[LU-18403] Add ldlm.namespaces.*.enable_dynamic_lru parameter

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Labels: easy
• Severity: 3
• Assignee: WC Triage
• Reporter: Andreas Dilger

Description

Originally, LDLM always had a static LRU size defined by the lru_size parameter. When dynamic LRUsizing was implemented, setting "lru_size=0" was taken as "change to dynamic LEU sizing".

For historic reasons, reading from lru_size returns the number of locks currently in the LRU for that lock namespace. This usage to fetch the current lock count was replaced long ago by the "lock_count" parameter (similar to the "resource_count parameter, unless there are multiple DLM locks on a single object (eg. read locks, non-overlapping write locks, etc.).

Any usage of "lru_size" in the test scripts to get the current lock count should be replaced by "lock_count". A second patch should be made to return the actual setting of lru_size (including zero), not the current lock count in case of dynamic lru size.