So it's OK for a segment to be in a bin that suggests that it has more consecutive free pages than it really does. But it's NOT ok for a segment to be in a bin that suggests it has fewer consecutive pages than it really does. If dsa_free() is putting things back into the wrong place, that's what we need to fix.
I'm trying to move segments into appropriate bins in dsa_free().
In 0001-Re-bin-segment-when-dsa-memory-is-freed.patch, I extract
the re-bin segment logic into a separate function called rebin_segment,
call it to move the segment to the appropriate bin when dsa memory is freed. Otherwise, when allocating memory, due to the segment with enough contiguous pages is in a smaller bin, a suitable segment may not be found to allocate memory.
Fot test, I port the test_dsa patch from [1] and add an OOM case to
test memory allocation until OOM, free and then allocation, compare
