rcutorture: Add callback-flood test
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 19 Aug 2014 04:12:17 +0000 (21:12 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sun, 7 Sep 2014 23:24:48 +0000 (16:24 -0700)
commit38706bc5a29a73645e512c06ffb759fb56259d83
tree1bdc7a71e1f1b0b7be46c139c2673bb05dd90cb4
parenteea203fea3484598280a07fe503e025e886297fb
rcutorture: Add callback-flood test

Although RCU is designed to handle arbitrary floods of callbacks, this
capability is not routinely tested.   This commit therefore adds a
cbflood capability in which kthreads repeatedly registers large numbers
of callbacks.  One such kthread is created for each four CPUs (rounding
up), and the test may be controlled by several cbflood_* kernel boot
parameters, which control the number of bursts per flood, the number
of callbacks per burst, the time between bursts, and the time between
floods.  The default values are large enough to exercise RCU's emergency
responses to callback flooding.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David Miller <davem@davemloft.net>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Documentation/kernel-parameters.txt
kernel/rcu/rcutorture.c