Hello,

Following series aims to solve two problems we have observed with the
RCU subsystem, complete details on patch 2.

The series is basically a re-write (and IMO simplification) of the RCU
logic, patch 2 containing most of the newly introduced logic.

It's been (slightly) tested locally and on the safety CI.  Maybe I'm
being naive, but this looks much easier to reason about and maintain
than the current logic.

This "simplification" is only possible after the introduction of
rcu_read_{lock,unlock}() helpers that identify RCU critical sections.

Thanks, Roger.

Roger Pau Monne (3):
  xen/rcu: introduce the concept of RCU epoch
  xen/rcu: simplify RCU implementation
  xen/rcu: remove rcu_quiesce_{disable,enable}()

 xen/common/rcupdate.c      | 497 +++++++++++--------------------------
 xen/common/softirq.c       |   4 +-
 xen/include/xen/rcupdate.h |  45 ++--
 3 files changed, 168 insertions(+), 378 deletions(-)

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2.55.0