create_gcov crashes when perf.data file is large in size about autofdo HOT 5 CLOSED

We've not tested the perf reader with very large input, so I'm not surprised that this bug slipped our testing. Feel free to send out pull request for the fixing. It is also possible that the bug would be fixed after rebasing quipper to the latest.

A workaround would be sample for small period of time multiple times, and use sample-merger to merge these small perf.data into text format.

from autofdo.

Thanks for your reply.
So, what I understand is that I can create multiple gcovs using small many small perf.data files, and combine them into 1 gcov?
And then I can use this resulting gcov to optimize my code using autofdo (using fauto-profile).
Combing multiple gcovs seems to be a problem. I can see solutions of combining gcda and gcno files , to create one gcov. I could not find how to create merge many gcovs together.

from autofdo.

You can use profiler_merger for that purpose. OTOH, you can also use sample_merger to merge perf.data samples into text files, and then use create_llvm_prof/create_gcov with -profiler=text to take that text file as --profile, in this way you only need to symbolize the binary once.

from autofdo.

I am able to use both profile_merger and sample_merger to get around the problem of handling large perf.data files.
Thanks a lot for your help.

from autofdo.

I assume this bug is no applicable any more with the use of sample_merger/profile_merge. Closing it for now.

from autofdo.