1 // Copyright (C) 2015 The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include <linux/taskstats.h>
16 #include <netlink/socket.h>
17 #include <netlink/genl/ctrl.h>
18 #include <netlink/genl/genl.h>
19
20 #include <algorithm>
21 #include <memory>
22
23 #include <android-base/logging.h>
24
25 #include "taskstats.h"
26
TaskstatsSocket()27 TaskstatsSocket::TaskstatsSocket()
28 : nl_(nullptr, nl_socket_free), family_id_(0) {
29 }
30
Open()31 bool TaskstatsSocket::Open() {
32 std::unique_ptr<nl_sock, decltype(&nl_socket_free)> nl(
33 nl_socket_alloc(), nl_socket_free);
34 if (!nl.get()) {
35 LOG(FATAL) << "Failed to allocate netlink socket";
36 }
37
38 int ret = genl_connect(nl.get());
39 if (ret < 0) {
40 LOG(FATAL) << nl_geterror(ret) << std::endl << "Unable to open netlink socket (are you root?)";
41 }
42
43 int family_id = genl_ctrl_resolve(nl.get(), TASKSTATS_GENL_NAME);
44 if (family_id < 0) {
45 LOG(FATAL) << nl_geterror(family_id) << std::endl << "Unable to determine taskstats family id (does your kernel support taskstats?)";
46 }
47
48 nl_ = std::move(nl);
49 family_id_ = family_id;
50
51 return true;
52 }
53
Close()54 void TaskstatsSocket::Close() {
55 nl_.reset();
56 }
57
58 struct TaskStatsRequest {
59 pid_t requested_pid;
60 taskstats stats;
61 };
62
ParseAggregateTaskStats(nlattr * attr,int attr_size,taskstats * stats)63 static pid_t ParseAggregateTaskStats(nlattr* attr, int attr_size,
64 taskstats* stats) {
65 pid_t received_pid = -1;
66 nla_for_each_attr(attr, attr, attr_size, attr_size) {
67 switch (nla_type(attr)) {
68 case TASKSTATS_TYPE_PID:
69 case TASKSTATS_TYPE_TGID:
70 received_pid = nla_get_u32(attr);
71 break;
72 case TASKSTATS_TYPE_STATS:
73 {
74 int len = static_cast<int>(sizeof(*stats));
75 len = std::min(len, nla_len(attr));
76 nla_memcpy(stats, attr, len);
77 return received_pid;
78 }
79 default:
80 LOG(ERROR) << "unexpected attribute inside AGGR";
81 return -1;
82 }
83 }
84
85 return -1;
86 }
87
ParseTaskStats(nl_msg * msg,void * arg)88 static int ParseTaskStats(nl_msg* msg, void* arg) {
89 TaskStatsRequest* taskstats_request = static_cast<TaskStatsRequest*>(arg);
90 genlmsghdr* gnlh = static_cast<genlmsghdr*>(nlmsg_data(nlmsg_hdr(msg)));
91 nlattr* attr = genlmsg_attrdata(gnlh, 0);
92 int remaining = genlmsg_attrlen(gnlh, 0);
93
94 nla_for_each_attr(attr, attr, remaining, remaining) {
95 switch (nla_type(attr)) {
96 case TASKSTATS_TYPE_AGGR_PID:
97 case TASKSTATS_TYPE_AGGR_TGID:
98 {
99 nlattr* nested_attr = static_cast<nlattr*>(nla_data(attr));
100 taskstats stats;
101 pid_t ret;
102
103 ret = ParseAggregateTaskStats(nested_attr, nla_len(attr), &stats);
104 if (ret < 0) {
105 LOG(ERROR) << "Bad AGGR_PID contents";
106 } else if (ret == taskstats_request->requested_pid) {
107 taskstats_request->stats = stats;
108 } else {
109 LOG(WARNING) << "got taskstats for unexpected pid " << ret <<
110 " (expected " << taskstats_request->requested_pid << ", continuing...";
111 }
112 break;
113 }
114 case TASKSTATS_TYPE_NULL:
115 break;
116 default:
117 LOG(ERROR) << "unexpected attribute in taskstats";
118 }
119 }
120 return NL_OK;
121 }
122
GetStats(int pid,int type,TaskStatistics & stats)123 bool TaskstatsSocket::GetStats(int pid, int type, TaskStatistics& stats) {
124 TaskStatsRequest taskstats_request = TaskStatsRequest();
125 taskstats_request.requested_pid = pid;
126
127 std::unique_ptr<nl_msg, decltype(&nlmsg_free)> message(nlmsg_alloc(),
128 nlmsg_free);
129
130 genlmsg_put(message.get(), NL_AUTO_PID, NL_AUTO_SEQ, family_id_, 0, 0,
131 TASKSTATS_CMD_GET, TASKSTATS_VERSION);
132 nla_put_u32(message.get(), type, pid);
133
134 int result = nl_send_auto_complete(nl_.get(), message.get());
135 if (result < 0) {
136 return false;
137 }
138
139 std::unique_ptr<nl_cb, decltype(&nl_cb_put)> callbacks(
140 nl_cb_alloc(NL_CB_DEFAULT), nl_cb_put);
141 nl_cb_set(callbacks.get(), NL_CB_VALID, NL_CB_CUSTOM, &ParseTaskStats,
142 static_cast<void*>(&taskstats_request));
143
144 result = nl_recvmsgs(nl_.get(), callbacks.get());
145 if (result < 0) {
146 return false;
147 }
148 nl_wait_for_ack(nl_.get());
149
150 stats = TaskStatistics(taskstats_request.stats);
151
152 return true;
153 }
154
GetPidStats(int pid,TaskStatistics & stats)155 bool TaskstatsSocket::GetPidStats(int pid, TaskStatistics& stats) {
156 return GetStats(pid, TASKSTATS_CMD_ATTR_PID, stats);
157 }
158
GetTgidStats(int tgid,TaskStatistics & stats)159 bool TaskstatsSocket::GetTgidStats(int tgid, TaskStatistics& stats) {
160 bool ret = GetStats(tgid, TASKSTATS_CMD_ATTR_TGID, stats);
161 if (ret) {
162 stats.set_pid(tgid);
163 }
164 return ret;
165 }
166
TaskStatistics(const taskstats & taskstats_stats)167 TaskStatistics::TaskStatistics(const taskstats& taskstats_stats) {
168 comm_ = std::string(taskstats_stats.ac_comm);
169 pid_ = taskstats_stats.ac_pid;
170
171 uid_ = taskstats_stats.ac_uid;
172 gid_ = taskstats_stats.ac_gid;
173 pid_ = taskstats_stats.ac_pid;
174 ppid_ = taskstats_stats.ac_ppid;
175
176 cpu_delay_count_ = taskstats_stats.cpu_count;
177 cpu_delay_ns_ = taskstats_stats.cpu_delay_total;
178
179 block_io_delay_count_ = taskstats_stats.blkio_count;
180 block_io_delay_ns_ = taskstats_stats.blkio_delay_total;
181
182 swap_in_delay_count_ = taskstats_stats.swapin_count;
183 swap_in_delay_ns_ = taskstats_stats.swapin_delay_total;
184
185 reclaim_delay_count_ = taskstats_stats.freepages_count;
186 reclaim_delay_ns_ = taskstats_stats.freepages_delay_total;
187
188 total_delay_ns_ =
189 cpu_delay_ns_ + block_io_delay_ns_ + swap_in_delay_ns_ + reclaim_delay_ns_;
190
191 cpu_time_real_ = taskstats_stats.cpu_run_real_total;
192 cpu_time_virtual_ = taskstats_stats.cpu_run_virtual_total;
193
194 read_bytes_ = taskstats_stats.read_bytes;
195 write_bytes_ = taskstats_stats.write_bytes;
196 read_write_bytes_ = read_bytes_ + write_bytes_;
197 cancelled_write_bytes_ = taskstats_stats.cancelled_write_bytes;
198 threads_ = 1;
199 }
200
AddPidToTgid(const TaskStatistics & pid_statistics)201 void TaskStatistics::AddPidToTgid(const TaskStatistics& pid_statistics) {
202 // tgid statistics already contain delay values totalled across all pids
203 // only add IO statistics
204 read_bytes_ += pid_statistics.read_bytes_;
205 write_bytes_ += pid_statistics.write_bytes_;
206 read_write_bytes_ += pid_statistics.read_write_bytes_;
207 cancelled_write_bytes_ += pid_statistics.cancelled_write_bytes_;
208 if (pid_ == pid_statistics.pid_) {
209 comm_ = pid_statistics.comm_;
210 uid_ = pid_statistics.uid_;
211 gid_ = pid_statistics.pid_;
212 ppid_ = pid_statistics.ppid_;
213 } else {
214 threads_++;
215 }
216 }
217
218 // Store new statistics and return the delta from the old statistics
Update(const TaskStatistics & new_statistics)219 TaskStatistics TaskStatistics::Update(const TaskStatistics& new_statistics) {
220 TaskStatistics delta = new_statistics;
221 delta.cpu_delay_count_ -= cpu_delay_count_;
222 delta.cpu_delay_ns_ -= cpu_delay_ns_;
223 delta.block_io_delay_count_ -= block_io_delay_count_;
224 delta.block_io_delay_ns_ -= block_io_delay_ns_;
225 delta.swap_in_delay_count_ -= swap_in_delay_count_;
226 delta.swap_in_delay_ns_ -= swap_in_delay_ns_;
227 delta.reclaim_delay_count_ -= reclaim_delay_count_;
228 delta.reclaim_delay_ns_ -= reclaim_delay_ns_;
229 delta.total_delay_ns_ -= total_delay_ns_;
230 delta.cpu_time_real_ -= cpu_time_real_;
231 delta.cpu_time_virtual_ -= cpu_time_virtual_;
232 delta.read_bytes_ -= read_bytes_;
233 delta.write_bytes_ -= write_bytes_;
234 delta.read_write_bytes_ -= read_write_bytes_;
235 delta.cancelled_write_bytes_ -= cancelled_write_bytes_;
236 *this = new_statistics;
237 return delta;
238 }
239