Because %p prints "(null)" and %pK prints "0000000000000000" or (on
32-bit systems) "00000000", this commit adjusts torture-test scripting
accordingly.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull core locking updates from Ingo Molnar:
"The main changes in this cycle are:
- Another attempt at enabling cross-release lockdep dependency
tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time
with better performance and fewer false positives. (Byungchul Park)
- Introduce lockdep_assert_irqs_enabled()/disabled() and convert
open-coded equivalents to lockdep variants. (Frederic Weisbecker)
- Add down_read_killable() and use it in the VFS's iterate_dir()
method. (Kirill Tkhai)
- Convert remaining uses of ACCESS_ONCE() to
READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle
driven. (Mark Rutland, Paul E. McKenney)
- Get rid of lockless_dereference(), by strengthening Alpha atomics,
strengthening READ_ONCE() with smp_read_barrier_depends() and thus
being able to convert users of lockless_dereference() to
READ_ONCE(). (Will Deacon)
- Various micro-optimizations:
- better PV qspinlocks (Waiman Long),
- better x86 barriers (Michael S. Tsirkin)
- better x86 refcounts (Kees Cook)
- ... plus other fixes and enhancements. (Borislav Petkov, Juergen
Gross, Miguel Bernal Marin)"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE
rcu: Use lockdep to assert IRQs are disabled/enabled
netpoll: Use lockdep to assert IRQs are disabled/enabled
timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled
sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled
irq_work: Use lockdep to assert IRQs are disabled/enabled
irq/timings: Use lockdep to assert IRQs are disabled/enabled
perf/core: Use lockdep to assert IRQs are disabled/enabled
x86: Use lockdep to assert IRQs are disabled/enabled
smp/core: Use lockdep to assert IRQs are disabled/enabled
timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled
timers/nohz: Use lockdep to assert IRQs are disabled/enabled
workqueue: Use lockdep to assert IRQs are disabled/enabled
irq/softirqs: Use lockdep to assert IRQs are disabled/enabled
locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled()
locking/pvqspinlock: Implement hybrid PV queued/unfair locks
locking/rwlocks: Fix comments
x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized
block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()
workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes
...
Pull RCU updates from Ingo Molnar:
"The main changes in this cycle are:
- Documentation updates
- RCU CPU stall-warning updates
- Torture-test updates
- Miscellaneous fixes
Size wise the biggest updates are to documentation. Excluding
documentation most of the code increase comes from a single commit
which expands debugging"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
srcu: Add parameters to SRCU docbook comments
doc: Rewrite confusing statement about memory barriers
memory-barriers.txt: Fix typo in pairing example
rcu/segcblist: Include rcupdate.h
rcu: Add extended-quiescent-state testing advice
rcu: Suppress lockdep false-positive ->boost_mtx complaints
rcu: Do not include rtmutex_common.h unconditionally
torture: Provide TMPDIR environment variable to specify tmpdir
rcutorture: Dump writer stack if stalled
rcutorture: Add interrupt-disable capability to stall-warning tests
rcu: Suppress RCU CPU stall warnings while dumping trace
rcu: Turn off tracing before dumping trace
rcu: Make RCU CPU stall warnings check for irq-disabled CPUs
sched,rcu: Make cond_resched() provide RCU quiescent state
sched: Make resched_cpu() unconditional
irq_work: Map irq_work_on_queue() to irq_work_on() in !SMP
rcu: Create call_rcu_tasks() kthread at boot time
rcu: Fix up pending cbs check in rcu_prepare_for_idle
memory-barriers: Rework multicopy-atomicity section
memory-barriers: Replace uses of "transitive"
...
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't currently harmful.
However, for some features it is necessary to instrument reads and
writes separately, which is not possible with ACCESS_ONCE(). This
distinction is critical to correct operation.
The bulk of the kernel code can be transformed via Coccinelle to use
{READ,WRITE}_ONCE(), though this only modifies users of ACCESS_ONCE(),
and not the implementation itself. As such, it has the potential to
break homebrew ACCESS_ONCE() macros seen in some user code in the kernel
tree (e.g. the virtio code, as fixed in commit ea9156fb3b).
To avoid fragility if/when that transformation occurs, this patch
reworks the definitions of {READ,WRITE}_ONCE() in the rcutorture formal
tests, and removes the unused ACCESS_ONCE() helper. There should be no
functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-13-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Both rcutorture and locktorture currently place temporary files in /tmp,
in keeping with decades-long tradition. However, sometimes it is useful
to specify an alternative temporary directory, for example, for space
or performance reasons. This commit therefore causes the torture-test
scripting to use the path specified in the TMPDIR environment variable,
or to fall back to traditional /tmp if this variable is not set.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The actual use of TASKS_RCU is only when PREEMPT, otherwise RCU-sched
is used instead. This commit therefore makes synchronize_rcu_tasks()
and call_rcu_tasks() available always, but mapped to synchronize_sched()
and call_rcu_sched(), respectively, when !PREEMPT. This approach also
allows some #ifdefs to be removed from rcutorture.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
The maxcpus= kernel boot parameter limits the number of CPUs brought
online at boot time, but it does nothing to prevent additional CPUs
from being brought up later. Placing a hard cap on the total number
of CPUs is instead the job of the nr_cpus= boot parameter. This commit
therefore switches the configfrag_boot_cpus() shell function from maxcpus=
to nr_cpus=. This commit also adds a nr_cpus=43 kernel parameter to RCU's
TREE01 test scenario, but retains the maxcpus=8 kernel parameter in order
to test the ability of RCU expedited grace periods to handle new CPUs
coming online for the first time during grace-period initialization.
Finally, this commit makes the torture scheduling allow maxcpus= to
override other means of specifying the number of CPUs to allow for.
This last works because the torture kernel modules size their workloads
based on the number of CPUs present at the start of the test, not the
ultimate number of CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Strings used in event tracing need to be specially handled, for example,
being copied to the trace buffer instead of being pointed to by the trace
buffer. Although the TPS() macro can be used to "launder" pointed-to
strings, this might not be all that effective within a loadable module.
This commit therefore copies rcutorture's strings to the trace buffer.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Currently, rcutorture groups runs in batches, building each scenario in
a given batch, then invoking qemu to run all the kernels in the batch.
Of course, if a given scenario's kernel fails to build, there is no qemu
run for that scenario. And if all of the kernels in a given batch fail
to build, there are no runs, and rcutorture immediately starts on the
next batch.
But not if --jitter has been specified, which it is by default. In this
case, the jitter scripts are started unconditionally, and rcutorture
waits for them to complete, even though there are no kernels to run.
This commit therefore checks for this situation, and refuses to start
jitter unless at least one of the kernels in the batch built successfully.
This saves substantial time when all scenarios' kernels fail to build,
particularly if a long --duration was specified.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, testing a variant of an existing scenario requires editing
that scenario's file or creating a new scenario file. This is messy
and error prone with respect to changes to scenarios.
This commit therefore adds a --kconfig argument to kvm.sh, so that
'--kconfig "CONFIG_RCU_TRACE=y CONFIG_RCU_EQS_DEBUG=n" will override those
two Kconfig options. In addition, there is now clear precedence:
the config fragment overrides CFcommon, and the --kconfig argument
overrides both.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit selects CONFIG_PROVE_LOCKING for the SRCU-u scenario
to get better test coverage.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Classic SRCU is no more, so this commit removes the corresponding
rcutorture boot-parameters file.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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: Paul 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: Paul 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: Paul 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: Paul 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: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul 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: Paul 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 0edd1b1784 ("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: Paul 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: Linus 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: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul 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: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul 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: Paul 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: Kushwaha, Priyalee <priyalee.kushwaha@intel.com>
Acked-by: Lance Roy <ldr709@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull locking updates from Ingo Molnar:
"The main changes in this cycle were:
- Implement wraparound-safe refcount_t and kref_t types based on
generic atomic primitives (Peter Zijlstra)
- Improve and fix the ww_mutex code (Nicolai Hähnle)
- Add self-tests to the ww_mutex code (Chris Wilson)
- Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr
Bueso)
- Micro-optimize the current-task logic all around the core kernel
(Davidlohr Bueso)
- Tidy up after recent optimizations: remove stale code and APIs,
clean up the code (Waiman Long)
- ... plus misc fixes, updates and cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
fork: Fix task_struct alignment
locking/spinlock/debug: Remove spinlock lockup detection code
lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS
lkdtm: Convert to refcount_t testing
kref: Implement 'struct kref' using refcount_t
refcount_t: Introduce a special purpose refcount type
sched/wake_q: Clarify queue reinit comment
sched/wait, rcuwait: Fix typo in comment
locking/mutex: Fix lockdep_assert_held() fail
locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock()
locking/rwsem: Reinit wake_q after use
locking/rwsem: Remove unnecessary atomic_long_t casts
jump_labels: Move header guard #endif down where it belongs
locking/atomic, kref: Implement kref_put_lock()
locking/ww_mutex: Turn off __must_check for now
locking/atomic, kref: Avoid more abuse
locking/atomic, kref: Use kref_get_unless_zero() more
locking/atomic, kref: Kill kref_sub()
locking/atomic, kref: Add kref_read()
locking/atomic, kref: Add KREF_INIT()
...
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: Lance Roy <ldr709@gmail.com>
Signed-off-by: Paul 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: "Ahmed, Iftekhar" <ahmedi@oregonstate.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit adds CONFIG_PROVE_RCU_REPEATEDLY=y, which has been untested
for quite some time.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit verifies coverage of testing with CONFIG_RCU_STALL_COMMON=n.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh 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: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter 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.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
