tree 7150c781c6250cca8911bc20e233313a277dc59a
parent 90e23b6b81a9b374d2940cb0b33935d53664509e
author Paul E. McKenney <paulmck@kernel.org> 1575503921 -0800
committer Paul E. McKenney <paulmck@kernel.org> 1582243410 -0800

rcutorture: Refrain from callback flooding during boot

Additional rcutorture aggression can result in, believe it or not,
boot times in excess of three minutes on large hyperthreaded systems.
This is long enough for rcutorture to decide to do some callback flooding,
which seems a bit excessive given that userspace cannot have started
until long after boot, and it is userspace that does the real-world
callback flooding.  Worse yet, because Tiny RCU lacks forward-progress
functionality, the looping-in-the-kernel tests can also be problematic
during early boot.

This commit therefore causes rcutorture to hold off on callback
flooding until about the time that init is spawned, and the same
for looping-in-the-kernel tests for Tiny RCU.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>