[LU-35] Make portals_handle use the generic cfs_hash_t

• Type: Improvement
• Resolution: Incomplete
• Priority: Minor
• Fix Version/s: Lustre 2.1.0
• Affects Version/s: Lustre 2.0.0
• Assignee: John Spray (Inactive)
• Reporter: John Spray (Inactive)

Description

Despite the existence of the cfs_hash_t hash table class, the global hash table of portals_handle has its own fixed-bucket-count hash table implementation, using RCU for the lists of handles.

This issue relates to a patch to be pushed to gerrit, which will:

• Remove the RCU support from the portals_handle hash table (RCU is less portable, requires extra complexity in code using portals_handle, and makes the portals_handle struct larger)
• Convert the portals_handle hash table to be a standard cfs_hash_t (reducing code size and getting advantage of hash resizing)
• Introduce per-cpu variables for the portals_handle cookie generation to reduce contention on a global lock when allocating cookies (potentially improving SMP performance)