable());
141 return enabled;
142 }
143
schedtune_enabled()144 static bool schedtune_enabled() {
145 return (CgroupMap::GetInstance().FindController("schedtune").IsUsable());
146 }
147
cpuctl_enabled()148 static bool cpuctl_enabled() {
149 return (CgroupMap::GetInstance().FindController("cpu").IsUsable());
150 }
151
schedboost_enabled()152 bool schedboost_enabled() {
153 static bool enabled = schedtune_enabled() || cpuctl_enabled();
154
155 return enabled;
156 }
157
getCGroupSubsys(pid_t tid,const char * subsys,std::string & subgroup)158 static int getCGroupSubsys(pid_t tid, const char* subsys, std::string& subgroup) {
159 auto controller = CgroupMap::GetInstance().FindController(subsys);
160
161 if (!controller.IsUsable()) return -1;
162
163 if (!controller.GetTaskGroup(tid, &subgroup))
164 return -1;
165
166 return 0;
167 }
168
get_sched_policy_from_group(const std::string & group,SchedPolicy * policy)169 static int get_sched_policy_from_group(const std::string& group, SchedPolicy* policy) {
170 if (group.empty()) {
171 *policy = SP_FOREGROUND;
172 } else if (group == "foreground") {
173 *policy = SP_FOREGROUND;
174 } else if (group == "system-background") {
175 *policy = SP_SYSTEM;
176 } else if (group == "background") {
177 *policy = SP_BACKGROUND;
178 } else if (group == "top-app") {
179 *policy = SP_TOP_APP;
180 } else if (group == "restricted") {
181 *policy = SP_RESTRICTED;
182 } else {
183 errno = ERANGE;
184 return -1;
185 }
186 return 0;
187 }
188
get_sched_policy(pid_t tid,SchedPolicy * policy)189 int get_sched_policy(pid_t tid, SchedPolicy* policy) {
190 if (tid == 0) {
191 tid = GetThreadId();
192 }
193
194 std::string group;
195 if (schedboost_enabled()) {
196 if ((getCGroupSubsys(tid, "schedtune", group) < 0) &&
197 (getCGroupSubsys(tid, "cpu", group) < 0)) {
198 LOG(ERROR) << "Failed to find cpu cgroup for tid " << tid;
199 return -1;
200 }
201 // Wipe invalid group to fallback to cpuset
202 if (!group.empty()) {
203 if (get_sched_policy_from_group(group, policy) < 0) {
204 group.clear();
205 } else {
206 return 0;
207 }
208 }
209 }
210
211 if (cpusets_enabled() && getCGroupSubsys(tid, "cpuset", group) < 0) {
212 LOG(ERROR) << "Failed to find cpuset cgroup for tid " << tid;
213 return -1;
214 }
215 return get_sched_policy_from_group(group, policy);
216 }
217
218 #else
219
220 /* Stubs for non-Android targets. */
221
set_sched_policy(int,SchedPolicy)222 int set_sched_policy(int, SchedPolicy) {
223 return 0;
224 }
225
get_sched_policy(int,SchedPolicy * policy)226 int get_sched_policy(int, SchedPolicy* policy) {
227 *policy = SP_SYSTEM_DEFAULT;
228 return 0;
229 }
230
231 #endif
232
get_sched_policy_name(SchedPolicy policy)233 const char* get_sched_policy_name(SchedPolicy policy) {
234 policy = _policy(policy);
235 static const char* const kSchedPolicyNames[] = {
236 [SP_BACKGROUND] = "bg", [SP_FOREGROUND] = "fg", [SP_SYSTEM] = " ",
237 [SP_AUDIO_APP] = "aa", [SP_AUDIO_SYS] = "as", [SP_TOP_APP] = "ta",
238 [SP_RT_APP] = "rt", [SP_RESTRICTED] = "rs",
239 };
240 static_assert(arraysize(kSchedPolicyNames) == SP_CNT, "missing name");
241 if (policy < SP_BACKGROUND || policy >= SP_CNT) {
242 return nullptr;
243 }
244 return kSchedPolicyNames[policy];
245 }
246
get_cpuset_policy_profile_name(SchedPolicy policy)247 const char* get_cpuset_policy_profile_name(SchedPolicy policy) {
248 /*
249 * cpuset profile array for:
250 * SP_DEFAULT(-1), SP_BACKGROUND(0), SP_FOREGROUND(1),
251 * SP_SYSTEM(2), SP_AUDIO_APP(3), SP_AUDIO_SYS(4),
252 * SP_TOP_APP(5), SP_RT_APP(6), SP_RESTRICTED(7)
253 * index is policy + 1
254 * this need keep in sync with SchedPolicy enum
255 */
256 static constexpr const char* kCpusetProfiles[SP_CNT + 1] = {
257 "CPUSET_SP_DEFAULT", "CPUSET_SP_BACKGROUND", "CPUSET_SP_FOREGROUND",
258 "CPUSET_SP_SYSTEM", "CPUSET_SP_FOREGROUND", "CPUSET_SP_FOREGROUND",
259 "CPUSET_SP_TOP_APP", "CPUSET_SP_DEFAULT", "CPUSET_SP_RESTRICTED"};
260 if (policy < SP_DEFAULT || policy >= SP_CNT) {
261 return nullptr;
262 }
263 return kCpusetProfiles[policy + 1];
264 }
265
get_sched_policy_profile_name(SchedPolicy policy)266 const char* get_sched_policy_profile_name(SchedPolicy policy) {
267 /*
268 * sched profile array for:
269 * SP_DEFAULT(-1), SP_BACKGROUND(0), SP_FOREGROUND(1),
270 * SP_SYSTEM(2), SP_AUDIO_APP(3), SP_AUDIO_SYS(4),
271 * SP_TOP_APP(5), SP_RT_APP(6), SP_RESTRICTED(7)
272 * index is policy + 1
273 * this need keep in sync with SchedPolicy enum
274 */
275 static constexpr const char* kSchedProfiles[SP_CNT + 1] = {
276 "SCHED_SP_DEFAULT", "SCHED_SP_BACKGROUND", "SCHED_SP_FOREGROUND",
277 "SCHED_SP_SYSTEM", "SCHED_SP_FOREGROUND", "SCHED_SP_FOREGROUND",
278 "SCHED_SP_TOP_APP", "SCHED_SP_RT_APP", "SCHED_SP_DEFAULT"};
279 if (policy < SP_DEFAULT || policy >= SP_CNT) {
280 return nullptr;
281 }
282 return kSchedProfiles[policy + 1];
283 }
284