| The code in this directory is used to process data from the mmc tracepoints |
| in the kernel. To turn on mmc tracing, do this: |
| |
| adb shell echo 1 >/d/tracing/events/mmc/enable |
| adb shell echo 1 >/d/tracing/tracing_on |
| |
| To get the trace: |
| |
| adb pull /d/tracing/trace |
| |
| To turn it back off, do: |
| |
| adb shell echo 0 >/d/tracing/tracing_enabled |
| |
| The output is in a form of start/stop pairs. The ops with rw in the name are |
| read or write ops, and the ones with erase in the name are the various erase |
| opts. |
| |
| The mmc_trace_reduce script will take the output from the kernel, and convert it |
| to a single line per event, which includes the duration of the event. |
| |
| This can then be fed into other tools for further analysis. |
| |
| The file mmc_trace_sample_data contains sample mmc trace data from a Nexus 10. |
| It includes read, write and discard entries. The discard entries came from |
| invoking fstrim in vold with "vdc fstrim dotrim". |
| |