rcu: Make rcutorture test for hotpluggability before offlining CPUs
authorPaul E. McKenney <paul.mckenney@linaro.org>
Sat, 3 Dec 2011 23:09:28 +0000 (15:09 -0800)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sun, 11 Dec 2011 18:32:21 +0000 (10:32 -0800)
commitf220242af98a5248209426f36d93226c3e0f2391
tree64d1f3942a505c32763a9eaf463147f72ba7a554
parent2987557f52b97f679f0c324d8f51b8d66e1f2084
rcu: Make rcutorture test for hotpluggability before offlining CPUs

The rcutorture test now can automatically exercise CPU hotplug and
collect success statistics, which can be correlated with other rcutorture
activity.  This permits rcutorture to completely exercise RCU regardless
of what sort of userspace and filesystem layout is in use.  Unfortunately,
rcutorture is happy to attempt to offline CPUs that cannot be offlined,
for example, CPU 0 in both the x86 and ARM architectures.  Although this
allows rcutorture testing to proceed normally, it confounds attempts at
error analysis due to the resulting flood of spurious CPU-hotplug errors.

Therefore, this commit uses the new cpu_is_hotpluggable() function to
avoid attempting to offline CPUs that are not hotpluggable, which in
turn avoids spurious CPU-hotplug errors.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
kernel/rcutorture.c