[LU-9409] Lustre small IO write performance improvement

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.11.0
• Assignee: Zhenyu Xu
• Reporter: Jinshan Xiong (Inactive)

Description

This task is going to address the problem of poor small IO write performance in Lustre.

We only talk about cached I/O here because LU-4198 has a decent solution to improve AIO + DIO for small I/O.

Also for the workload of small I/O, it assumes the pattern of I/O is highly predicated. In another word, it won't help the workload of small random I/O.

The small I/O doesn't have to be page aligned.

(detailed HLD in pogress)

Issue Links

• is related to: LU-9627 Bad small-file behaviour even when local-only and on RAM-FS
• is related to: LU-10619 Tiny writes improvement: Size + glimpse changes
• is related to: LU-1757 Short I/O support
• is related to: LU-4198 Improve IO performance when using DIRECT IO using libaio