---
- branch: MAIN
  date: Sat Dec  2 17:29:55 UTC 2017
  files:
  - new: '1.101'
    old: '1.100'
    path: src/sys/kern/vfs_wapbl.c
    pathrev: src/sys/kern/vfs_wapbl.c@1.101
    type: modified
  id: 20171202T172955Z.831f39377842ee1a0602520371f557ebf4697edd
  log: |
    according to benchmark extracting pkgsrc.tar, using FUA and hence waiting
    for each transfer to write through to the medium is way slower than just
    letting the drive use a cached write and doing DIOCCACHESYNC on the end

    Results were (fs block 32KB / frag 4KB, partition aligned on 32KB boundary):
    HDD at siisata(4):  no-FUA: 108 sec w/FUA: 294 sec
    SSD at ahcisata(4): no-FUA:  73 sec w/FUA: 502 sec

    change the flag so that FUA is only used for the commit block write;
    for journal data write, only pass DPO, rely on the cache flush to get them
    to media
  module: src
  subject: 'CVS commit: src/sys/kern'
  unixtime: '1512235795'
  user: jdolecek