Hi F2FS maintainers, Sorry for the duplicate — I’m resending this because the previous message was sent in HTML format.
I’ve been looking into the DIO allocation path in f2fs, specifically when a DIO write needs to allocate new blocks (e.g., hole-filling). From f2fs_map_blocks() through __allocate_data_block() → f2fs_allocate_data_block(), it seems each block allocation is handled one-by-one, taking curseg_lock/curseg_mutex and the SIT sentry lock per block. I’m wondering whether batching allocations (a bounded batch, e.g., a small run within the current segment) could be feasible in the DIO path. My intuition is that with multiple threads doing DIO, reducing per-block lock contention and improving sequentiality could help throughput. Questions: Is there a technical or correctness reason that makes batching for DIO infeasible (e.g., LFS/SSR/GC interactions, summary/SIT update ordering, etc.)? Or is this simply an optimization that hasn’t been implemented? If this seems acceptable, would you consider patches in this direction? If there are prior discussions or known issues on this, I’d appreciate pointers. Thanks for your time. Best regards, Jeuk Kim _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
