Docling Parse v4 accumulating memory

[dolfim-ibm]

Bug

The Docling Parse v4 has been found to accumulate lots of memory for (very) long documents.

With the attached example, the system will use more than 20GB.

Using other PDF backend (both pypdfium2 and dlparse_v2) is converting all with a constant memory of about 3.9GB.

Document: pg4500.pdf

Steps to reproduce

docling -vv --no-ocr --image-export-mode=placeholder --pdf-backend=dlparse_v4 --to md --to json pg4500.pdf

Docling version

docling --version
Docling version: 2.44.0
Docling Core version: 2.44.1
Docling IBM Models version: 3.9.0
Docling Parse version: 4.1.0
Python: cpython-312 (3.12.9)
Platform: macOS-15.5-arm64-arm-64bit