This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
scf_handler() is used as a SMP function call. This function is always
invoked in IRQ-context even with forced-threading enabled. This function
frees memory which not allowed on PREEMPT_RT because the locking
underneath is using sleeping locks.
Add a per-CPU scf_free_pool where each SMP functions adds its memory to
be freed. This memory is then freed by scftorture_invoker() on each
iteration. On the majority of invocations the number of items is less
than five. If the thread sleeps/ gets delayed the number exceed 350 but
did not reach 400 in testing. These were the spikes during testing.
The bulk free of 64 pointers at once should improve the give-back if the
list grows. The list size is ~1.3 items per invocations.
Having one global scf_free_pool with one cleaning thread let the list
grow to over 10.000 items with 32 CPUs (again, spikes not the average)
especially if the CPU went to sleep. The per-CPU part looks like a good
compromise.
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Closes: https://lore.kernel.org/lkml/41619255-cdc2-4573-a360-7794fc3614f7@paulmck-laptop/
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Memory allocations can not happen within regions with explicit disabled
preemption PREEMPT_RT. The problem is that the locking structures
underneath are sleeping locks.
Move the memory allocation outside of the preempt-disabled section. Keep
the GFP_ATOMIC for the allocation to behave like a "ememergncy
allocation".
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The smp_call_function() needs to be invoked with the wait flag set to
wait until scf_cleanup_handler() is done. This ensures that all SMP
function calls, that have been queued earlier, complete at this point.
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Fix the 'make C=1' warning:
kernel/scftorture.c:71:6: warning: symbol 'torture_type' was not declared. Should it be static?
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Fix the 'make W=1' warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/scftorture.o
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The scftorture test can quickly execute a large number of calls to no-wait
smp_call_function(), each of which holds a block of memory until the
corresponding handler is invoked. Especially when the longwait module
parameter is specified, this can chew up an arbitrarily large amount
of memory. This commit therefore blocks after each memory-allocation
failure, with the duration a function of longwait.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Kernels built with CONFIG_KASAN=y quarantine newly freed memory in order
to better detect use-after-free errors. However, this can exhaust memory
more quickly in allocator-heavy tests, which can result in spurious
scftorture failure. This commit therefore forgives memory-allocation
failure in kernels built with CONFIG_KASAN=y, but continues counting
the errors for use in detailed test-result analyses.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The scftorture test module's scf_handler() function is supposed to provide
three different distributions of short delays (including "no delay") and
one distribution of long delays, if specified by the scftorture.longwait
module parameter. However, the second of the two non-zero-wait short delays
is disabled due to the first such delay's "goto out" not being enclosed in
the "then" clause with the "udelay()".
This commit therefore adjusts the code to provide the intended set of
delays.
Fixes: e9d338a0b1 ("scftorture: Add smp_call_function() torture test")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
There are no longer any users of SCFTORTOUT(), so this commit removes it.
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Li Zhijian <zhijianx.li@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
When running scftorture as a module, any scf_torture_init() issues will be
reflected in the error code from modprobe or insmod, as the case may be.
However, these error codes are not available when running scftorture
built-in, for example, when using the kvm.sh script. This commit
therefore adds WARN_ON_ONCE() to allow distinguishing scf_torture_init()
errors when running scftorture built-in.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, only those IPIs that invoke scftorture's scf_handler()
IPI handler function are counted. This means that runs exercising
only scftorture.weight_resched will look like they have made no forward
progress, resulting in "GP HANG" complaints from the rcutorture scripting.
This commit therefore increments the scf_invoked_count per-CPU counter
immediately after calling resched_cpu().
Fixes: 1ac78b49d6 ("scftorture: Add an alternative IPI vector")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The "all zero weights makes no sense" error is emitted even when
scftorture.weight_resched is non-zero because it was left out of
the enclosing "if" condition. This commit adds it in.
Fixes: 1ac78b49d6 ("scftorture: Add an alternative IPI vector")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If (say) a 10-hour scftorture run is started, but the module parameters
are so nonsensical that the run doesn't even start, then scftorture will
wait the full ten hours when run built into a guest OS. This commit
therefore shuts down the system in this case so that the error is reported
immediately instead of ten hours hence.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit reworks the weighting calculations to allow zero to
be specified to disable a given weight. For example, specifying the
scftorture.weight_resched=0 kernel boot parameter without specifying a
non-zero value for any of the other scftorture.weight_* parameters would
provide the default weights for the others, but would refrain from doing
any resched-based IPIs.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
When scftorture finds an error in the module parameters controlling
the relative frequencies of smp_call_function*() variants, it takes an
early exit. So early that it has not allocated memory to track the
kthreads running the test, which results in a segfault. This commit
therefore checks for the existence of the memory before attempting
to stop the kthreads that would otherwise have been recorded in that
non-existent memory.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds the single_weight_rpc module parameter, which causes the
IPI handler to awaken the IPI sender. In many scheduler configurations,
this will result in an IPI back to the sender that is likely to be
received at a time when the sender CPU is idle. The intent is to stress
IPI reception during CPU busy-to-idle transitions.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If the call to set_cpus_allowed_ptr() in scftorture_invoker()
fails, a later WARN_ONCE() complains. But with the advent of
570a752b7a ("lib/smp_processor_id: Use is_percpu_thread() instead of
nr_cpus_allowed"), this complaint can be drowned out by complaints from
smp_processor_id(). The rationale for this change is that scftorture's
kthreads are not marked with PF_NO_SETAFFINITY, which means that a system
administrator could change affinity at any time.
However, scftorture is a torture test, and the system administrator might
well have a valid test-the-test reason for changing affinity. This commit
therefore changes to raw_smp_processor_id() in order to avoid the noise,
and also adds a WARN_ON_ONCE() to the call to set_cpus_allowed_ptr() in
order to directly detect immediate failure. There is no WARN_ON_ONCE()
within the test loop, allowing human-reflex-based affinity resetting,
if desired.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds the desired CPU, the actual CPU, and nr_cpu_ids to
the wrong-CPU warning in scftorture_invoker(), the better to help with
debugging.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
In virtual environments on systems with hardware assist, inter-processor
interrupts must do very different things based on whether the target
vCPU is running or not. This commit therefore enables torture-test
stuttering to better test these running/not-running transitions.
Suggested-by: Chris Mason <clm@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
