在 Jelly Bean 中使用 systrace 失败

Question

我尝试使用 jelly bean 版本中的新 systrace，但没有成功。

我在 I/O 会话等开发设置中启用了图形和视图跟踪，并尝试调用 systrace，我得到的只是这个。

$ ./systrace.py               
error opening /sys/kernel/debug/tracing/options/overwrite: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/sched/sched_switch/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/power/cpu_frequency/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/power/cpu_idle/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/buffer_size_kb: No such file or directory (2)
error opening /sys/kernel/debug/tracing/trace_clock: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/workqueue/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/ext4/ext4_sync_file_enter/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/ext4/ext4_sync_file_exit/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/block/block_rq_issue/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/block/block_rq_complete/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/tracing_on: No such file or directory (2)
error: unable to start trace
error opening /sys/kernel/debug/tracing/tracing_on: No such file or directory (2)
error opening /sys/kernel/debug/tracing/options/overwrite: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/sched/sched_switch/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/power/cpu_frequency/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/trace_clock: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/workqueue/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/ext4/ext4_sync_file_enter/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/ext4/ext4_sync_file_exit/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/block/block_rq_issue/enable: No such file or directory (2)
error opening /sys/kernel/debug/tracing/events/block/block_rq_complete/enable: No such file or directory (2)
unable to start tracing
error opening /sys/kernel/debug/tracing/buffer_size_kb: No such file or directory (2)
An error occured while capturing the trace.  Output file was not written.

我已经在我的 Desire Hd (ace) 上尝试了模拟器和自定义固件。有什么想法吗？

Answer 1

尝试以下命令：

adb root（不确定是否有必要）， adb shell mount -t debugfs nodev /sys/kernel/debug

在这些命令下，脚本应该可以正常运行，尽管对我来说，html 文件只包含每个 CPU 的行，而不是单个组件，例如表面抛掷器，这在 google IO 会谈视频中可见。