无法在Jelly Bean中使用systrace

Question

我试图使用果冻豆释放的新systrace,但没有运气.

我在开发设置中启用了图形和视图跟踪,例如在I/O会话上,并试图调用systrace,我得到的就是这个.

$ ./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)上尝试过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，脚本应该正确运行，尽管对我来说，html 文件仅包含每个 CPU 的行，而不包含诸如 Surface Flinger 之类的单个组件，这在 google IO 演讲视频中可见。