Dont double adjust return addresses in imported simpleperf profiles #237
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The addresses in call chains in perf.data files from simpleperf have already been adjusted to point into the call instruction. This is different from what we're used to from perf.data files generated by Linux perf. The adjustment happens in two places: If the unwinding happens in the kernel, the callchains are adjusted in SampleRecord::AdjustCallChainGeneratedByKernel(): https://cs.android.com/android/platform/superproject/+/main:system/extras/simpleperf/record.cpp;l=949-982;drc=428d4a5fdb7745f73f52e930120dba9d2f215c26 If simpleperf does the unwinding of the user stack itself, the callchains are adjusted in libunwindstack, i.e in the unwinder that's used by simpleperf: https://cs.android.com/android/platform/superproject/+/main:system/unwinding/libunwindstack/Unwinder.cpp;l=177;drc=8e2c60d01e0928275d30f320c3f83ac4f29b880c https://cs.android.com/android/platform/superproject/+/main:system/unwinding/libunwindstack/Regs.cpp;l=175-224;drc=c0fa0c327e58eda604b2fd00b81f1c12817542d3
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The addresses in call chains in perf.data files from simpleperf have already been adjusted to point into the call instruction. This is different from what we're used to from perf.data files generated by Linux perf.
The adjustment happens in two places:
If the unwinding happens in the kernel, the callchains are adjusted in
SampleRecord::AdjustCallChainGeneratedByKernel().If simpleperf does the unwinding of the user stack itself, the callchains are adjusted in libunwindstack,
i.e in the unwinder that's used by simpleperf:
https://cs.android.com/android/platform/superproject/+/main:system/unwinding/libunwindstack/Unwinder.cpp;l=177;drc=8e2c60d01e0928275d30f320c3f83ac4f29b880c
https://cs.android.com/android/platform/superproject/+/main:system/unwinding/libunwindstack/Regs.cpp;l=175-224;drc=c0fa0c327e58eda604b2fd00b81f1c12817542d3