[v3,0/3] xen/sched: fix cpu hotplug

Message

Jürgen Groß Aug. 16, 2022, 10:13 a.m. UTC

A recent change in the hypervisor memory allocation framework led to
crashes when unplugging host cpus.

This was due to the (correct) assertion that allocating and freeing
memory is allowed with enabled interrupts only. As the main cpu unplug
operation is done in stop-machine context, this assertion triggers in
debug builds.

Correct that by pre-allocating all needed memory while interrupts are
still on, and free memory after interrupts are enabled again.

Changes in V3:
- addressed all comments

Changes in V2:
- addressed all comments

Juergen Gross (3):
  xen/sched: introduce cpupool_update_node_affinity()
  xen/sched: carve out memory allocation and freeing from
    schedule_cpu_rm()
  xen/sched: fix cpu hotplug

 xen/common/sched/core.c    | 214 ++++++++++++++++++++++++-------------
 xen/common/sched/cpupool.c |  91 +++++++++++-----
 xen/common/sched/private.h |  21 +++-
 xen/include/xen/sched.h    |   9 +-
 4 files changed, 235 insertions(+), 100 deletions(-)