[libvirt] [PATCH v3 0/2] Fix detection of slow guest shutdown

[Christian Ehrhardt]

Hi,
after a good discussion a few days ago in
 https://www.redhat.com/archives/libvir-list/2018-August/msg00122.html
and a short lived but back then untested v2 in
 https://www.redhat.com/archives/libvir-list/2018-August/msg00199.html
I finally get access to the right HW again and completed the series.

Being finally retested and working I finally feel safe to submit without
a RFC prefix. I think this would be a great addition for a better handling
of guests with plenty of host devices passed through.

With the new code in place I can shutdown systems that have 12, 16 or
even more hostdevs attached without getting into the "zombie" mode where
libvirt will forever consider the guest as "in shutdown" as it gave up
waiting too early because the signal zero still was able to reach it.

Scaling examples (extracted with gdb):
16 Devices: virProcessKillPainfullyDelay (pid=67096, force=true, extradelay=32)
12 Devices: virProcessKillPainfullyDelay (pid=68251, force=true, extradelay=24)

*Updates in v3*
- fixup some issues found in testing and code checks

*Updates in v2*
- removed the "accept the lack of /proc/<pid> as valid process removal"
  approach due to valid concerns about reusing ressources.
- added a dynamic extra wait scaling with the amount of hostdevs

Christian Ehrhardt (2):
  process: wait longer on kill per assigned Hostdev
  process: wait longer 5->30s on hard shutdown

 src/libvirt_private.syms |  1 +
 src/qemu/qemu_process.c  |  5 +++--
 src/util/virprocess.c    | 20 ++++++++++++++++----
 src/util/virprocess.h    |  1 +
 4 files changed, 21 insertions(+), 6 deletions(-)

-- 
2.17.1