[RFC GIT PULL rcu/next] RCU/hotplug fix

[Paul E. McKenney]

Hello, Ingo,

This pull request is for an RCU change that permits waiting for grace
periods started by CPUs late in the process of going offline.  Lack of
this capability is causing failures:

http://lkml.kernel.org/r/db9c91f6-1b17-6136-84f0-03c3c2581ab4@xxxxxxxxxxxxxx

Although these failures predate v4.12, and thus are in some sense not
regressions, it would be good for them to be fixed sooner rather than
later, hence this RFC pull request.

This commit was posted to LKML:

	http://lkml.kernel.org/r/1500933116-11642-2-git-send-email-paulmck@xxxxxxxxxxxxxxxxxx

This commit has been exposed to 0day test robot and -next testing
and is available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git for-mingo

for you to fetch changes up to a58163d8ca2c8d288ee9f95989712f98473a5ac2:

  rcu: Migrate callbacks earlier in the CPU-offline timeline (2017-07-25 13:03:43 -0700)

----------------------------------------------------------------
Paul E. McKenney (1):
      rcu: Migrate callbacks earlier in the CPU-offline timeline

 include/linux/rcupdate.h |   1 +
 kernel/cpu.c             |   1 +
 kernel/rcu/tree.c        | 209 +++++++++++++++++++++++++----------------------
 3 files changed, 115 insertions(+), 96 deletions(-)