[LU-13134] try to use slab allocation for cl_page

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Assignee: Wang Shilong (Inactive)
• Reporter: Wang Shilong (Inactive)

Description

Currently we use kmalloc for cl_page allocation, this is because
cl_page size could be different with different objects(normal clio, obdecho objects)

for most of cases we have 400+ bytes cl_page, kmalloc use 512 bytes slab behind, so instead of doing this behind, We just try to use private slab pool directly(512 bytes).

This make much sesne especially for Direct IO since it try to allocate/free cl_page very frequently.

Issue Links

• is related to: LU-14711 Canceling lock with a lot of cached data can take a lot of time
• is related to: LU-10257 vvp_lock, lov_page, and lovsub_{lock,page} are (more or less) unused
• is related to: LU-10994 remove unused page layers