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: Paul 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: Paul 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Josh 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: "Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tiny RCU supports both RCU-sched and RCU-bh, but only RCU-sched is
currently tested by the rcutorture scripts. This commit therefore
changes the TINY02 configuration to test RCU-bh, with TINY01 continuing
to test RCU-sched.
This shortcoming of the current rcutorture tests was located by mutation
testing by Iftekhar. The idea behind mutation testing is to automatically
mutate the code under test. If a given mutant is not caught by testing,
this is a hint that the testing might need to be improved, as was the
case here. Note that this is only a hint because it is possible to mutate
the code into something else that still works. For example, a mutation
that removes (say) a WARN_ON() will not normally result in a test failure.
This change resulted in the test failure caused by list mishandling,
which is fixed by the next commit.
Reported-by: "Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Grace-period scans of the rcu_node combining tree normally
proceed quite quickly, so that it is very difficult to reproduce
races against them. This commit therefore allows grace-period
pre-initialization and cleanup to be artificially slowed down,
increasing race-reproduction probability. A pair of pairs of new
Kconfig parameters are provided, RCU_TORTURE_TEST_SLOW_PREINIT to
enable the slowing down of propagating CPU-hotplug changes up the
combining tree along with RCU_TORTURE_TEST_SLOW_PREINIT_DELAY to
specify the delay in jiffies, and RCU_TORTURE_TEST_SLOW_CLEANUP
to enable the slowing down of the end-of-grace-period cleanup scan
along with RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY to specify the delay
in jiffies. Boot-time parameters named rcutree.gp_preinit_delay and
rcutree.gp_cleanup_delay allow these delays to be specified at boot time.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit sets CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y, but leaves the
default time zero. This can be overridden by passing the
"--bootargs rcutree.gp_init_delay=1" argument to kvm.sh.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
A system misconfiguration that prevents qemu from running at all (for
example, a missing dynamically linked library) will keep the console.log
file from the previous run. This can fool the developer into thinking
that this failed run actually completed correctly. This commit therefore
overwrites the console.log file just before launching qemu.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
More recent qemu implementations really want "-enable-kvm", and the
"-soundhw pcspk" makes the script a bit less dependent on odd audio
libraries being installed. This commit therefore adds both to the
default qemu command line.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The mpstat command recently added the %gnice column, which messes up
the cpu2use.sh script's idle-CPU calculations. This commit therefore
uses $NF instead of $12 to select the last (%idle) column.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Normal rcutorture checking overestimates grace periods somewhat due to
the fact that there is a delay from a grace-period request until the
start of the corresponding grace period and another delay from the end
of that grace period to notification of the requestor. This means that
rcutorture's detection of RCU bugs is less sensitive than it might be.
It turns out that rcutorture also checks the underlying grace-period
"completed" counter (displayed in Reader Batch output), which in theory
allows rcutorture to do exact checks. In practice, memory misordering
(by both compiler and CPU) can result in false positives. However,
experience on x86 shows that these false positives are quite rare,
occurring less than one time per 1,000 hours of testing. This commit
therefore does the exact checking, giving a warning if any Reader Batch
blows happen, and flagging an error if they happen more often than
once every three hours in long tests.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The current rcutorture scripting checks for actual stalls (via the "Call
Trace:" check), but fails to spot the case where a stall ends just as it
is being detected. This commit therefore adds a check for this case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that we have removed configs based on kernel version, we can also remove the
kversion parameter in kvm.sh.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Remove rcutorture configuration files which are no longer necessary.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add config and boot parameters to enable the self tests in rcutorture testing.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcutorture scripts create a qemu-cmd script containing the actual
qemu command. However, this command references the build directory,
which will be overwritten by later builds. This commit therefore runs
the kernel out of the results directory so that less hand-editing is
required to re-run a previous test.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
PREEMPT_RCU and TREE_PREEMPT_RCU serve the same function after
TINY_PREEMPT_RCU has been removed. This patch removes TREE_PREEMPT_RCU
and uses PREEMPT_RCU config option in its place.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Rename CONFIG_RCU_BOOST_PRIO to CONFIG_RCU_KTHREAD_PRIO and use this
value for both the per-CPU kthreads (rcuc/N) and the rcu boosting
threads (rcub/n).
Also, create the module_parameter rcutree.kthread_prio to be used on
the kernel command line at boot to set a new value (rcutree.kthread_prio=N).
Signed-off-by: Clark Williams <clark.williams@gmail.com>
[ paulmck: Ported to rcu/dev, applied Paul Bolle and Peter Zijlstra feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add a "rw_lock" torture test to stress kernel rwlocks and their irq
variant. Reader critical regions are 5x longer than writers. As such
a similar ratio of lock acquisitions is seen in the statistics. In the
case of massive contention, both hold the lock for 1/10 of a second.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit changes rcutorture_runnable to torture_runnable, which is
consistent with the names of the other parameters and is a bit shorter
as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although the test cases have been added, they must be specified explicitly
via the kvm.sh --configs argument in order to run them. This commit
therefore adds the RCU-tasks tests to the CFLIST so that they will be
run automatically by default.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds the TASKS01 and TASKS02 Kconfig fragments, along with
the corresponding TASKS01.boot and TASKS02.boot boot-parameter files
specifying that rcutorture test RCU-tasks instead of the default flavor.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When starting a new torture run while an old one is still running, both
qemu processes can be outputting to the same console.out file. This can
cause quite a bit of confusion, so this commit checks for this situation,
which is normally indicated by nul bytes in the console output. Yes,
if your new run uses up an exact number of blocks of the file, this
check will be ineffective, but the odds are not bad.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
This commit specifies offstack cpumasks in TREE07 in order to catch
references to unallocated cpumask_var_t variables.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Setting CONFIG_MAXSMP=y causes cpumasks to be moved offstack, which
introduces the possibility of NULL cpumask_var_t pointers. This commit
therefore enables CONFIG_MAXSMP=y in TREE01 to increase test coverage.
However, because CONFIG_MAXSMP=y implies 8192 CPUs, we need to use
the maxcpus= boot parameter to limit the number of CPUs to something
reasonable, which in turn requires updating the scripts to handle this.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
The current set of tests covers only cases where either all possible CPUs
are nohz_full= CPUs or none of them are. Because there have been some
recent bug escapes in cases where only some of the CPUs are nohz_full=
CPUs, this commit add a configuration where only half of the CPUs are
nohz_full= CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
This commit tries to get people into the correct directory before
creating the initrd directory.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
This commit sets the executable bit on test scripts config2frag.sh
and kvm.sh. Since #!/bin/bash is set in all the scripts, this commit
also drops it from all usage lines because the scripts can now all be
invoked directly.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Some of the scripts encode a default /bin/sh shell. On systems which use
dash as default shell, these scripts fail as they are bash scripts. I
encountered this while testing the sprintf() changes on a Debian system
where dash is the default shell.
This commit changes all such uses to use bash explicitly.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney