安卓开机时间/性能优化

rc启动规则：
https://android.googlesource.com/platform/external/perfetto/+/40a2915a619414d58ec47bfa176490380f0f63ad/perfetto.rc

开机时间追踪：
https://perfetto.dev/docs/case-studies/android-boot-tracing

然后设置几个属性用于开机启动追踪

setprop persist.debug.atrace.boottrace 1
setprop persist.debug.perfetto.boottrace 1
setprop persist.traced.enable 1 

增加追踪项配置到/data/misc/perfetto-configs/boottrace.pbtxt

# https://perfetto.dev/docs/case-studies/android-boot-tracing
#
# /data/misc/perfetto-configs/boottrace.pbtxt
# setprop persist.debug.perfetto.boottrace 1

buffers {
  size_kb: 65536
  fill_policy: DISCARD
}
buffers {
  size_kb: 4096
  fill_policy: DISCARD
}
data_sources {
  config {
    name: "linux.ftrace"
    ftrace_config {
      ftrace_events: "sched/sched_process_exit"
      ftrace_events: "sched/sched_process_free"
      ftrace_events: "task/task_newtask"
      ftrace_events: "task/task_rename"
      ftrace_events: "sched/sched_switch"
      ftrace_events: "power/suspend_resume"
      ftrace_events: "sched/sched_blocked_reason"
      ftrace_events: "sched/sched_wakeup"
      ftrace_events: "sched/sched_wakeup_new"
      ftrace_events: "sched/sched_waking"
      ftrace_events: "sched/sched_process_exit"
      ftrace_events: "sched/sched_process_free"
      ftrace_events: "task/task_newtask"
      ftrace_events: "task/task_rename"
      ftrace_events: "power/cpu_frequency"
      ftrace_events: "power/cpu_idle"
      ftrace_events: "power/suspend_resume"
      ftrace_events: "ftrace/print"
      atrace_categories: "adb"
      atrace_categories: "aidl"
      atrace_categories: "am"
      atrace_categories: "audio"
      atrace_categories: "binder_driver"
      atrace_categories: "binder_lock"
      atrace_categories: "bionic"
      atrace_categories: "database"
      atrace_categories: "gfx"
      atrace_categories: "hal"
      atrace_categories: "input"
      atrace_categories: "pm"
      atrace_categories: "power"
      atrace_categories: "res"
      atrace_categories: "ss"
      atrace_categories: "view"
      atrace_categories: "wm"
      disable_generic_events: true
    }
  }
}
data_sources {
  config {
    name: "linux.process_stats"
    process_stats_config {
    }
  }
}
data_sources {
  config {
    name: "linux.sys_stats"
    sys_stats_config {
      stat_period_ms: 500
      stat_counters: STAT_CPU_TIMES
      stat_counters: STAT_FORK_COUNT
      cpufreq_period_ms: 500
    }
  }
}
duration_ms: 30000

打开 https://ui.perfetto.dev/
将安卓目录下的 /data/misc/perfetto-traces/boottrace.perfetto-trace 复制出来导入
加载数据，即可看到整个开机过程的线程资源占用分布：

点开里面分析占用时间较长的进程，
logcat --pid=xxx
查看pid对应日志

结合各部分开机时间统计
https://juejin.cn/post/7345379878240206859

logcat -b events | grep -E "boot_progress|sf_stop_bootanim|wm_boot_animation_done"

发现在boot_progress_pms_ready到boot_progress_ams_ready耗时高达30s，大大影响了安卓开机到桌面的时间。
这个结果和上面trace图表现一致，system_server在堵塞，startService MTKTVINPUT服务过程时长高达24s。

• Pivot Table时长排行
  
• 火焰图片段
  
  另外，工具不可用的时候，也可以通过logcat -d | grep "SystemService"导入表格来分析日志之间的时间间隔。

接下来就只分析该服务就可以了

logcat分析服务

匹配启动时间较长的日志正则表达式如下(匹配1000ms以上的)

##(匹配10000ms即10s以上的)
took to complete: [1-9][0-9][0-9][0-9][0-9]+ms

Also

• 配置生成 https://ui.perfetto.dev/#!/record