---
- branch: MAIN
  date: Tue Apr 21 13:56:18 UTC 2020
  files:
  - new: '1.86'
    old: '1.85'
    path: src/sys/arch/xen/xen/xbdback_xenbus.c
    pathrev: src/sys/arch/xen/xen/xbdback_xenbus.c@1.86
    type: modified
  id: 20200421T135618Z.fce6a2aa7999355a526541e4c27e3e7da98123dc
  log: |
    add support for indirect segments, which makes it possible to pass
    up to MAXPHYS (implementation limit, interface allows more) using
    single request

    request using indirect segment requires 1 extra copy hypercall per
    request, but saves 2 shared memory hypercalls (map_grant/unmap_grant),
    so should be net performance boost due to less TLB flushing

    this also effectively doubles disk queue size for xbd(4)
  module: src
  subject: 'CVS commit: src/sys/arch/xen/xen'
  unixtime: '1587477378'
  user: jdolecek