Hey there,
a recurring issue in the libdwfl integration of perf and perfparser are
supposedly overlapping modules. The perf data file contains the exact mappings
for all files corresponding to the actual mmap events that occurred during
runtime, e.g.:
```
$ perf script --show-mmap-events | gre
If possible use process_vm_readv to read 4K blocks instead of fetching
each word individually with ptrace. For unwinding this often means we
only have to do one process_vm_readv of the stack instead of dozens of
ptrace calls. There is one 4K cache per process, cleared whenever a
thread is detached.
