---
- branch: MAIN
  date: Thu Dec  5 18:50:41 UTC 2019
  files:
  - new: '1.19'
    old: '1.18'
    path: src/common/lib/libc/gen/radixtree.c
    pathrev: src/common/lib/libc/gen/radixtree.c@1.19
    type: modified
  id: 20191205T185041Z.192310a1d048691eedd8915e6c5eaa199ab13297
  log: |
    Delete the counter from "struct radix_tree_node", and in the one place we
    need a non-zero check, substitute with a deterministic bitwise OR of all
    values in the node.  The structure then becomes cache line aligned.

    For each node we now need only touch 2 cache lines instead of 3, which makes
    all the operations faster (measured), amortises the cost of not having a
    counter, and will avoid intra-pool-page false sharing on MP.
  module: src
  subject: 'CVS commit: src/common/lib/libc/gen'
  unixtime: '1575571841'
  user: ad