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>

Using dracut is another way to get an initramfs for KVM-based RCU
torture tests, which is more flexible than using the host's initramfs
image, because modules and binaries may be added or removed via dracut
command options. So add an example in the document, in case that there
are some situations where host's initramfs couldn't be used.
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>

This commit adds a string of the form "Starves: 10" to the summary
line for error conditions found in the console output.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit avoids killing qemu if a trace dump is making progress
or if console log output is continuing and the console log timestamp
does not exceed the total plus grace period.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, the rcutorture scripts do not test boot-time adjustment of
leaf fanout (via the rcutree.rcu_fanout_leaf boot parameter), as was noted
during testing carried out by Iftekhar Ahmed of Oregon State University.
This commit therefore adjusts TREE04's CONFIG_RCU_FANOUT_LEAF from 4 to 3,
and also adds rcutree.rcu_fanout_leaf=4 to its boot parameters.  This
change forces RCU's boot-time geometry-change code to be exercised.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, if the user specifies multiple runs of a given test
configuration, the scripting does multiple kernel builds.  This wastes
both time and disk space, so this commit makes the scripting use the
first build for all runs of a given test configuration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds a --jitter OS-jitter capability to expose bugs based
on no-delay assumptions.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit converts test duration from minutes to seconds early on
in order to prepare for upcoming OS-jitter-injection changes.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The current hang-check machinery in the rcutorture scripts uses "$!" of
a parenthesized bash statement to capture the pid.  Unfortunately, this
captures not qemu's pid, but rather that of its parent that implements
the parenthesized statement.  This commit therefore adjusts things so as
to capture qemu's actual pid, which then allows the script to actually
kill qemu in event of a kernel hang.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds an rcuperf scenario named TREE54 that uses 54 CPUs and
provides a four-level rcu_node combining tree.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The rcuperf event-trace data is more accurate than are the rcuperf
printk()s because locking keeps things ordered.  This commit therefore
parses and analyzes this event-trace data if present, and falls back on
the printk()s otherwise.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit enables ftrace in the rcuperf TREE kernel build and adds
an ftrace_dump() at the end of rcuperf processing.  This data will be
used to measure the actual durations of the expedited grace periods
without the added delays inherent in the kernel-module measurements.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds a line giving the number of grace periods, the number
of batches, and the ratio.  The larger the ratio, the greater the
batching efficiency.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds the scripting changes to add support for the shiny
new rcuperf kernel module.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

The current scripts parse console output only for cases where one CPU
detect a stall on some other CPU or task.  This commit therefore adds
checks for self-detected stalls.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, an error-free run produces an empty console.log.diags file.
This can be annoying when using "vi */console.log.diags" to see a full
summary of the errors.  This commit therefore removes any empty files
during the analysis process.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This commit adds checks for rcutorture writer starvation, so that
instances will be added to the test summary.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Currently, the console output files ("console.log") are placed in the
build directory initially, then copied to the results directory.
One problem with this is if a qemu refuses to die in a timely fashion
after a kernel hang, it will continue to write after the next qemu
starts up, resulting in confusing output from the old instance of
qemu.  This commit prevents such confusion by placing the console.log
files into the results directory to begin with, so that a given instance
of qemu is always writing only to its own console.log file.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Currently, the scripts print a list of warning/bug indicators from the
console.log file.  This works well if there are only a few warnings or
bugs, but can be quite annoying if there is a large number.  This commit
therefore prints a summary listing the number of each type of warning/bug
indicator, but only if there is at least one such indicator.  The full
list is stored in the results directory at console.log.diags, which
makes it easier to find the warning/bugs in the full console.log.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Commit d1ec4c34 ("rcu: Drop RCU_USER_QS in favor of NO_HZ_FULL") has
removed RCU_USER_QS from Kconfig file, so remove it from some documents
to avoid any confusion.
Signed-off-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The default test grace period of two minutes is insufficient in some
cases and excessive in others.  This commit therefore increases the
default to three minutes, but also adds a --shutdown-grace parameter
to allow the default to be overridden.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Currently, the scripts print "----Start batch" at the beginning of each
batch, which does serve as a good visual delimiter between batches.
Unfortunately, if there are a lot of batches, it is hard to quickly
estimate test runtime from the output of "--dryrun sched".  This commit
therefore adds a batch number, so that the beginning-of-batch output
looks like this "----Start batch 10" for the tenth batch.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit allows --bootarg instead of --bootargs, --config instead of
--configs, and --qemu-arg instead of --qemu-args.  For those cases where
a native English speaker might auto-correct the argument to be incorrect.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

This commit adds percpu_rwsem tests based on the earlier rwsem tests.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

Real time mutexes is one of the few general primitives
that we do not have in locktorture. Address this -- a few
considerations:

o To spice things up, enable competing thread(s) to become
rt, such that we can stress different prio boosting paths
in the rtmutex code. Introduce a ->task_boost callback,
only used by rtmutex-torturer. Tasks will boost/deboost
around every 50k (arbitrarily) lock/unlock operations.

o Hold times are similar to what we have for other locks:
only occasionally having longer hold times (per ~200k ops).
So we roughly do two full rt boost+deboosting ops with
short hold times.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

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>

Currently none of the RCU-tasks scenarios enables lockdep-RCU, which
causes bugs to be missed.  This commit therefore enables lockdep-RCU
on TASKS01.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

Although it is currently possible to run the same test in parallel,
'--config "TINY01 TINY01 TINY01"' can get a bit verbose, especially
if you want to run 48 instances of TINY01 in parallel.  This commit
therefore allows prefixing the Kconfig fragment with a repeat count,
for example, '--config "48*TINY01"' to run 48 instances in parallel.
At least assuming that you have 48 CPUs and also gave '--cpus 48'.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

The current rcutorture scripting fails to dump out errors from
"make oldconfig", so this commit addresses this issue.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

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>

The TASKS01, TASKS02, and TASKS03 rcutorture config fragments currently
set CONFIG_TASKS_RCU.  However, now that the value of this Kconfig
parameter is set via "select" statements, it is no longer necessary to
set it explicitly.  This commit therefore removes it from the Kconfig
fragments.
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>

The current rcutorture testing does not do any cleanup operations.
This works because the srcu_struct is statically allocated, but it
does represent a memory leak of the associated dynamically allocated
->per_cpu_ref per-CPU variables.  However, rcutorture currently uses
a statically allocated srcu_struct, which cannot legally be passed to
cleanup_srcu_struct().  Therefore, this commit adds a second form
of srcu (called srcud) that dynamically allocates and frees the
associated per-CPU variables.  This commit also adds a ->cleanup()
member to rcu_torture_ops that is invoked at the end of the test,
after ->cb_barriers().  This ->cleanup() pointer is NULL for all
existing tests, and thus only used for scrud.  Finally, the SRCU-P
torture-test configuration selects scrud instead of srcu, with SRCU-N
continuing to use srcu, thereby testing both static and dynamic
srcu_struct structures.
Reported-by: N"Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>

TREE03 has been especially effective at finding bugs lately.  This commit
makes it even more effective by speeding up its CPU hotplug testing and
increasing its NR_CPUs from 8 to 16.  TREE08's NR_CPUS is decreased from
16 to 8 in order to maintain the same test duration.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.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>