Question on Module Splitting with pthreads

[shinji-TH]

From the documentation on Module Splitting link

When performing module splitting with multi-threaded apps, the flags "--in-memory" and "-sGLOBAL_BASE=N" are recommanded to use in order to capture profile information from all the threads.

However, in the function do_split_module(), the flag "--in-memory" is not included when the pthread is used when building the instrument version.

Is there any particular reason why the "--in-memory" flag is not included?

[kripken]

Looks like this might not be done automatically yet. @tlively ?

[tlively]

Right. The usability story for this hasn't been quite fleshed out yet. We could pass --in-memory automatically when we are linking a multithreaded application, but we would also need to either generate or validate a reasonable value for GLOBAL_BASE. In the long run (i.e. later this year, hopefully), the usability story will be significantly simplified by using multi-memory for instrumentation, avoiding the need to set GLOBAL_BASE. Until then, users can re-instrument the original module with the --in-memory flag manually.

cc @ashleynh