simpleperf: switch to unwinding while recording by default.
After speed improvements of offline unwinding, when testing
google.sample.tunnel app on marlin, the avg time unwinding a sample
is improved from 240us to 80us, while the time storing a sample with
stack data is 50us. And below are some recording test results on marlin:
unwinding after recording:
./simpleperf record -g --app com.google.sample.tunnel --duration 30 -f 1000
Samples recorded: 9677. Samples lost: 0.
./simpleperf record -g --app com.google.sample.tunnel --duration 30 -f 4000
Samples recorded: 43108. Samples lost: 101.
unwinding while recording:
./simpleperf record -g --no-post-unwind --app com.google.sample.tunnel --duration 30 -f 1000
Samples recorded: 9364. Samples lost: 80.
./simpleperf record -g --app com.google.sample.tunnel --duration 30 -f 4000 --no-post-unwind
Samples recorded: 43944. Samples lost: 1255.
The test results of unwinding after recording and unwinding while recording
are similar. So I prefer to switch to unwinding while recording by
default, because
1. Unwinding after recording takes much more temporary disk space and
post processing time, which is not suitable for long time recording.
2. We used unwinding while recording by default in ndk release and android
studio.
3. I plan to continue to reduce sample lost rate in the near future, so
the small sample lost rate differences between two methods will be
samller.
Bug: none.
Test: run simpleperf_unit_test.
Change-Id: I0addd1d56e5862360fc52ed61206e8f9c1fd4c17
3 files changed