atrace file failed to load

[barnett-yuxiang]

Has been around for a while，perfetto can not load file captured by atrace cmd:

adb shell atrace freq idle disk memory network -o /sdcard/atrace.data
adb pull /sdcard/atrace.data .

https://ui.perfetto.dev/#!/ => open file

atrace.data.zip

I debug it, seems like something wrong with zlib

[barnett-yuxiang]

@willnorris @mspang @nico @fmayer

Hi, can anyone help me?

[chromy]

Your file begins as follows:

TRACE:
# tracer: nop
#
# entries-in-buffer/entries-written: 41390/41390   #P:8
#
#                                      _-----=> irqs-off
#                                     / _----=> need-resched
#                                    | / _---=> hardirq/softirq
#                                    || / _--=> preempt-depth
#                                    ||| /     delay
#           TASK-PID    TGID   CPU#  ||||    TIMESTAMP  FUNCTION
#              | |        |      |   ||||       |         |
          <idle>-0     (-----) [002] .n.1 223230.807255: cpu_idle: state=4294967295 cpu_id=2
          <idle>-0     (-----) [004] ...1 223230.807282: cpu_idle: state=4294967295 cpu_id=4
          <idle>-0     (-----) [004] d..1 223230.807289: cpu_idle: state=3 cpu_id=4
          <idle>-0     (-----) [002] d..1 223230.807329: cpu_idle: state=3 cpu_id=2
          <idle>-0     (-----) [003] .n.1 223230.807422: cpu_idle: state=4294967295 cpu_id=3
          <idle>-0     (-----) [003] d..1 223230.807476: cpu_idle: state=3 cpu_id=3
          <idle>-0     (-----) [000] d..1 223230.807481: cpu_idle: state=0 cpu_id=0

The issue is the first line:

TRACE:

If you delete this the trace works fine.

The line that causes the issue is here:

perfetto/src/trace_processor/forwarding_trace_parser.cc

Line 171 in b508598

if (start.find("TRACE:") != std::string::npos)

When we see TRACE: we expect the file to be in .ctrace format, which is to say a .zip file. In fact your trace is not compressed so we should instead use the kSystraceTraceType parser. This can happen if someone manually uses atrace without the compression option -z. We should amend the trace detection logic to take this situation into account.

[barnett-yuxiang]

@chromy Many many thx~

[LalitMaganti]

Reopening to track the auto-detection in trace processor

[LalitMaganti]

This should now be fixed for real!