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Commit e7d38f16 authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'rcu.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 

Pull RCU updates from Paul McKenney:

 - Documentation updates, perhaps most notably Neil Brown's writeup of
   the reference-counting analogy to RCU.

 - Expedited grace-period cleanups.

 - Remove CONFIG_RCU_FAST_NO_HZ due to lack of valid users. I have asked
   around, posted a blog entry, and sent this series to LKML without
   result.

 - Miscellaneous fixes.

 - RCU callback offloading updates, perhaps most notably Frederic
   Weisbecker's updates allowing CPUs booted in the de-offloaded state
   to be offloaded at runtime.

 - nolibc fixes from Willy Tarreau and Anmar Faizi, but also including
   Mark Brown's addition of gettid().

 - RCU Tasks Trace fixes, including changes that increase the
   scalability of call_rcu_tasks_trace() for the BPF folks (Martin Lau
   and KP Singh).

 - Various fixes including those from Wander Lairson Costa and Li
   Zhijian.

 - Fixes plus addition of tests for the increased call_rcu_tasks_trace()
   scalability.

* tag 'rcu.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (87 commits)
  rcu/nocb: Merge rcu_spawn_cpu_nocb_kthread() and rcu_spawn_one_nocb_kthread()
  rcu/nocb: Allow empty "rcu_nocbs" kernel parameter
  rcu/nocb: Create kthreads on all CPUs if "rcu_nocbs=" or "nohz_full=" are passed
  rcu/nocb: Optimize kthreads and rdp initialization
  rcu/nocb: Prepare nocb_cb_wait() to start with a non-offloaded rdp
  rcu/nocb: Remove rcu_node structure from nocb list when de-offloaded
  rcu-tasks: Use fewer callbacks queues if callback flood ends
  rcu-tasks: Use separate ->percpu_dequeue_lim for callback dequeueing
  rcu-tasks: Use more callback queues if contention encountered
  rcu-tasks: Avoid raw-spinlocked wakeups from call_rcu_tasks_generic()
  rcu-tasks: Count trylocks to estimate call_rcu_tasks() contention
  rcu-tasks: Add rcupdate.rcu_task_enqueue_lim to set initial queueing
  rcu-tasks: Make rcu_barrier_tasks*() handle multiple callback queues
  rcu-tasks: Use workqueues for multiple rcu_tasks_invoke_cbs() invocations
  rcu-tasks: Abstract invocations of callbacks
  rcu-tasks: Abstract checking of callback lists
  rcu-tasks: Add a ->percpu_enqueue_lim to the rcu_tasks structure
  rcu-tasks: Inspect stalled task's trc state in locked state
  rcu-tasks: Use spin_lock_rcu_node() and friends
  rcutorture: Combine n_max_cbs from all kthreads in a callback flood
  ...
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......@@ -254,17 +254,6 @@ period (in this case 2603), the grace-period sequence number (7075), and
an estimate of the total number of RCU callbacks queued across all CPUs
(625 in this case).
In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed
for each CPU::
0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 dyntick_enabled: 1
The "last_accelerate:" prints the low-order 16 bits (in hex) of the
jiffies counter when this CPU last invoked rcu_try_advance_all_cbs()
from rcu_needs_cpu() or last invoked rcu_accelerate_cbs() from
rcu_prepare_for_idle(). "dyntick_enabled: 1" indicates that dyntick-idle
processing is enabled.
If the grace period ends just as the stall warning starts printing,
there will be a spurious stall-warning message, which will include
the following::
......
Documentation/RCU/whatisRCU.rst
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......@@ -39,9 +39,11 @@ different paths, as follows:
:ref:`6. ANALOGY WITH READER-WRITER LOCKING <6_whatisRCU>`
:ref:`7. FULL LIST OF RCU APIs <7_whatisRCU>`
:ref:`7. ANALOGY WITH REFERENCE COUNTING <7_whatisRCU>`
:ref:`8. ANSWERS TO QUICK QUIZZES <8_whatisRCU>`
:ref:`8. FULL LIST OF RCU APIs <8_whatisRCU>`
:ref:`9. ANSWERS TO QUICK QUIZZES <9_whatisRCU>`
People who prefer starting with a conceptual overview should focus on
Section 1, though most readers will profit by reading this section at
......@@ -677,7 +679,7 @@ Quick Quiz #1:
occur when using this algorithm in a real-world Linux
kernel? How could this deadlock be avoided?
:ref:`Answers to Quick Quiz <8_whatisRCU>`
:ref:`Answers to Quick Quiz <9_whatisRCU>`
5B. "TOY" EXAMPLE #2: CLASSIC RCU
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
......@@ -732,7 +734,7 @@ Quick Quiz #2:
Give an example where Classic RCU's read-side
overhead is **negative**.
:ref:`Answers to Quick Quiz <8_whatisRCU>`
:ref:`Answers to Quick Quiz <9_whatisRCU>`
.. _quiz_3:
......@@ -741,7 +743,7 @@ Quick Quiz #3:
critical section, what the heck do you do in
CONFIG_PREEMPT_RT, where normal spinlocks can block???
:ref:`Answers to Quick Quiz <8_whatisRCU>`
:ref:`Answers to Quick Quiz <9_whatisRCU>`
.. _6_whatisRCU:
......@@ -872,7 +874,79 @@ be used in place of synchronize_rcu().
.. _7_whatisRCU:
7. FULL LIST OF RCU APIs
7. ANALOGY WITH REFERENCE COUNTING
-----------------------------------
The reader-writer analogy (illustrated by the previous section) is not
always the best way to think about using RCU. Another helpful analogy
considers RCU an effective reference count on everything which is
protected by RCU.
A reference count typically does not prevent the referenced object's
values from changing, but does prevent changes to type -- particularly the
gross change of type that happens when that object's memory is freed and
re-allocated for some other purpose. Once a type-safe reference to the
object is obtained, some other mechanism is needed to ensure consistent
access to the data in the object. This could involve taking a spinlock,
but with RCU the typical approach is to perform reads with SMP-aware
operations such as smp_load_acquire(), to perform updates with atomic
read-modify-write operations, and to provide the necessary ordering.
RCU provides a number of support functions that embed the required
operations and ordering, such as the list_for_each_entry_rcu() macro
used in the previous section.
A more focused view of the reference counting behavior is that,
between rcu_read_lock() and rcu_read_unlock(), any reference taken with
rcu_dereference() on a pointer marked as ``__rcu`` can be treated as
though a reference-count on that object has been temporarily increased.
This prevents the object from changing type. Exactly what this means
will depend on normal expectations of objects of that type, but it
typically includes that spinlocks can still be safely locked, normal
reference counters can be safely manipulated, and ``__rcu`` pointers
can be safely dereferenced.
Some operations that one might expect to see on an object for
which an RCU reference is held include:
- Copying out data that is guaranteed to be stable by the object's type.
- Using kref_get_unless_zero() or similar to get a longer-term
reference. This may fail of course.
- Acquiring a spinlock in the object, and checking if the object still
is the expected object and if so, manipulating it freely.
The understanding that RCU provides a reference that only prevents a
change of type is particularly visible with objects allocated from a
slab cache marked ``SLAB_TYPESAFE_BY_RCU``. RCU operations may yield a
reference to an object from such a cache that has been concurrently
freed and the memory reallocated to a completely different object,
though of the same type. In this case RCU doesn't even protect the
identity of the object from changing, only its type. So the object
found may not be the one expected, but it will be one where it is safe
to take a reference or spinlock and then confirm that the identity
matches the expectations.
With traditional reference counting -- such as that implemented by the
kref library in Linux -- there is typically code that runs when the last
reference to an object is dropped. With kref, this is the function
passed to kref_put(). When RCU is being used, such finalization code
must not be run until all ``__rcu`` pointers referencing the object have
been updated, and then a grace period has passed. Every remaining
globally visible pointer to the object must be considered to be a
potential counted reference, and the finalization code is typically run
using call_rcu() only after all those pointers have been changed.
To see how to choose between these two analogies -- of RCU as a
reader-writer lock and RCU as a reference counting system -- it is useful
to reflect on the scale of the thing being protected. The reader-writer
lock analogy looks at larger multi-part objects such as a linked list
and shows how RCU can facilitate concurrency while elements are added
to, and removed from, the list. The reference-count analogy looks at
the individual objects and looks at how they can be accessed safely
within whatever whole they are a part of.
.. _8_whatisRCU:
8. FULL LIST OF RCU APIs
-------------------------
The RCU APIs are documented in docbook-format header comments in the
......@@ -1035,9 +1109,9 @@ g. Otherwise, use RCU.
Of course, this all assumes that you have determined that RCU is in fact
the right tool for your job.
.. _8_whatisRCU:
.. _9_whatisRCU:
8. ANSWERS TO QUICK QUIZZES
9. ANSWERS TO QUICK QUIZZES
----------------------------
Quick Quiz #1:
......
Documentation/admin-guide/kernel-parameters.txt
View file @ e7d38f16
......@@ -4365,19 +4365,30 @@
Disable the Correctable Errors Collector,
see CONFIG_RAS_CEC help text.
rcu_nocbs= [KNL]
The argument is a cpu list, as described above.
In kernels built with CONFIG_RCU_NOCB_CPU=y, set
the specified list of CPUs to be no-callback CPUs.
Invocation of these CPUs' RCU callbacks will be
offloaded to "rcuox/N" kthreads created for that
purpose, where "x" is "p" for RCU-preempt, and
"s" for RCU-sched, and "N" is the CPU number.
This reduces OS jitter on the offloaded CPUs,
which can be useful for HPC and real-time
workloads. It can also improve energy efficiency
for asymmetric multiprocessors.
rcu_nocbs[=cpu-list]
[KNL] The optional argument is a cpu list,
as described above.
In kernels built with CONFIG_RCU_NOCB_CPU=y,
enable the no-callback CPU mode, which prevents
such CPUs' callbacks from being invoked in
softirq context. Invocation of such CPUs' RCU
callbacks will instead be offloaded to "rcuox/N"
kthreads created for that purpose, where "x" is
"p" for RCU-preempt, "s" for RCU-sched, and "g"
for the kthreads that mediate grace periods; and
"N" is the CPU number. This reduces OS jitter on
the offloaded CPUs, which can be useful for HPC
and real-time workloads. It can also improve
energy efficiency for asymmetric multiprocessors.
If a cpulist is passed as an argument, the specified
list of CPUs is set to no-callback mode from boot.
Otherwise, if the '=' sign and the cpulist
arguments are omitted, no CPU will be set to
no-callback mode from boot but the mode may be
toggled at runtime via cpusets.
rcu_nocb_poll [KNL]
Rather than requiring that offloaded CPUs
......@@ -4511,10 +4522,6 @@
on rcutree.qhimark at boot time and to zero to
disable more aggressive help enlistment.
rcutree.rcu_idle_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
RCU callbacks (RCU_FAST_NO_HZ=y).
rcutree.rcu_kick_kthreads= [KNL]
Cause the grace-period kthread to get an extra
wake_up() if it sleeps three times longer than
......@@ -4625,8 +4632,12 @@
in seconds.
rcutorture.fwd_progress= [KNL]
Enable RCU grace-period forward-progress testing
Specifies the number of kthreads to be used
for RCU grace-period forward-progress testing
for the types of RCU supporting this notion.
Defaults to 1 kthread, values less than zero or
greater than the number of CPUs cause the number
of CPUs to be used.
rcutorture.fwd_progress_div= [KNL]
Specify the fraction of a CPU-stall-warning
......@@ -4827,6 +4838,29 @@
period to instead use normal non-expedited
grace-period processing.
rcupdate.rcu_task_collapse_lim= [KNL]
Set the maximum number of callbacks present
at the beginning of a grace period that allows
the RCU Tasks flavors to collapse back to using
a single callback queue. This switching only
occurs when rcupdate.rcu_task_enqueue_lim is
set to the default value of -1.
rcupdate.rcu_task_contend_lim= [KNL]
Set the minimum number of callback-queuing-time
lock-contention events per jiffy required to
cause the RCU Tasks flavors to switch to per-CPU
callback queuing. This switching only occurs
when rcupdate.rcu_task_enqueue_lim is set to
the default value of -1.
rcupdate.rcu_task_enqueue_lim= [KNL]
Set the number of callback queues to use for the
RCU Tasks family of RCU flavors. The default
of -1 allows this to be automatically (and
dynamically) adjusted. This parameter is intended
for use in testing.
rcupdate.rcu_task_ipi_delay= [KNL]
Set time in jiffies during which RCU tasks will
avoid sending IPIs, starting with the beginning
......
Documentation/admin-guide/kernel-per-CPU-kthreads.rst
View file @ e7d38f16
......@@ -208,7 +208,7 @@ Do at least one of the following:
2. Enable RCU to do its processing remotely via dyntick-idle by
doing all of the following:
a. Build with CONFIG_NO_HZ=y and CONFIG_RCU_FAST_NO_HZ=y.
a. Build with CONFIG_NO_HZ=y.
b. Ensure that the CPU goes idle frequently, allowing other
CPUs to detect that it has passed through an RCU quiescent
state. If the kernel is built with CONFIG_NO_HZ_FULL=y,
......
Documentation/timers/no_hz.rst
View file @ e7d38f16
......@@ -184,16 +184,12 @@ There are situations in which idle CPUs cannot be permitted to
enter either dyntick-idle mode or adaptive-tick mode, the most
common being when that CPU has RCU callbacks pending.
The CONFIG_RCU_FAST_NO_HZ=y Kconfig option may be used to cause such CPUs
to enter dyntick-idle mode or adaptive-tick mode anyway. In this case,
a timer will awaken these CPUs every four jiffies in order to ensure
that the RCU callbacks are processed in a timely fashion.
Another approach is to offload RCU callback processing to "rcuo" kthreads
Avoid this by offloading RCU callback processing to "rcuo" kthreads
using the CONFIG_RCU_NOCB_CPU=y Kconfig option. The specific CPUs to
offload may be selected using The "rcu_nocbs=" kernel boot parameter,
which takes a comma-separated list of CPUs and CPU ranges, for example,
"1,3-5" selects CPUs 1, 3, 4, and 5.
"1,3-5" selects CPUs 1, 3, 4, and 5. Note that CPUs specified by
the "nohz_full" kernel boot parameter are also offloaded.
The offloaded CPUs will never queue RCU callbacks, and therefore RCU
never prevents offloaded CPUs from entering either dyntick-idle mode
......
include/linux/rcu_segcblist.h
View file @ e7d38f16
......@@ -69,7 +69,7 @@ struct rcu_cblist {
*
*
* ----------------------------------------------------------------------------
* | SEGCBLIST_SOFTIRQ_ONLY |
* | SEGCBLIST_RCU_CORE |
* | |
* | Callbacks processed by rcu_core() from softirqs or local |
* | rcuc kthread, without holding nocb_lock. |
......@@ -77,7 +77,7 @@ struct rcu_cblist {
* |
* v
* ----------------------------------------------------------------------------
* | SEGCBLIST_OFFLOADED |
* | SEGCBLIST_RCU_CORE | SEGCBLIST_LOCKING | SEGCBLIST_OFFLOADED |
* | |
* | Callbacks processed by rcu_core() from softirqs or local |
* | rcuc kthread, while holding nocb_lock. Waking up CB and GP kthreads, |
......@@ -89,7 +89,9 @@ struct rcu_cblist {
* | |
* v v
* --------------------------------------- ----------------------------------|
* | SEGCBLIST_OFFLOADED | | | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_RCU_CORE | | | SEGCBLIST_RCU_CORE | |
* | SEGCBLIST_LOCKING | | | SEGCBLIST_LOCKING | |
* | SEGCBLIST_OFFLOADED | | | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_KTHREAD_CB | | SEGCBLIST_KTHREAD_GP |
* | | | |
* | | | |
......@@ -104,9 +106,10 @@ struct rcu_cblist {
* |
* v
* |--------------------------------------------------------------------------|
* | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_KTHREAD_CB | |
* | SEGCBLIST_KTHREAD_GP |
* | SEGCBLIST_LOCKING | |
* | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_KTHREAD_GP | |
* | SEGCBLIST_KTHREAD_CB |
* | |
* | Kthreads handle callbacks holding nocb_lock, local rcu_core() stops |
* | handling callbacks. Enable bypass queueing. |
......@@ -120,7 +123,8 @@ struct rcu_cblist {
*
*
* |--------------------------------------------------------------------------|
* | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_LOCKING | |
* | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_KTHREAD_CB | |
* | SEGCBLIST_KTHREAD_GP |
* | |
......@@ -130,6 +134,22 @@ struct rcu_cblist {
* |
* v
* |--------------------------------------------------------------------------|
* | SEGCBLIST_RCU_CORE | |
* | SEGCBLIST_LOCKING | |
* | SEGCBLIST_OFFLOADED | |
* | SEGCBLIST_KTHREAD_CB | |
* | SEGCBLIST_KTHREAD_GP |
* | |
* | CB/GP kthreads handle callbacks holding nocb_lock, local rcu_core() |
* | handles callbacks concurrently. Bypass enqueue is enabled. |
* | Invoke RCU core so we make sure not to preempt it in the middle with |
* | leaving some urgent work unattended within a jiffy. |
* ----------------------------------------------------------------------------
* |
* v
* |--------------------------------------------------------------------------|
* | SEGCBLIST_RCU_CORE | |
* | SEGCBLIST_LOCKING | |
* | SEGCBLIST_KTHREAD_CB | |
* | SEGCBLIST_KTHREAD_GP |
* | |
......@@ -143,7 +163,9 @@ struct rcu_cblist {
* | |
* v v
* ---------------------------------------------------------------------------|
* | |
* | | |
* | SEGCBLIST_RCU_CORE | | SEGCBLIST_RCU_CORE | |
* | SEGCBLIST_LOCKING | | SEGCBLIST_LOCKING | |
* | SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP |
* | | |
* | GP kthread woke up and | CB kthread woke up and |
......@@ -159,7 +181,7 @@ struct rcu_cblist {
* |
* v
* ----------------------------------------------------------------------------
* | 0 |
* | SEGCBLIST_RCU_CORE | SEGCBLIST_LOCKING |
* | |
* | Callbacks processed by rcu_core() from softirqs or local |
* | rcuc kthread, while holding nocb_lock. Forbid nocb_timer to be armed. |
......@@ -168,17 +190,18 @@ struct rcu_cblist {
* |
* v
* ----------------------------------------------------------------------------
* | SEGCBLIST_SOFTIRQ_ONLY |
* | SEGCBLIST_RCU_CORE |
* | |
* | Callbacks processed by rcu_core() from softirqs or local |
* | rcuc kthread, without holding nocb_lock. |
* ----------------------------------------------------------------------------
*/
#define SEGCBLIST_ENABLED BIT(0)
#define SEGCBLIST_SOFTIRQ_ONLY BIT(1)
#define SEGCBLIST_KTHREAD_CB BIT(2)
#define SEGCBLIST_KTHREAD_GP BIT(3)
#define SEGCBLIST_OFFLOADED BIT(4)
#define SEGCBLIST_RCU_CORE BIT(1)
#define SEGCBLIST_LOCKING BIT(2)
#define SEGCBLIST_KTHREAD_CB BIT(3)
#define SEGCBLIST_KTHREAD_GP BIT(4)
#define SEGCBLIST_OFFLOADED BIT(5)
struct rcu_segcblist {
struct rcu_head *head;
......
include/linux/rcupdate.h
View file @ e7d38f16
......@@ -364,6 +364,12 @@ static inline void rcu_preempt_sleep_check(void) { }
#define rcu_check_sparse(p, space)
#endif /* #else #ifdef __CHECKER__ */
#define __unrcu_pointer(p, local) \
({ \
typeof(*p) *local = (typeof(*p) *__force)(p); \
rcu_check_sparse(p, __rcu); \
((typeof(*p) __force __kernel *)(local)); \
})
/**
* unrcu_pointer - mark a pointer as not being RCU protected
* @p: pointer needing to lose its __rcu property
......@@ -371,39 +377,35 @@ static inline void rcu_preempt_sleep_check(void) { }
* Converts @p from an __rcu pointer to a __kernel pointer.
* This allows an __rcu pointer to be used with xchg() and friends.
*/
#define unrcu_pointer(p) \
({ \
typeof(*p) *_________p1 = (typeof(*p) *__force)(p); \
rcu_check_sparse(p, __rcu); \
((typeof(*p) __force __kernel *)(_________p1)); \
})
#define unrcu_pointer(p) __unrcu_pointer(p, __UNIQUE_ID(rcu))
#define __rcu_access_pointer(p, space) \
#define __rcu_access_pointer(p, local, space) \
({ \
typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \
typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
rcu_check_sparse(p, space); \
((typeof(*p) __force __kernel *)(_________p1)); \
((typeof(*p) __force __kernel *)(local)); \
})
#define __rcu_dereference_check(p, c, space) \
#define __rcu_dereference_check(p, local, c, space) \
({ \
/* Dependency order vs. p above. */ \
typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \
typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \
rcu_check_sparse(p, space); \
((typeof(*p) __force __kernel *)(________p1)); \
((typeof(*p) __force __kernel *)(local)); \
})
#define __rcu_dereference_protected(p, c, space) \
#define __rcu_dereference_protected(p, local, c, space) \
({ \
RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \
rcu_check_sparse(p, space); \
((typeof(*p) __force __kernel *)(p)); \
})
#define rcu_dereference_raw(p) \
#define __rcu_dereference_raw(p, local) \
({ \
/* Dependency order vs. p above. */ \
typeof(p) ________p1 = READ_ONCE(p); \
((typeof(*p) __force __kernel *)(________p1)); \
typeof(p) local = READ_ONCE(p); \
((typeof(*p) __force __kernel *)(local)); \
})
#define rcu_dereference_raw(p) __rcu_dereference_raw(p, __UNIQUE_ID(rcu))
/**
* RCU_INITIALIZER() - statically initialize an RCU-protected global variable
......@@ -490,7 +492,7 @@ do { \
* when tearing down multi-linked structures after a grace period
* has elapsed.
*/
#define rcu_access_pointer(p) __rcu_access_pointer((p), __rcu)
#define rcu_access_pointer(p) __rcu_access_pointer((p), __UNIQUE_ID(rcu), __rcu)
/**
* rcu_dereference_check() - rcu_dereference with debug checking
......@@ -526,7 +528,8 @@ do { \
* annotated as __rcu.
*/
#define rcu_dereference_check(p, c) \
__rcu_dereference_check((p), (c) || rcu_read_lock_held(), __rcu)
__rcu_dereference_check((p), __UNIQUE_ID(rcu), \
(c) || rcu_read_lock_held(), __rcu)
/**
* rcu_dereference_bh_check() - rcu_dereference_bh with debug checking
......@@ -541,7 +544,8 @@ do { \
* rcu_read_lock() but also rcu_read_lock_bh() into account.
*/
#define rcu_dereference_bh_check(p, c) \
__rcu_dereference_check((p), (c) || rcu_read_lock_bh_held(), __rcu)
__rcu_dereference_check((p), __UNIQUE_ID(rcu), \
(c) || rcu_read_lock_bh_held(), __rcu)
/**
* rcu_dereference_sched_check() - rcu_dereference_sched with debug checking
......@@ -556,7 +560,8 @@ do { \
* only rcu_read_lock() but also rcu_read_lock_sched() into account.
*/
#define rcu_dereference_sched_check(p, c) \
__rcu_dereference_check((p), (c) || rcu_read_lock_sched_held(), \
__rcu_dereference_check((p), __UNIQUE_ID(rcu), \
(c) || rcu_read_lock_sched_held(), \
__rcu)
/*
......@@ -566,7 +571,8 @@ do { \
* The no-tracing version of rcu_dereference_raw() must not call
* rcu_read_lock_held().
*/
#define rcu_dereference_raw_check(p) __rcu_dereference_check((p), 1, __rcu)
#define rcu_dereference_raw_check(p) \
__rcu_dereference_check((p), __UNIQUE_ID(rcu), 1, __rcu)
/**
* rcu_dereference_protected() - fetch RCU pointer when updates prevented
......@@ -585,7 +591,7 @@ do { \
* but very ugly failures.
*/
#define rcu_dereference_protected(p, c) \
__rcu_dereference_protected((p), (c), __rcu)
__rcu_dereference_protected((p), __UNIQUE_ID(rcu), (c), __rcu)
/**
......
include/linux/rcutiny.h
View file @ e7d38f16
......@@ -85,7 +85,7 @@ static inline void rcu_irq_enter_irqson(void) { }
static inline void rcu_irq_exit(void) { }
static inline void rcu_irq_exit_check_preempt(void) { }
#define rcu_is_idle_cpu(cpu) \
(is_idle_task(current) && !in_nmi() && !in_irq() && !in_serving_softirq())
(is_idle_task(current) && !in_nmi() && !in_hardirq() && !in_serving_softirq())
static inline void exit_rcu(void) { }
static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
{
......
include/linux/srcu.h
View file @ e7d38f16
......@@ -117,7 +117,8 @@ static inline int srcu_read_lock_held(const struct srcu_struct *ssp)
* lockdep_is_held() calls.
*/
#define srcu_dereference_check(p, ssp, c) \
__rcu_dereference_check((p), (c) || srcu_read_lock_held(ssp), __rcu)
__rcu_dereference_check((p), __UNIQUE_ID(rcu), \
(c) || srcu_read_lock_held(ssp), __rcu)
/**
* srcu_dereference - fetch SRCU-protected pointer for later dereferencing
......
include/linux/torture.h
View file @ e7d38f16
......@@ -38,13 +38,8 @@ do { \
pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); \
} \
} while (0)
#define VERBOSE_TOROUT_ERRSTRING(s) \
do { \
if (verbose) { \
verbose_torout_sleep(); \
pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); \
} \
} while (0)
#define TOROUT_ERRSTRING(s) \
pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s)
void verbose_torout_sleep(void);
#define torture_init_error(firsterr) \
......
kernel/locking/locktorture.c
View file @ e7d38f16
......@@ -1047,7 +1047,7 @@ static int __init lock_torture_init(void)
sizeof(writer_tasks[0]),
GFP_KERNEL);
if (writer_tasks == NULL) {
VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
TOROUT_ERRSTRING("writer_tasks: Out of memory");
firsterr = -ENOMEM;
goto unwind;
}
......@@ -1058,7 +1058,7 @@ static int __init lock_torture_init(void)
sizeof(reader_tasks[0]),
GFP_KERNEL);
if (reader_tasks == NULL) {
VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
TOROUT_ERRSTRING("reader_tasks: Out of memory");
kfree(writer_tasks);
writer_tasks = NULL;
firsterr = -ENOMEM;
......
kernel/rcu/Kconfig
View file @ e7d38f16
......@@ -112,7 +112,7 @@ config RCU_STALL_COMMON
making these warnings mandatory for the tree variants.
config RCU_NEED_SEGCBLIST
def_bool ( TREE_RCU || TREE_SRCU )
def_bool ( TREE_RCU || TREE_SRCU || TASKS_RCU_GENERIC )
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
......@@ -169,24 +169,6 @@ config RCU_FANOUT_LEAF
Take the default if unsure.
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
depends on NO_HZ_COMMON && SMP && RCU_EXPERT
default n
help
This option permits CPUs to enter dynticks-idle state even if
they have RCU callbacks queued, and prevents RCU from waking
these CPUs up more than roughly once every four jiffies (by
default, you can adjust this using the rcutree.rcu_idle_gp_delay
parameter), thus improving energy efficiency. On the other
hand, this option increases the duration of RCU grace periods,
for example, slowing down synchronize_rcu().
Say Y if energy efficiency is critically important, and you
don't care about increased grace-period durations.
Say N if you are unsure.
config RCU_BOOST
bool "Enable RCU priority boosting"
depends on (RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT) || PREEMPT_RT
......
kernel/rcu/rcu_segcblist.c
View file @ e7d38f16
......@@ -261,16 +261,14 @@ void rcu_segcblist_disable(struct rcu_segcblist *rsclp)
}
/*
* Mark the specified rcu_segcblist structure as offloaded.
* Mark the specified rcu_segcblist structure as offloaded (or not)
*/
void rcu_segcblist_offload(struct rcu_segcblist *rsclp, bool offload)
{
if (offload) {
rcu_segcblist_clear_flags(rsclp, SEGCBLIST_SOFTIRQ_ONLY);
rcu_segcblist_set_flags(rsclp, SEGCBLIST_OFFLOADED);
} else {
if (offload)
rcu_segcblist_set_flags(rsclp, SEGCBLIST_LOCKING | SEGCBLIST_OFFLOADED);
else
rcu_segcblist_clear_flags(rsclp, SEGCBLIST_OFFLOADED);
}
}
/*
......
kernel/rcu/rcu_segcblist.h
View file @ e7d38f16
......@@ -80,11 +80,14 @@ static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
return rcu_segcblist_test_flags(rsclp, SEGCBLIST_ENABLED);
}
/* Is the specified rcu_segcblist offloaded, or is SEGCBLIST_SOFTIRQ_ONLY set? */
/*
* Is the specified rcu_segcblist NOCB offloaded (or in the middle of the
* [de]offloading process)?
*/
static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
{
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
!rcu_segcblist_test_flags(rsclp, SEGCBLIST_SOFTIRQ_ONLY))
rcu_segcblist_test_flags(rsclp, SEGCBLIST_LOCKING))
return true;
return false;
......@@ -92,9 +95,8 @@ static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
static inline bool rcu_segcblist_completely_offloaded(struct rcu_segcblist *rsclp)
{
int flags = SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP | SEGCBLIST_OFFLOADED;
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) && (rsclp->flags & flags) == flags)
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
!rcu_segcblist_test_flags(rsclp, SEGCBLIST_RCU_CORE))
return true;
return false;
......
kernel/rcu/rcuscale.c
View file @ e7d38f16
......@@ -50,8 +50,8 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s)
#define VERBOSE_SCALEOUT_STRING(s) \
do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0)
#define VERBOSE_SCALEOUT_ERRSTRING(s) \
do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s); } while (0)
#define SCALEOUT_ERRSTRING(s) \
pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s)
/*
* The intended use cases for the nreaders and nwriters module parameters
......@@ -514,11 +514,11 @@ rcu_scale_cleanup(void)
* during the mid-boot phase, so have to wait till the end.
*/
if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
VERBOSE_SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
if (rcu_gp_is_normal() && gp_exp)
VERBOSE_SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
if (gp_exp && gp_async)
VERBOSE_SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!");
SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!");
if (torture_cleanup_begin())
return;
......@@ -845,7 +845,7 @@ rcu_scale_init(void)
reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
GFP_KERNEL);
if (reader_tasks == NULL) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
SCALEOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
......@@ -865,7 +865,7 @@ rcu_scale_init(void)
kcalloc(nrealwriters, sizeof(*writer_n_durations),
GFP_KERNEL);
if (!writer_tasks || !writer_durations || !writer_n_durations) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
SCALEOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
......
kernel/rcu/rcutorture.c
View file @ e7d38f16
This diff is collapsed.
kernel/rcu/refscale.c
View file @ e7d38f16
......@@ -44,7 +44,10 @@
pr_alert("%s" SCALE_FLAG s, scale_type, ## x)
#define VERBOSE_SCALEOUT(s, x...) \
do { if (verbose) pr_alert("%s" SCALE_FLAG s, scale_type, ## x); } while (0)
do { \
if (verbose) \
pr_alert("%s" SCALE_FLAG s "\n", scale_type, ## x); \
} while (0)
static atomic_t verbose_batch_ctr;
......@@ -54,12 +57,11 @@ do { \
(verbose_batched <= 0 || \
!(atomic_inc_return(&verbose_batch_ctr) % verbose_batched))) { \
schedule_timeout_uninterruptible(1); \
pr_alert("%s" SCALE_FLAG s, scale_type, ## x); \
pr_alert("%s" SCALE_FLAG s "\n", scale_type, ## x); \
} \
} while (0)
#define VERBOSE_SCALEOUT_ERRSTRING(s, x...) \
do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! " s, scale_type, ## x); } while (0)
#define SCALEOUT_ERRSTRING(s, x...) pr_alert("%s" SCALE_FLAG "!!! " s "\n", scale_type, ## x)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joel Fernandes (Google) <joel@joelfernandes.org>");
......@@ -604,7 +606,7 @@ static u64 process_durations(int n)
char *buf;
u64 sum = 0;
buf = kmalloc(128 + nreaders * 32, GFP_KERNEL);
buf = kmalloc(800 + 64, GFP_KERNEL);
if (!buf)
return 0;
buf[0] = 0;
......@@ -617,13 +619,15 @@ static u64 process_durations(int n)
if (i % 5 == 0)
strcat(buf, "\n");
if (strlen(buf) >= 800) {
pr_alert("%s", buf);
buf[0] = 0;
}
strcat(buf, buf1);
sum += rt->last_duration_ns;
}
strcat(buf, "\n");
SCALEOUT("%s\n", buf);
pr_alert("%s\n", buf);
kfree(buf);
return sum;
......@@ -637,7 +641,6 @@ static u64 process_durations(int n)
// point all the timestamps are printed.
static int main_func(void *arg)
{
bool errexit = false;
int exp, r;
char buf1[64];
char *buf;
......@@ -648,10 +651,10 @@ static int main_func(void *arg)
VERBOSE_SCALEOUT("main_func task started");
result_avg = kzalloc(nruns * sizeof(*result_avg), GFP_KERNEL);
buf = kzalloc(64 + nruns * 32, GFP_KERNEL);
buf = kzalloc(800 + 64, GFP_KERNEL);
if (!result_avg || !buf) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
errexit = true;
SCALEOUT_ERRSTRING("out of memory");
goto oom_exit;
}
if (holdoff)
schedule_timeout_interruptible(holdoff * HZ);
......@@ -663,8 +666,6 @@ static int main_func(void *arg)
// Start exp readers up per experiment
for (exp = 0; exp < nruns && !torture_must_stop(); exp++) {
if (errexit)
break;
if (torture_must_stop())
goto end;
......@@ -698,26 +699,23 @@ static int main_func(void *arg)
// Print the average of all experiments
SCALEOUT("END OF TEST. Calculating average duration per loop (nanoseconds)...\n");
if (!errexit) {
buf[0] = 0;
strcat(buf, "\n");
strcat(buf, "Runs\tTime(ns)\n");
}
pr_alert("Runs\tTime(ns)\n");
for (exp = 0; exp < nruns; exp++) {
u64 avg;
u32 rem;
if (errexit)
break;
avg = div_u64_rem(result_avg[exp], 1000, &rem);
sprintf(buf1, "%d\t%llu.%03u\n", exp + 1, avg, rem);
strcat(buf, buf1);
if (strlen(buf) >= 800) {
pr_alert("%s", buf);
buf[0] = 0;
}
}
if (!errexit)
SCALEOUT("%s", buf);
pr_alert("%s", buf);
oom_exit:
// This will shutdown everything including us.
if (shutdown) {
shutdown_start = 1;
......@@ -841,12 +839,12 @@ ref_scale_init(void)
reader_tasks = kcalloc(nreaders, sizeof(reader_tasks[0]),
GFP_KERNEL);
if (!reader_tasks) {
VERBOSE_SCALEOUT_ERRSTRING("out of memory");
SCALEOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
VERBOSE_SCALEOUT("Starting %d reader threads\n", nreaders);
VERBOSE_SCALEOUT("Starting %d reader threads", nreaders);
for (i = 0; i < nreaders; i++) {
firsterr = torture_create_kthread(ref_scale_reader, (void *)i,
......
kernel/rcu/srcutiny.c
View file @ e7d38f16
......@@ -99,7 +99,7 @@ void __srcu_read_unlock(struct srcu_struct *ssp, int idx)
int newval = READ_ONCE(ssp->srcu_lock_nesting[idx]) - 1;
WRITE_ONCE(ssp->srcu_lock_nesting[idx], newval);
if (!newval && READ_ONCE(ssp->srcu_gp_waiting))
if (!newval && READ_ONCE(ssp->srcu_gp_waiting) && in_task())
swake_up_one(&ssp->srcu_wq);
}
EXPORT_SYMBOL_GPL(__srcu_read_unlock);
......
kernel/rcu/tasks.h
View file @ e7d38f16
This diff is collapsed.
kernel/rcu/tree.c
View file @ e7d38f16
This diff is collapsed.
kernel/rcu/tree.h
View file @ e7d38f16
......@@ -157,7 +157,6 @@ struct rcu_data {
bool core_needs_qs; /* Core waits for quiescent state. */
bool beenonline; /* CPU online at least once. */
bool gpwrap; /* Possible ->gp_seq wrap. */
bool exp_deferred_qs; /* This CPU awaiting a deferred QS? */
bool cpu_started; /* RCU watching this onlining CPU. */
struct rcu_node *mynode; /* This CPU's leaf of hierarchy */
unsigned long grpmask; /* Mask to apply to leaf qsmask. */
......@@ -189,11 +188,6 @@ struct rcu_data {
bool rcu_urgent_qs; /* GP old need light quiescent state. */
bool rcu_forced_tick; /* Forced tick to provide QS. */
bool rcu_forced_tick_exp; /* ... provide QS to expedited GP. */
#ifdef CONFIG_RCU_FAST_NO_HZ
unsigned long last_accelerate; /* Last jiffy CBs were accelerated. */
unsigned long last_advance_all; /* Last jiffy CBs were all advanced. */
int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
/* 4) rcu_barrier(), OOM callbacks, and expediting. */
struct rcu_head barrier_head;
......@@ -227,8 +221,11 @@ struct rcu_data {
struct swait_queue_head nocb_gp_wq; /* For nocb kthreads to sleep on. */
bool nocb_cb_sleep; /* Is the nocb CB thread asleep? */
struct task_struct *nocb_cb_kthread;
struct rcu_data *nocb_next_cb_rdp;
/* Next rcu_data in wakeup chain. */
struct list_head nocb_head_rdp; /*
* Head of rcu_data list in wakeup chain,
* if rdp_gp.
*/
struct list_head nocb_entry_rdp; /* rcu_data node in wakeup chain. */
/* The following fields are used by CB kthread, hence new cacheline. */
struct rcu_data *nocb_gp_rdp ____cacheline_internodealigned_in_smp;
......@@ -419,8 +416,6 @@ static bool rcu_is_callbacks_kthread(void);
static void rcu_cpu_kthread_setup(unsigned int cpu);
static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp);
static void __init rcu_spawn_boost_kthreads(void);
static void rcu_cleanup_after_idle(void);
static void rcu_prepare_for_idle(void);
static bool rcu_preempt_has_tasks(struct rcu_node *rnp);
static bool rcu_preempt_need_deferred_qs(struct task_struct *t);
static void rcu_preempt_deferred_qs(struct task_struct *t);
......@@ -447,12 +442,16 @@ static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp,
static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp);
#ifdef CONFIG_RCU_NOCB_CPU
static void __init rcu_organize_nocb_kthreads(void);
#define rcu_nocb_lock_irqsave(rdp, flags) \
do { \
if (!rcu_segcblist_is_offloaded(&(rdp)->cblist)) \
local_irq_save(flags); \
else \
raw_spin_lock_irqsave(&(rdp)->nocb_lock, (flags)); \
/*
* Disable IRQs before checking offloaded state so that local
* locking is safe against concurrent de-offloading.
*/
#define rcu_nocb_lock_irqsave(rdp, flags) \
do { \
local_irq_save(flags); \
if (rcu_segcblist_is_offloaded(&(rdp)->cblist)) \
raw_spin_lock(&(rdp)->nocb_lock); \
} while (0)
#else /* #ifdef CONFIG_RCU_NOCB_CPU */
#define rcu_nocb_lock_irqsave(rdp, flags) local_irq_save(flags)
......
kernel/rcu/tree_exp.h
View file @ e7d38f16
......@@ -255,7 +255,7 @@ static void rcu_report_exp_cpu_mult(struct rcu_node *rnp,
*/
static void rcu_report_exp_rdp(struct rcu_data *rdp)
{
WRITE_ONCE(rdp->exp_deferred_qs, false);
WRITE_ONCE(rdp->cpu_no_qs.b.exp, false);
rcu_report_exp_cpu_mult(rdp->mynode, rdp->grpmask, true);
}
......@@ -387,6 +387,7 @@ static void sync_rcu_exp_select_node_cpus(struct work_struct *wp)
continue;
}
if (get_cpu() == cpu) {
mask_ofl_test |= mask;
put_cpu();
continue;
}
......@@ -506,7 +507,10 @@ static void synchronize_rcu_expedited_wait(void)
if (rdp->rcu_forced_tick_exp)
continue;
rdp->rcu_forced_tick_exp = true;
tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
preempt_disable();
if (cpu_online(cpu))
tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
preempt_enable();
}
}
j = READ_ONCE(jiffies_till_first_fqs);
......@@ -655,7 +659,7 @@ static void rcu_exp_handler(void *unused)
rcu_dynticks_curr_cpu_in_eqs()) {
rcu_report_exp_rdp(rdp);
} else {
rdp->exp_deferred_qs = true;
WRITE_ONCE(rdp->cpu_no_qs.b.exp, true);
set_tsk_need_resched(t);
set_preempt_need_resched();
}
......@@ -677,7 +681,7 @@ static void rcu_exp_handler(void *unused)
if (depth > 0) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (rnp->expmask & rdp->grpmask) {
rdp->exp_deferred_qs = true;
WRITE_ONCE(rdp->cpu_no_qs.b.exp, true);
t->rcu_read_unlock_special.b.exp_hint = true;
}
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
......@@ -759,7 +763,7 @@ static void sync_sched_exp_online_cleanup(int cpu)
my_cpu = get_cpu();
/* Quiescent state either not needed or already requested, leave. */
if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) ||
rdp->cpu_no_qs.b.exp) {
READ_ONCE(rdp->cpu_no_qs.b.exp)) {
put_cpu();
return;
}
......
kernel/rcu/tree_nocb.h
View file @ e7d38f16
This diff is collapsed.
kernel/rcu/tree_plugin.h
View file @ e7d38f16
This diff is collapsed.
kernel/rcu/tree_stall.h
View file @ e7d38f16
......@@ -347,26 +347,6 @@ static void rcu_dump_cpu_stacks(void)
}
}
#ifdef CONFIG_RCU_FAST_NO_HZ
static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
{
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
sprintf(cp, "last_accelerate: %04lx/%04lx dyntick_enabled: %d",
rdp->last_accelerate & 0xffff, jiffies & 0xffff,
!!rdp->tick_nohz_enabled_snap);
}
#else /* #ifdef CONFIG_RCU_FAST_NO_HZ */
static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
{
*cp = '\0';
}
#endif /* #else #ifdef CONFIG_RCU_FAST_NO_HZ */
static const char * const gp_state_names[] = {
[RCU_GP_IDLE] = "RCU_GP_IDLE",
[RCU_GP_WAIT_GPS] = "RCU_GP_WAIT_GPS",
......@@ -408,13 +388,12 @@ static bool rcu_is_gp_kthread_starving(unsigned long *jp)
* of RCU grace periods that this CPU is ignorant of, for example, "1"
* if the CPU was aware of the previous grace period.
*
* Also print out idle and (if CONFIG_RCU_FAST_NO_HZ) idle-entry info.
* Also print out idle info.
*/
static void print_cpu_stall_info(int cpu)
{
unsigned long delta;
bool falsepositive;
char fast_no_hz[72];
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
char *ticks_title;
unsigned long ticks_value;
......@@ -432,11 +411,10 @@ static void print_cpu_stall_info(int cpu)
ticks_title = "ticks this GP";
ticks_value = rdp->ticks_this_gp;
}
print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq);
falsepositive = rcu_is_gp_kthread_starving(NULL) &&
rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp));
pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s%s\n",
pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%#lx softirq=%u/%u fqs=%ld %s\n",
cpu,
"O."[!!cpu_online(cpu)],
"o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],
......@@ -449,7 +427,6 @@ static void print_cpu_stall_info(int cpu)
rdp->dynticks_nesting, rdp->dynticks_nmi_nesting,
rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu),
data_race(rcu_state.n_force_qs) - rcu_state.n_force_qs_gpstart,
fast_no_hz,
falsepositive ? " (false positive?)" : "");
}
......
kernel/scftorture.c
View file @ e7d38f16
......@@ -38,14 +38,10 @@
#define SCFTORT_STRING "scftorture"
#define SCFTORT_FLAG SCFTORT_STRING ": "
#define SCFTORTOUT(s, x...) \
pr_alert(SCFTORT_FLAG s, ## x)
#define VERBOSE_SCFTORTOUT(s, x...) \
do { if (verbose) pr_alert(SCFTORT_FLAG s, ## x); } while (0)
do { if (verbose) pr_alert(SCFTORT_FLAG s "\n", ## x); } while (0)
#define VERBOSE_SCFTORTOUT_ERRSTRING(s, x...) \
do { if (verbose) pr_alert(SCFTORT_FLAG "!!! " s, ## x); } while (0)
#define SCFTORTOUT_ERRSTRING(s, x...) pr_alert(SCFTORT_FLAG "!!! " s "\n", ## x)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>");
......@@ -587,14 +583,14 @@ static int __init scf_torture_init(void)
if (weight_resched1 == 0 && weight_single1 == 0 && weight_single_rpc1 == 0 &&
weight_single_wait1 == 0 && weight_many1 == 0 && weight_many_wait1 == 0 &&
weight_all1 == 0 && weight_all_wait1 == 0) {
VERBOSE_SCFTORTOUT_ERRSTRING("all zero weights makes no sense");
SCFTORTOUT_ERRSTRING("all zero weights makes no sense");
firsterr = -EINVAL;
goto unwind;
}
if (IS_BUILTIN(CONFIG_SCF_TORTURE_TEST))
scf_sel_add(weight_resched1, SCF_PRIM_RESCHED, false);
else if (weight_resched1)
VERBOSE_SCFTORTOUT_ERRSTRING("built as module, weight_resched ignored");
SCFTORTOUT_ERRSTRING("built as module, weight_resched ignored");
scf_sel_add(weight_single1, SCF_PRIM_SINGLE, false);
scf_sel_add(weight_single_rpc1, SCF_PRIM_SINGLE_RPC, true);
scf_sel_add(weight_single_wait1, SCF_PRIM_SINGLE, true);
......@@ -625,12 +621,12 @@ static int __init scf_torture_init(void)
nthreads = num_online_cpus();
scf_stats_p = kcalloc(nthreads, sizeof(scf_stats_p[0]), GFP_KERNEL);
if (!scf_stats_p) {
VERBOSE_SCFTORTOUT_ERRSTRING("out of memory");
SCFTORTOUT_ERRSTRING("out of memory");
firsterr = -ENOMEM;
goto unwind;
}
VERBOSE_SCFTORTOUT("Starting %d smp_call_function() threads\n", nthreads);
VERBOSE_SCFTORTOUT("Starting %d smp_call_function() threads", nthreads);
atomic_set(&n_started, nthreads);
for (i = 0; i < nthreads; i++) {
......
kernel/torture.c
View file @ e7d38f16
......@@ -570,7 +570,7 @@ int torture_shuffle_init(long shuffint)
shuffle_idle_cpu = -1;
if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask");
TOROUT_ERRSTRING("Failed to alloc mask");
return -ENOMEM;
}
......@@ -934,7 +934,7 @@ int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
*tp = kthread_run(fn, arg, "%s", s);
if (IS_ERR(*tp)) {
ret = PTR_ERR(*tp);
VERBOSE_TOROUT_ERRSTRING(f);
TOROUT_ERRSTRING(f);
*tp = NULL;
}
torture_shuffle_task_register(*tp);
......
tools/include/nolibc/nolibc.h
View file @ e7d38f16
This diff is collapsed.
tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
View file @ e7d38f16
......@@ -30,9 +30,9 @@ editor=${EDITOR-vi}
files=
for i in ${rundir}/*/Make.out
do
if egrep -q "error:|warning:" < $i
if egrep -q "error:|warning:|^ld: .*undefined reference to" < $i
then
egrep "error:|warning:" < $i > $i.diags
egrep "error:|warning:|^ld: .*undefined reference to" < $i > $i.diags
files="$files $i.diags $i"
fi
done
......
tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
View file @ e7d38f16
......@@ -25,7 +25,7 @@ stopstate="`grep 'End-test grace-period state: g' $i/console.log 2> /dev/null |
tail -1 | sed -e 's/^\[[ 0-9.]*] //' |
awk '{ print \"[\" $1 \" \" $5 \" \" $6 \" \" $7 \"]\"; }' |
tr -d '\012\015'`"
fwdprog="`grep 'rcu_torture_fwd_prog_cr Duration' $i/console.log 2> /dev/null | sed -e 's/^\[[^]]*] //' | sort -k15nr | head -1 | awk '{ print $14 " " $15 }'`"
fwdprog="`grep 'rcu_torture_fwd_prog n_max_cbs: ' $i/console.log 2> /dev/null | sed -e 's/^\[[^]]*] //' | sort -k3nr | head -1 | awk '{ print $2 " " $3 }'`"
if test -z "$ngps"
then
echo "$configfile ------- " $stopstate
......
tools/testing/selftests/rcutorture/bin/kvm-remote.sh
View file @ e7d38f16
......@@ -144,7 +144,7 @@ do
if test "$ret" -ne 0
then
echo System $i unreachable, giving up. | tee -a "$oldrun/remote-log"
exit 4 | tee -a "$oldrun/remote-log"
exit 4
fi
done
......@@ -157,8 +157,15 @@ do
ret=$?
if test "$ret" -ne 0
then
echo Unable to download $T/binres.tgz to system $i, giving up. | tee -a "$oldrun/remote-log"
exit 10 | tee -a "$oldrun/remote-log"
echo Unable to download $T/binres.tgz to system $i, waiting and then retrying. | tee -a "$oldrun/remote-log"
sleep 60
cat $T/binres.tgz | ssh $i "cd /tmp; tar -xzf -"
ret=$?
if test "$ret" -ne 0
then
echo Unable to download $T/binres.tgz to system $i, giving up. | tee -a "$oldrun/remote-log"
exit 10
fi
fi
done
......@@ -177,16 +184,16 @@ checkremotefile () {
ret=$?
if test "$ret" -eq 255
then
echo " ---" ssh failure to $1 checking for file $2, retry after $sleeptime seconds. `date`
echo " ---" ssh failure to $1 checking for file $2, retry after $sleeptime seconds. `date` | tee -a "$oldrun/remote-log"
elif test "$ret" -eq 0
then
return 0
elif test "$ret" -eq 1
then
echo " ---" File \"$2\" not found: ssh $1 test -f \"$2\"
echo " ---" File \"$2\" not found: ssh $1 test -f \"$2\" | tee -a "$oldrun/remote-log"
return 1
else
echo " ---" Exit code $ret: ssh $1 test -f \"$2\", retry after $sleeptime seconds. `date`
echo " ---" Exit code $ret: ssh $1 test -f \"$2\", retry after $sleeptime seconds. `date` | tee -a "$oldrun/remote-log"
return $ret
fi
sleep $sleeptime
......@@ -245,7 +252,7 @@ do
sleep 30
fi
done
echo All batches started. `date`
echo All batches started. `date` | tee -a "$oldrun/remote-log"
# Wait for all remaining scenarios to complete and collect results.
for i in $systems
......@@ -254,7 +261,7 @@ do
do
sleep 30
done
echo " ---" Collecting results from $i `date`
echo " ---" Collecting results from $i `date` | tee -a "$oldrun/remote-log"
( cd "$oldrun"; ssh $i "cd $rundir; tar -czf - kvm-remote-*.sh.out */console.log */kvm-test-1-run*.sh.out */qemu[_-]pid */qemu-retval */qemu-affinity; rm -rf $T > /dev/null 2>&1" | tar -xzf - )
done
......
tools/testing/selftests/rcutorture/bin/kvm.sh
View file @ e7d38f16
......@@ -74,7 +74,9 @@ usage () {
echo " --help"
echo " --interactive"
echo " --jitter N [ maxsleep (us) [ maxspin (us) ] ]"
echo " --kasan"
echo " --kconfig Kconfig-options"
echo " --kcsan"
echo " --kmake-arg kernel-make-arguments"
echo " --mac nn:nn:nn:nn:nn:nn"
echo " --memory megabytes|nnnG"
......@@ -83,6 +85,7 @@ usage () {
echo " --qemu-cmd qemu-system-..."
echo " --remote"
echo " --results absolute-pathname"
echo " --shutdown-grace seconds"
echo " --torture lock|rcu|rcuscale|refscale|scf"
echo " --trust-make"
exit 1
......@@ -175,14 +178,14 @@ do
jitter="$2"
shift
;;
--kasan)
TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
;;
--kconfig|--kconfigs)
checkarg --kconfig "(Kconfig options)" $# "$2" '^CONFIG_[A-Z0-9_]\+=\([ynm]\|[0-9]\+\)\( CONFIG_[A-Z0-9_]\+=\([ynm]\|[0-9]\+\)\)*$' '^error$'
TORTURE_KCONFIG_ARG="`echo "$TORTURE_KCONFIG_ARG $2" | sed -e 's/^ *//' -e 's/ *$//'`"
shift
;;
--kasan)
TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
;;
--kcsan)
TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_STRICT=y CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y"; export TORTURE_KCONFIG_KCSAN_ARG
;;
......
tools/testing/selftests/rcutorture/bin/parse-build.sh
View file @ e7d38f16
......@@ -39,7 +39,8 @@ fi
grep warning: < $F > $T/warnings
grep "include/linux/*rcu*\.h:" $T/warnings > $T/hwarnings
grep "kernel/rcu/[^/]*:" $T/warnings > $T/cwarnings
cat $T/hwarnings $T/cwarnings > $T/rcuwarnings
grep "^ld: .*undefined reference to" $T/warnings | head -1 > $T/ldwarnings
cat $T/hwarnings $T/cwarnings $T/ldwarnings > $T/rcuwarnings
if test -s $T/rcuwarnings
then
print_warning $title build errors:
......
tools/testing/selftests/rcutorture/configs/rcu/SRCU-T
View file @ e7d38f16
......@@ -2,6 +2,7 @@ CONFIG_SMP=n
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PREEMPT_DYNAMIC=n
#CHECK#CONFIG_TINY_SRCU=y
CONFIG_RCU_TRACE=n
CONFIG_DEBUG_LOCK_ALLOC=y
......
tools/testing/selftests/rcutorture/configs/rcu/SRCU-U
View file @ e7d38f16
......@@ -2,6 +2,7 @@ CONFIG_SMP=n
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PREEMPT_DYNAMIC=n
#CHECK#CONFIG_TINY_SRCU=y
CONFIG_RCU_TRACE=n
CONFIG_DEBUG_LOCK_ALLOC=n
......
tools/testing/selftests/rcutorture/configs/rcu/TASKS01.boot
View file @ e7d38f16
rcutorture.torture_type=tasks
rcutree.use_softirq=0
rcupdate.rcu_task_enqueue_lim=4
tools/testing/selftests/rcutorture/configs/rcu/TINY01
View file @ e7d38f16
......@@ -2,6 +2,7 @@ CONFIG_SMP=n
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PREEMPT_DYNAMIC=n
#CHECK#CONFIG_TINY_RCU=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
......
tools/testing/selftests/rcutorture/configs/rcu/TINY02
View file @ e7d38f16
......@@ -2,6 +2,7 @@ CONFIG_SMP=n
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PREEMPT_DYNAMIC=n
#CHECK#CONFIG_TINY_RCU=y
CONFIG_HZ_PERIODIC=y
CONFIG_NO_HZ_IDLE=n
......
tools/testing/selftests/rcutorture/configs/rcu/TRACE01.boot
View file @ e7d38f16
rcutorture.torture_type=tasks-tracing
rcupdate.rcu_task_enqueue_lim=2
tools/testing/selftests/rcutorture/configs/rcu/TRACE02.boot
View file @ e7d38f16
rcutorture.torture_type=tasks-tracing
rcutorture.fwd_progress=2
tools/testing/selftests/rcutorture/configs/rcu/TREE01
View file @ e7d38f16
......@@ -6,7 +6,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=y
CONFIG_RCU_TRACE=y
CONFIG_HOTPLUG_CPU=y
CONFIG_MAXSMP=y
......
tools/testing/selftests/rcutorture/configs/rcu/TREE02
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_RCU_FANOUT=3
CONFIG_RCU_FANOUT_LEAF=3
......
tools/testing/selftests/rcutorture/configs/rcu/TREE04
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=n
CONFIG_NO_HZ_FULL=y
CONFIG_RCU_FAST_NO_HZ=y
CONFIG_RCU_TRACE=y
CONFIG_RCU_FANOUT=4
CONFIG_RCU_FANOUT_LEAF=3
......
tools/testing/selftests/rcutorture/configs/rcu/TREE05
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_HOTPLUG_CPU=y
CONFIG_RCU_FANOUT=6
......
tools/testing/selftests/rcutorture/configs/rcu/TREE06
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_RCU_FANOUT=6
CONFIG_RCU_FANOUT_LEAF=6
......
tools/testing/selftests/rcutorture/configs/rcu/TREE07
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=n
CONFIG_NO_HZ_FULL=y
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=y
CONFIG_HOTPLUG_CPU=y
CONFIG_RCU_FANOUT=2
......
tools/testing/selftests/rcutorture/configs/rcu/TREE08
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_RCU_FANOUT=3
CONFIG_RCU_FANOUT_LEAF=2
......
tools/testing/selftests/rcutorture/configs/rcu/TREE10
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
......
tools/testing/selftests/rcutorture/configs/rcuscale/TINY
View file @ e7d38f16
......@@ -2,11 +2,11 @@ CONFIG_SMP=n
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PREEMPT_DYNAMIC=n
#CHECK#CONFIG_TINY_RCU=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_PROVE_LOCKING=n
......
tools/testing/selftests/rcutorture/configs/rcuscale/TRACE01
View file @ e7d38f16
......@@ -5,7 +5,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_PROVE_LOCKING=n
......
tools/testing/selftests/rcutorture/configs/rcuscale/TREE
View file @ e7d38f16
......@@ -6,7 +6,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_HOTPLUG_CPU=y
CONFIG_SUSPEND=n
CONFIG_HIBERNATION=n
......
tools/testing/selftests/rcutorture/configs/rcuscale/TREE54
View file @ e7d38f16
......@@ -7,7 +7,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_HOTPLUG_CPU=y
CONFIG_SUSPEND=n
CONFIG_HIBERNATION=n
......
tools/testing/selftests/rcutorture/configs/refscale/NOPREEMPT
View file @ e7d38f16
......@@ -6,7 +6,6 @@ CONFIG_PREEMPT=n
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_HOTPLUG_CPU=y
CONFIG_SUSPEND=n
CONFIG_HIBERNATION=n
......
tools/testing/selftests/rcutorture/configs/refscale/PREEMPT
View file @ e7d38f16
......@@ -6,7 +6,6 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_HOTPLUG_CPU=y
CONFIG_SUSPEND=n
CONFIG_HIBERNATION=n
......
tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
View file @ e7d38f16
......@@ -15,7 +15,6 @@ CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.
CONFIG_RCU_BOOST -- one of PREEMPT_RCU.
CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.
CONFIG_RCU_FANOUT_LEAF -- Do one non-default.
CONFIG_RCU_FAST_NO_HZ -- Do one, but not with all nohz_full CPUs.
CONFIG_RCU_NOCB_CPU -- Do three, one with no rcu_nocbs CPUs, one with
rcu_nocbs=0, and one with all rcu_nocbs CPUs.
CONFIG_RCU_TRACE -- Do half.
......
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