EROFS Lands Big Optimization In Linux 6.8 For Low-Memory Scenarios

Merged overnight for Linux 6.8 is enhancing the EROFS read-only open-source file-system to perform better in low-memory scenarios. Not just better, but significantly better performance.

This optimization that is now in Linux Git ahead of Linux 6.8-rc3 this coming weekend is to relax the temporary buffers allocation on readahead. Chunhai Guo with smartphone maker VIVO explained of this improvement in the patch:

"Even with inplace decompression, sometimes very few temporary buffers are still needed for a single decompression shot (e.g. 16 pages for 64k sliding window or 4 pages for 16k sliding window). In low-memory scenarios, it would be better to try to allocate with GFP_NOWAIT on readahead first. That can help reduce the time spent on page allocation under durative memory pressure."

On an Android 8-core device with 8GB of memory, when carrying out a multi-app launch benchmark, this patch yielded around a 20% improvement for app launch times with EROFS:

This optimization for the EROFS temporary buffer allocation for low-memory scenarios has been merged for Linux 6.8. This is important with EROFS beginning to appear on many (memory constrained) Android devices as well as this read-only file-system finding increasing use within the container space.