The CONFIG_RCU_CPU_STALL_INFO has been default-y for a couple of
releases with no complaints, so it is time to eliminate this Kconfig
option entirely, so that the long-form RCU CPU stall warnings cannot
be disabled.  This commit does just that.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit updates TREE_RCU-kconfig.txt to reflect changes in RCU's
Kconfig setup.  This commit also updates rcutorture's Kconfig fragments
to account for Kconfig parameters that are now driven directly off of
other Kconfig parameters.

The #CHECK# prefix tells the rcutorture scripts to take no action to try
to set the Kconfig parameter, but to check that it does in fact get set.
This is useful for verifying that Kconfig parameters that are supposed
to be automatically set do in fact get set to the required values.
Reported-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit causes the rcutorture scripts to force RCU_EXPERT so that
these scripts can cause rcutorture to torture RCU in the various required
configurations.  However, SRCU-P, TASKS03, and TREE09 retain !RCU_EXPERT
in order to ensure testing of the vanilla configuration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit updates rcutortures configuration-fragment files to account
for the move from the CONFIG_RCU_FANOUT_EXACT Kconfig parameter to the
new rcutree.rcu_fanout_exact= boot parameter.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Given that the combination of PREEMPT_RCU and HOTPLUG_CPU is producing the
most bugs lately, this commit swaps the TREE03 and TREE04 rcu_node-tree
geometries so that the test exercising PREEMPT_RCU and HOTPLUG_CPU has
three-level rather than two-level rcu_node trees.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The CONFIG_RCU_CPU_STALL_VERBOSE Kconfig parameter causes preemptible
RCU's CPU stall warnings to dump out any preempted tasks that are blocking
the current RCU grace period.  This information is useful, and the default
has been CONFIG_RCU_CPU_STALL_VERBOSE=y for some years.  It is therefore
time for this commit to remove this Kconfig parameter, so that future
kernel builds will always act as if CONFIG_RCU_CPU_STALL_VERBOSE=y.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The CONFIG_PROVE_RCU_DELAY Kconfig parameter doesn't appear to be very
effective at finding race conditions, so this commit removes it.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
[ paulmck: Remove definition and uses as noted by Paul Bolle. ]

This commit uses the standard software ploy of introducing another
level of indirection below the configs directory.  This allows each
torture-test suite to have its own set of Kconfig files, boot parameters,
and version-specific scripts.  Initially, we have only rcu, but lock
will follow soonish.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Currently, CONFIG_RCU_TORTURE_TEST=y is hardcoded into the
kvm-test-1-rcu.sh script and CONFIG_PRINTK_TIME=y is mentioned in each
and every configs file.  This commit creates a CFcommon file for these
two Kconfig parameters, and modifies kvm-test-1-rcu.sh to copy this new
file into the .config file during the build.  This change will allow
these scripts to operate on torture types other than just rcutorture.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The TREE_RCU test cases were first put in place many years ago, and have
been incrementally modified rather than being reworked.  This commit
therefore completes a long-overdue reworking of the TREE_RCU test cases.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>