tree e51eeb51ce73d068e9c5386e0f296ff8554ce97c
parent f1387d770527b11c5467ed6b6b3d9c3e5aa12dd4
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1484525529 -0800
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1492010620 -0700

doc: Add mid-boot operation to expedited grace periods

This commit adds a description of how expedited grace periods operate
during the mid-boot "dead zone", which starts when the scheduler spawns
the first kthread and ends when all of RCU's kthreads have been spawned.
In short, before mid-boot, synchronous grace periods can be a no-op.
After the end of mid-boot, workqueues may be used.  During mid-boot,
the requesting task drivees the expedited grace period.

For more detail, see https://lwn.net/Articles/716148/.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>