[LU-10257] vvp_lock, lov_page, and lovsub_{lock,page} are (more or less) unused

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.11.0
• Severity: 3
• Assignee: John Hammond
• Reporter: John Hammond

Description

struct vvp_lock, lovsub_lock and lovsub_page can be removed. Nothing happens if these layers are omitted from the corresponding cl_lock or cl_page object. If lps_index is moved to cl_page (which makes some sense based on how it's used) then lov_page can be similarly removed.

Removing struct lov_page and lovsub_page reduces the size of a cl_page object from 448 to 344 bytes on x86_64 and puts us in shouting distance from using slab-256 for cl_pages.

Issue Links

• is related to: LU-13134 try to use slab allocation for cl_page
• is related to: LU-5880 CLIO Simplification
• is related to: LU-9679 Prepare lustre for adoption into the linux kernel
• is related to: LU-10994 remove unused page layers