---
- branch: MAIN
  date: Sun Dec  1 15:28:20 UTC 2019
  files:
  - new: '1.7'
    old: '1.6'
    path: src/sys/sys/pslist.h
    pathrev: src/sys/sys/pslist.h@1.7
    type: modified
  - new: '1.2'
    old: '1.1'
    path: src/tests/include/sys/t_pslist.c
    pathrev: src/tests/include/sys/t_pslist.c@1.2
    type: modified
  id: 20191201T152820Z.0eba6d2c492cc6e1613f770c6d4fe5e1442c5f8c
  log: |
    Adapt <sys/pslist.h> to use atomic_load/store_*.

    Changes:

    - membar_producer();
      *p = v;

        =>

      atomic_store_release(p, v);

      (Effectively like using membar_exit instead of membar_producer,
      which is what we should have been doing all along so that stores by
      the `reader' can't affect earlier loads by the writer, such as
      KASSERT(p->refcnt == 0) in the writer and atomic_inc(&p->refcnt) in
      the reader.)

    - p = *pp;
      if (p != NULL) membar_datadep_consumer();

        =>

      p = atomic_load_consume(pp);

      (Only makes a difference on DEC Alpha.  As long as lists generally
      have at least one element, this is not likely to make a big
      difference, and keeps the code simpler and clearer.)

    No other functional change intended.  While here, annotate each
    synchronizing load and store with its counterpart in a comment.
  module: src
  subject: 'CVS commit: src'
  unixtime: '1575214100'
  user: riastradh