simpleperf: use per process maps.
Originally we use per thread maps, and copy the maps from parent thread
when processing ForkRecord. But there are situations that ForkRecords
are lost, then the new thread is left having no maps, which leads to unknown
dso/symbols.
To fix this, we can use per process maps. Even if ForkRecords are lost,
we know which process a SampleRecord belongs to, and can use the process maps.
This is reasonable because in most cases, new threads in the same thread group
are created with both CLONE_THREAD and CLONE_VM.
Bug: http://b/33503165
Test: run simpleperf_unit_test.
Change-Id: If84b6cdac39cd6ad4e441ed6d75ed879b86d1830
4 files changed