Tiny RCU's job is to be tiny, so this commit removes its RCU CPU
stall warning code.  After this, there is no longer any need for
rcu_sched_ctrlblk and rcu_bh_ctrlblk to be in tiny_plugin.h, so this
commit also moves them to tiny.c.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and
CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and
are redundant with the rcu_nocbs= boot parameter.  This commit therefore
removes these three Kconfig options and adjusts the rcutorture scripts
to use the boot parameter instead.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

RCU's debugfs tracing used to be the only reasonable low-level debug
information available, but ftrace and event tracing has since surpassed
the RCU debugfs level of usefulness.  This commit therefore removes
RCU's debugfs tracing.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Classic SRCU was only ever intended to be a fallback in case of issues
with Tree/Tiny SRCU, and the latter two are doing quite well in testing.
This commit therefore removes Classic SRCU.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The sparse-based checking for non-RCU accesses to RCU-protected pointers
has been around for a very long time, and it is now the only type of
sparse-based checking that is optional.  This commit therefore makes
it unconditional.
Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>

The PROVE_RCU_REPEATEDLY Kconfig option was initially added due to
the volume of messages from PROVE_RCU: Doing just one per boot would
have required excessive numbers of boots to locate them all.  However,
PROVE_RCU messages are now relatively rare, so there is no longer any
reason to need more than one such message per boot.  This commit therefore
removes the PROVE_RCU_REPEATEDLY Kconfig option.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>

The NO_HZ_FULL_SYSIDLE full-system-idle capability was added in 2013
by commit 0edd1b17 ("nohz_full: Add full-system-idle state machine"),
but has not been used.  This commit therefore removes it.

If it turns out to be needed later, this commit can always be reverted.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>

Anything that can be done with the RCU_KTHREAD_PRIO Kconfig option can
also be done with the rcutree.kthread_prio kernel boot parameter.
This commit therefore removes this Kconfig option.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>

The RCU_TORTURE_TEST_SLOW_PREINIT, RCU_TORTURE_TEST_SLOW_PREINIT_DELAY,
RCU_TORTURE_TEST_SLOW_PREINIT_DELAY, RCU_TORTURE_TEST_SLOW_INIT,
RCU_TORTURE_TEST_SLOW_INIT_DELAY, RCU_TORTURE_TEST_SLOW_CLEANUP,
and RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY Kconfig options are only
useful for torture testing, and there are the rcutree.gp_cleanup_delay,
rcutree.gp_init_delay, and rcutree.gp_preinit_delay kernel boot parameters
that rcutorture can use instead.  The effect of these parameters is to
artificially slow down grace period initialization and cleanup in order
to make some types of race conditions happen more often.

This commit therefore simplifies Tree RCU a bit by removing the Kconfig
options and adding the corresponding kernel parameters to rcutorture's
.boot files instead.  However, this commit also leaves out the kernel
parameters for TREE02, TREE04, and TREE07 in order to have about the
same number of tests slowed as not slowed.  TREE01, TREE03, TREE05,
and TREE06 are slowed, and the rest are not slowed.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, when running from a git archive, the testid.txt file contains
only the branch name, the output of "git status", and the SHA-1 of
the current HEAD.  This is useful, but does not uniquely identify the
source code that was built.  This commit therefore adds the output of
"git diff HEAD", which means that if two testid.txt files compare equal,
they correspond to exactly the same source code.  Give or take the
possibility of SHA-1 collisions, that is.  ;-)
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Most OS distribution have awk in /usr/bin not in /bin
Without this patch, kernel-devsrc fails to build as
runtime dependency for srcu-cbmc script /bin/awk is
not found.
Signed-off-by: NKushwaha, Priyalee <priyalee.kushwaha@intel.com>
Acked-by: NLance Roy <ldr709@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Given that the plan is to retire Classic SRCU in the near future, this
commit reduces the number of CPUs dedicated to testing Classic SRCU.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds a TINY rcuperf test scenario, which allows performance
testing of Tiny RCU and Tiny SRCU.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds a Kconfig-fragment file for Classic SRCU to ease
performance comparisons with Tree SRCU.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The TREE and TREE54 rcuperf scenarios' Kconfig fragment files specified
conflicting values for CONFIG_RCU_TRACE.  This commit therefore removes
the =n line in favor of the =y line.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

A number of the rcutorture test scenarios were not using the desired
Kconfig options because dependencies were preventing the selections in the
Kconfig-fragment files from being honored.  This commit therefore updates
the Kconfig-fragment files to account for these changes in dependencies.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The rcutorture scripting handles the CONFIG_*_TORTURE_TEST Kconfig
options specially, and therefore greps them out of the Kconfig-fragment
files.  Unfortunately, a poor choice of grep pattern means that the
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP, CONFIG_RCU_TORTURE_TEST_SLOW_INIT,
and CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT Kconfig options are also grepped
out, preventing rcutorture from using them.  This commit therefore fixes
the offending grep pattern to focus only on the CONFIG_*_TORTURE_TEST
Kconfig options.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

A robust combination of paranoia and cowardice has resulted in retaining
Classic SRCU (CONFIG_CLASSIC_SRCU) as a backup for the shiny new Tiny
and Tree SRCU implementations.  If it is to be a viable backup, it of
course needs to be tested.  This commit therefore adds an rcutorture
scenario named SRCU-C for Classic SRCU.  This commit also adds this
scenario to the set that are run by default.

Once sufficient good experience has accumulated for Tiny and Tree SRCU,
this test will be removed, along with the Classic SRCU implementation
itself.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds an SRCU-t rcutorture scenario for the new Tiny SRCU
implementation, removing the need to pass the --bootargs parameter to
kvm.sh to run Tiny SRCU tests.  This commit also adds SRCU-t to the set
of scenarios that are run by default.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Kconfig "select" clauses can defeat Kconfig-fragment file attempts to
clear a given Kconfig variable, and dependencies can defeat attempts to
set a given Kconfig variable.  Because "select" clauses and dependencies
can be added at any time, there needs to be a way to verify that the
Kconfig-fragment file's requests were honored.  And there is, except
that it is buggy.  This commit therefore provides the needed fix.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds a test for a three-level srcu_node tree for Tree SRCU
in the existing SRCU-P scenario.  This requires enabling CONFIG_RCU_EXPERT,
so the CONFIG_RCU_EXPERT=n scenario is now SRCU-N.  The reason for using
SRCU-P for the tall tree is that preemption raises the possibility of
locating more bugs than does the non-preemptive SRCU-N.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Back when SRCU was simpler, there wasn't much need for lockdep.
However, with Tree SRCU, it is needed.  This commit therefore adds
CONFIG_PROVE_LOCKING to the SRCU-P scenario.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, the rcutorture scripting will give an error message if
running a duplicate scenario that happens also to have a non-existent
build directory (b1, b2, ... in the rcutorture directory).  Worse yet, if
the build directory has already been created and used for a real build,
the script will silently grab the wrong Kconfig fragment, which could
cause confusion to the poor sap (me) analyzing old test results.  At
least the actual test runs correctly...

This commit therefore accesses the Kconfig fragment from the results
directory corresponding to the first of the duplicate scenarios, for
which a build was actually carried out.  This prevents both the messages
and at least one form of later confusion.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit creates a formal/srcu-cbmc directory containing scripts that
pull SRCU in from the source code, filter it to remove things that CBMC
cannot handle, and run a series of verifications on it.  This has a number
of shortcomings:

1.	It does not yet hook into the upper-level self-test Makefiles.
2.	It tests only a single scenario, store buffering.
3.	There is no gcc-based syntax-error prefiltering.

Nevertheless, it does fully verify a piece of SRCU under a moderately
weak memory model (PSO).
Signed-off-by: NLance Roy <ldr709@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The RCU torture tests currently do not run any Tiny RCU scenarios for
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y.  This is a hole in the test, given
that someone might need this in real life and given that Tiny RCU uses
different callback-handling code than does Tree RCU.  This commit
therefore enables this Kconfig option for scenario TINY02.
Reported-by: N"Ahmed, Iftekhar" <ahmedi@oregonstate.edu>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit runs TREE04 and TREE08 with CONFIG_RCU_EQS_DEBUG=y,
enabling dyntick-counter checking on those two tests.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit sets CONFIG_DEBUG_LOCK_ALLOC but not CONFIG_PROVE_LOCKING
for TREE08 in order to have at least one test with this configuration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit enables the CONFIG_DEBUG_OBJECTS_RCU_HEAD Kconfig option
in TREE02 in order to do at least some testing with this enabled.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit moves CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP,
CONFIG_RCU_TORTURE_TEST_SLOW_INIT, and CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT
from CFcommon to all of the TREE scenarios other than TREE08 and TREE09
in order to do at least some testing without these Kconfig options set.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit adds CONFIG_PROVE_RCU_REPEATEDLY=y, which has been untested
for quite some time.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit verifies coverage of testing with CONFIG_RCU_STALL_COMMON=n.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Although ww_mutexes degenerate into mutexes, it would be useful to
torture the deadlock handling between multiple ww_mutexes in addition to
torturing the regular mutexes.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <dev@mblankhorst.nl>
Cc: Nicolai Hähnle <nhaehnle@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161201114711.28697-3-chris@chris-wilson.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently, if the --jitter flag specifies jitter for a --build-only
run, the system will obediently build a kernel, refuse to launch it,
launch the requested number of jitter processes, and wait for the
specified kernel run time, which defaults to 30 minutes.  This is
of course quite pointless.

This commit therefore disables jitter on build-only runs.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit enables jitter by default.  It may be manually disabled
by passing "--jitter 0" to kvm.sh.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Because recent testing shows that "-soundhw pcspkr" is no longer required
in the kernel boot arguments, this commit drops this qemu argument.
Reported-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Do not restrict the cpu type to POWER7 for QEMU as we have POWER8 now.
Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The option "-soundhw pcspk" gives me a error on PPC as follow:

qemu-system-ppc64: ISA bus not available for pcspk

This means this option doesn't work on ppc by default. So simply make
this an x86-specific option via identify_qemu_args().
Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The vmlinux image is available for all the architectures, and suitable
for running a KVM guest by QEMU, besides, we used to copy the vmlinux
to $resdir anyway. Therefore it makes sense to use it as the fallback
kernel image for rcutorture KVM tests.

This patch makes identify_boot_image() return vmlinux if
${TORTURE_BOOT_IMAGE} is not set on non-x86 architectures, also fixes
several places that hard-code "bzImage" as $KERNEL.

This also fixes a problem that PPC doesn't have a bzImage file as build
results.
Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>