[v3,0/8] xen: support per-cpupool scheduling granularity

Message

Jürgen Groß Dec. 9, 2020, 4:09 p.m. UTC

Support scheduling granularity per cpupool. Setting the granularity is
done via hypfs, which needed to gain dynamical entries for that
purpose.

Apart from the hypfs related additional functionality the main change
for cpupools was the support for moving a domain to a new granularity,
as this requires to modify the scheduling unit/vcpu relationship.

I have tried to do the hypfs modifications in a rather generic way in
order to be able to use the same infrastructure in other cases, too
(e.g. for per-domain entries).

The complete series has been tested by creating cpupools with different
granularities and moving busy and idle domains between those.

Changes in V3:
- Patches 1-6 and 8-11 of V2 have been committed already
- New patch 2
- Addressed all comments
- Added a data pointer to struct hypfs_dyndir

Changes in V2:
- Added several new patches, especially for some further cleanups in
  cpupool.c.
- Completely reworked the locking scheme with dynamical directories:
  locking of resources (cpupools in this series) is now done via new
  callbacks which are called when traversing the hypfs tree. This
  removes the need to add locking to each hypfs related cpupool
  function and it ensures data integrity across multiple callbacks.
- Reordered the first few patches in order to have already acked
  patches in pure cleanup patches first.
- Addressed several comments.

Juergen Gross (8):
  xen/cpupool: support moving domain between cpupools with different
    granularity
  xen/hypfs: switch write function handles to const
  xen/hypfs: add new enter() and exit() per node callbacks
  xen/hypfs: support dynamic hypfs nodes
  xen/hypfs: add support for id-based dynamic directories
  xen/cpupool: add cpupool directories
  xen/cpupool: add scheduling granularity entry to cpupool entries
  xen/cpupool: make per-cpupool sched-gran hypfs node writable

 docs/misc/hypfs-paths.pandoc   |  16 +++
 xen/common/hypfs.c             | 226 ++++++++++++++++++++++++++++++-
 xen/common/sched/core.c        | 121 ++++++++++++-----
 xen/common/sched/cpupool.c     | 240 +++++++++++++++++++++++++++++++--
 xen/include/xen/guest_access.h |   5 +
 xen/include/xen/hypfs.h        |  66 ++++++---
 6 files changed, 610 insertions(+), 64 deletions(-)