1 /* 2 * Copyright (C) 2017 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 "src/traced/probes/ftrace/ftrace_metadata.h" 18 19 namespace perfetto { 20 21 FtraceMetadata::FtraceMetadata() { 22 // A lot of the time there will only be a small number of inodes. 23 inode_and_device.reserve(10); 24 // A sched_switch is 64 bytes, a page is 4096 bytes and we expect 25 // 2 pid's per sched_switch. 4096/64*2=128 26 pids.reserve(128); 27 // We expect to see only a small number of task rename events. 28 rename_pids.reserve(16); 29 } 30 31 void FtraceMetadata::AddDevice(BlockDeviceID device_id) { 32 last_seen_device_id = device_id; 33 #if PERFETTO_DCHECK_IS_ON() 34 seen_device_id = true; 35 #endif 36 } 37 38 void FtraceMetadata::AddInode(Inode inode_number) { 39 #if PERFETTO_DCHECK_IS_ON() 40 PERFETTO_DCHECK(seen_device_id); 41 #endif 42 static int32_t cached_pid = 0; 43 if (!cached_pid) 44 cached_pid = getpid(); 45 46 PERFETTO_DCHECK(last_seen_common_pid); 47 PERFETTO_DCHECK(cached_pid == getpid()); 48 // Ignore own scanning activity. 49 if (cached_pid != last_seen_common_pid) { 50 inode_and_device.push_back( 51 std::make_pair(inode_number, last_seen_device_id)); 52 } 53 } 54 55 void FtraceMetadata::AddCommonPid(int32_t pid) { 56 last_seen_common_pid = pid; 57 AddPid(pid); 58 } 59 60 void FtraceMetadata::AddPid(int32_t pid) { 61 // Speculative optimization aginst repated pid's while keeping 62 // faster insertion than a set. 63 if (!pids.empty() && pids.back() == pid) 64 return; 65 pids.push_back(pid); 66 } 67 68 void FtraceMetadata::AddRenamePid(int32_t pid) { 69 rename_pids.push_back(pid); 70 } 71 72 void FtraceMetadata::FinishEvent() { 73 last_seen_device_id = 0; 74 #if PERFETTO_DCHECK_IS_ON() 75 seen_device_id = false; 76 #endif 77 last_seen_common_pid = 0; 78 } 79 80 void FtraceMetadata::Clear() { 81 inode_and_device.clear(); 82 pids.clear(); 83 rename_pids.clear(); 84 overwrite_count = 0; 85 FinishEvent(); 86 } 87 88 } // namespace perfetto 89
