[v3,0/4] xen/sched: use new idle scheduler for free cpus

Message

Jürgen Groß Sept. 9, 2019, 9:33 a.m. UTC

These three patches have been carved out from my core scheduling series
as they are sufficiently independent to be applied even without the big
series.

Without this little series there are messages like the following to be
seen on the console when booting with smt=0:

(XEN) Adding cpu 1 to runqueue 0
(XEN) CPU 1 still not dead...
(XEN) CPU 1 still not dead...
(XEN) CPU 1 still not dead...
(XEN) CPU 1 still not dead...

By assigning cpus to Cpupool-0 only after all cpus are up and by not
using the more complicated credit2 scheduler for cpus not in any
cpupool this situation can simply no longer happen, as parking the not
to be started threads is done before.

Changes in V3:
- use ZERO_BLOCK_PTR (Patch 3)
- add patch 4

Changes in V2:
- commit messages updated
- renamed functions (Patch 2)

Juergen Gross (4):
  xen/sched: populate cpupool0 only after all cpus are up
  xen/sched: remove cpu from pool0 before removing it
  xen/sched: add minimalistic idle scheduler for free cpus
  xen/sched: switch to debugtrace in cpupool handling

 xen/common/cpupool.c       | 228 +++++++++++++++++++++++++++------------------
 xen/common/sched_credit.c  |   9 --
 xen/common/sched_null.c    |   7 --
 xen/common/schedule.c      | 172 +++++++++++++++++-----------------
 xen/include/xen/sched-if.h |   2 +
 5 files changed, 229 insertions(+), 189 deletions(-)