Skip to content

L
linux
Commit 31945aa9 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files
Options

Merge branches 'doc.2017.01.15b', 'dyntick.2017.01.23a', 'fixes.2017.01.23a',... 

Merge branches 'doc.2017.01.15b', 'dyntick.2017.01.23a', 'fixes.2017.01.23a', 'srcu.2017.01.25a' and 'torture.2017.01.15b' into HEAD

doc.2017.01.15b: Documentation updates
dyntick.2017.01.23a: Dyntick tracking consolidation
fixes.2017.01.23a: Miscellaneous fixes
srcu.2017.01.25a: SRCU rewrite, fixes, and verification
torture.2017.01.15b: Torture-test updates
parents e3c50dfb 38d30b33 8dc79888 7f554a3d 7d025948
Show whitespace changes
Inline Side-by-side
Showing with 2005 additions and 258 deletions
Documentation/RCU/trace.txt
View file @ 31945aa9
......@@ -237,7 +237,7 @@ o "ktl" is the low-order 16 bits (in hexadecimal) of the count of
The output of "cat rcu/rcu_preempt/rcuexp" looks as follows:
s=21872 wd1=0 wd2=0 wd3=5 n=0 enq=0 sc=21872
s=21872 wd1=0 wd2=0 wd3=5 enq=0 sc=21872
These fields are as follows:
......@@ -249,9 +249,6 @@ o "wd1", "wd2", and "wd3" are the number of times that an attempt
completed an expedited grace period that satisfies the attempted
request. "Our work is done."
o "n" is number of times that a concurrent CPU-hotplug operation
forced a fallback to a normal grace period.
o "enq" is the number of quiescent states still outstanding.
o "sc" is the number of times that the attempt to start a
......
include/linux/llist.h
View file @ 31945aa9
......@@ -3,28 +3,33 @@
/*
* Lock-less NULL terminated single linked list
*
* If there are multiple producers and multiple consumers, llist_add
* can be used in producers and llist_del_all can be used in
* consumers. They can work simultaneously without lock. But
* llist_del_first can not be used here. Because llist_del_first
* depends on list->first->next does not changed if list->first is not
* changed during its operation, but llist_del_first, llist_add,
* llist_add (or llist_del_all, llist_add, llist_add) sequence in
* another consumer may violate that.
*
* If there are multiple producers and one consumer, llist_add can be
* used in producers and llist_del_all or llist_del_first can be used
* in the consumer.
*
* This can be summarized as follow:
* Cases where locking is not needed:
* If there are multiple producers and multiple consumers, llist_add can be
* used in producers and llist_del_all can be used in consumers simultaneously
* without locking. Also a single consumer can use llist_del_first while
* multiple producers simultaneously use llist_add, without any locking.
*
* Cases where locking is needed:
* If we have multiple consumers with llist_del_first used in one consumer, and
* llist_del_first or llist_del_all used in other consumers, then a lock is
* needed. This is because llist_del_first depends on list->first->next not
* changing, but without lock protection, there's no way to be sure about that
* if a preemption happens in the middle of the delete operation and on being
* preempted back, the list->first is the same as before causing the cmpxchg in
* llist_del_first to succeed. For example, while a llist_del_first operation
* is in progress in one consumer, then a llist_del_first, llist_add,
* llist_add (or llist_del_all, llist_add, llist_add) sequence in another
* consumer may cause violations.
*
* This can be summarized as follows:
*
* | add | del_first | del_all
* add | - | - | -
* del_first | | L | L
* del_all | | | -
*
* Where "-" stands for no lock is needed, while "L" stands for lock
* is needed.
* Where, a particular row's operation can happen concurrently with a column's
* operation, with "-" being no lock needed, while "L" being lock is needed.
*
* The list entries deleted via llist_del_all can be traversed with
* traversing function such as llist_for_each etc. But the list
......
include/linux/rcupdate.h
View file @ 31945aa9
......@@ -1161,5 +1161,17 @@ do { \
ftrace_dump(oops_dump_mode); \
} while (0)
/*
* Place this after a lock-acquisition primitive to guarantee that
* an UNLOCK+LOCK pair acts as a full barrier. This guarantee applies
* if the UNLOCK and LOCK are executed by the same CPU or if the
* UNLOCK and LOCK operate on the same lock variable.
*/
#ifdef CONFIG_PPC
#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */
#else /* #ifdef CONFIG_PPC */
#define smp_mb__after_unlock_lock() do { } while (0)
#endif /* #else #ifdef CONFIG_PPC */
#endif /* __LINUX_RCUPDATE_H */
include/linux/rcutiny.h
View file @ 31945aa9
......@@ -27,6 +27,12 @@
#include <linux/cache.h>
struct rcu_dynticks;
static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp)
{
return 0;
}
static inline unsigned long get_state_synchronize_rcu(void)
{
return 0;
......
include/linux/srcu.h
View file @ 31945aa9
......@@ -33,9 +33,9 @@
#include <linux/rcupdate.h>
#include <linux/workqueue.h>
struct srcu_struct_array {
unsigned long c[2];
unsigned long seq[2];
struct srcu_array {
unsigned long lock_count[2];
unsigned long unlock_count[2];
};
struct rcu_batch {
......@@ -46,7 +46,7 @@ struct rcu_batch {
struct srcu_struct {
unsigned long completed;
struct srcu_struct_array __percpu *per_cpu_ref;
struct srcu_array __percpu *per_cpu_ref;
spinlock_t queue_lock; /* protect ->batch_queue, ->running */
bool running;
/* callbacks just queued */
......@@ -118,7 +118,7 @@ void process_srcu(struct work_struct *work);
* See include/linux/percpu-defs.h for the rules on per-CPU variables.
*/
#define __DEFINE_SRCU(name, is_static) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
static DEFINE_PER_CPU(struct srcu_array, name##_srcu_array);\
is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name)
#define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */)
#define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static)
......
include/trace/events/rcu.h
View file @ 31945aa9
......@@ -385,11 +385,11 @@ TRACE_EVENT(rcu_quiescent_state_report,
/*
* Tracepoint for quiescent states detected by force_quiescent_state().
* These trace events include the type of RCU, the grace-period number
* that was blocked by the CPU, the CPU itself, and the type of quiescent
* state, which can be "dti" for dyntick-idle mode, "ofl" for CPU offline,
* or "kick" when kicking a CPU that has been in dyntick-idle mode for
* too long.
* These trace events include the type of RCU, the grace-period number that
* was blocked by the CPU, the CPU itself, and the type of quiescent state,
* which can be "dti" for dyntick-idle mode, "ofl" for CPU offline, "kick"
* when kicking a CPU that has been in dyntick-idle mode for too long, or
* "rqc" if the CPU got a quiescent state via its rcu_qs_ctr.
*/
TRACE_EVENT(rcu_fqs,
......
init/Kconfig
View file @ 31945aa9
......@@ -529,7 +529,6 @@ config SRCU
config TASKS_RCU
bool
default n
depends on !UML
select SRCU
help
This option enables a task-based RCU implementation that uses
......@@ -781,19 +780,6 @@ config RCU_NOCB_CPU_ALL
endchoice
config RCU_EXPEDITE_BOOT
bool
default n
help
This option enables expedited grace periods at boot time,
as if rcu_expedite_gp() had been invoked early in boot.
The corresponding rcu_unexpedite_gp() is invoked from
rcu_end_inkernel_boot(), which is intended to be invoked
at the end of the kernel-only boot sequence, just before
init is exec'ed.
Accept the default if unsure.
endmenu # "RCU Subsystem"
config BUILD_BIN2C
......
kernel/locking/lockdep.c
View file @ 31945aa9
......@@ -4412,13 +4412,13 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
#endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */
/* Note: the following can be executed concurrently, so be careful. */
printk("\n");
printk("===============================\n");
printk("[ INFO: suspicious RCU usage. ]\n");
pr_err("===============================\n");
pr_err("[ ERR: suspicious RCU usage. ]\n");
print_kernel_ident();
printk("-------------------------------\n");
printk("%s:%d %s!\n", file, line, s);
printk("\nother info that might help us debug this:\n\n");
printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
pr_err("-------------------------------\n");
pr_err("%s:%d %s!\n", file, line, s);
pr_err("\nother info that might help us debug this:\n\n");
pr_err("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
!rcu_lockdep_current_cpu_online()
? "RCU used illegally from offline CPU!\n"
: !rcu_is_watching()
......
kernel/locking/locktorture.c
View file @ 31945aa9
......@@ -780,6 +780,10 @@ static void lock_torture_cleanup(void)
else
lock_torture_print_module_parms(cxt.cur_ops,
"End of test: SUCCESS");
kfree(cxt.lwsa);
kfree(cxt.lrsa);
end:
torture_cleanup_end();
}
......@@ -924,6 +928,8 @@ static int __init lock_torture_init(void)
GFP_KERNEL);
if (reader_tasks == NULL) {
VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
kfree(writer_tasks);
writer_tasks = NULL;
firsterr = -ENOMEM;
goto unwind;
}
......
kernel/membarrier.c
View file @ 31945aa9
......@@ -16,6 +16,7 @@
#include <linux/syscalls.h>
#include <linux/membarrier.h>
#include <linux/tick.h>
/*
* Bitmask made from a "or" of all commands within enum membarrier_cmd,
......@@ -51,6 +52,9 @@
*/
SYSCALL_DEFINE2(membarrier, int, cmd, int, flags)
{
/* MEMBARRIER_CMD_SHARED is not compatible with nohz_full. */
if (tick_nohz_full_enabled())
return -ENOSYS;
if (unlikely(flags))
return -EINVAL;
switch (cmd) {
......
kernel/rcu/rcutorture.c
View file @ 31945aa9
......@@ -564,10 +564,25 @@ static void srcu_torture_stats(void)
pr_alert("%s%s per-CPU(idx=%d):",
torture_type, TORTURE_FLAG, idx);
for_each_possible_cpu(cpu) {
unsigned long l0, l1;
unsigned long u0, u1;
long c0, c1;
struct srcu_array *counts = per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu);
c0 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[!idx];
c1 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[idx];
u0 = counts->unlock_count[!idx];
u1 = counts->unlock_count[idx];
/*
* Make sure that a lock is always counted if the corresponding
* unlock is counted.
*/
smp_rmb();
l0 = counts->lock_count[!idx];
l1 = counts->lock_count[idx];
c0 = l0 - u0;
c1 = l1 - u1;
pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
}
pr_cont("\n");
......
kernel/rcu/srcu.c
View file @ 31945aa9
......@@ -106,7 +106,7 @@ static int init_srcu_struct_fields(struct srcu_struct *sp)
rcu_batch_init(&sp->batch_check1);
rcu_batch_init(&sp->batch_done);
INIT_DELAYED_WORK(&sp->work, process_srcu);
sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
sp->per_cpu_ref = alloc_percpu(struct srcu_array);
return sp->per_cpu_ref ? 0 : -ENOMEM;
}
......@@ -141,114 +141,77 @@ EXPORT_SYMBOL_GPL(init_srcu_struct);
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
/*
* Returns approximate total of the readers' ->seq[] values for the
* Returns approximate total of the readers' ->lock_count[] values for the
* rank of per-CPU counters specified by idx.
*/
static unsigned long srcu_readers_seq_idx(struct srcu_struct *sp, int idx)
static unsigned long srcu_readers_lock_idx(struct srcu_struct *sp, int idx)
{
int cpu;
unsigned long sum = 0;
unsigned long t;
for_each_possible_cpu(cpu) {
t = READ_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->seq[idx]);
sum += t;
struct srcu_array *cpuc = per_cpu_ptr(sp->per_cpu_ref, cpu);
sum += READ_ONCE(cpuc->lock_count[idx]);
}
return sum;
}
/*
* Returns approximate number of readers active on the specified rank
* of the per-CPU ->c[] counters.
* Returns approximate total of the readers' ->unlock_count[] values for the
* rank of per-CPU counters specified by idx.
*/
static unsigned long srcu_readers_active_idx(struct srcu_struct *sp, int idx)
static unsigned long srcu_readers_unlock_idx(struct srcu_struct *sp, int idx)
{
int cpu;
unsigned long sum = 0;
unsigned long t;
for_each_possible_cpu(cpu) {
t = READ_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[idx]);
sum += t;
struct srcu_array *cpuc = per_cpu_ptr(sp->per_cpu_ref, cpu);
sum += READ_ONCE(cpuc->unlock_count[idx]);
}
return sum;
}
/*
* Return true if the number of pre-existing readers is determined to
* be stably zero. An example unstable zero can occur if the call
* to srcu_readers_active_idx() misses an __srcu_read_lock() increment,
* but due to task migration, sees the corresponding __srcu_read_unlock()
* decrement. This can happen because srcu_readers_active_idx() takes
* time to sum the array, and might in fact be interrupted or preempted
* partway through the summation.
* be zero.
*/
static bool srcu_readers_active_idx_check(struct srcu_struct *sp, int idx)
{
unsigned long seq;
unsigned long unlocks;
seq = srcu_readers_seq_idx(sp, idx);
unlocks = srcu_readers_unlock_idx(sp, idx);
/*
* The following smp_mb() A pairs with the smp_mb() B located in
* __srcu_read_lock(). This pairing ensures that if an
* __srcu_read_lock() increments its counter after the summation
* in srcu_readers_active_idx(), then the corresponding SRCU read-side
* critical section will see any changes made prior to the start
* of the current SRCU grace period.
* Make sure that a lock is always counted if the corresponding unlock
* is counted. Needs to be a smp_mb() as the read side may contain a
* read from a variable that is written to before the synchronize_srcu()
* in the write side. In this case smp_mb()s A and B act like the store
* buffering pattern.
*
* Also, if the above call to srcu_readers_seq_idx() saw the
* increment of ->seq[], then the call to srcu_readers_active_idx()
* must see the increment of ->c[].
* This smp_mb() also pairs with smp_mb() C to prevent accesses after the
* synchronize_srcu() from being executed before the grace period ends.
*/
smp_mb(); /* A */
/*
* Note that srcu_readers_active_idx() can incorrectly return
* zero even though there is a pre-existing reader throughout.
* To see this, suppose that task A is in a very long SRCU
* read-side critical section that started on CPU 0, and that
* no other reader exists, so that the sum of the counters
* is equal to one. Then suppose that task B starts executing
* srcu_readers_active_idx(), summing up to CPU 1, and then that
* task C starts reading on CPU 0, so that its increment is not
* summed, but finishes reading on CPU 2, so that its decrement
* -is- summed. Then when task B completes its sum, it will
* incorrectly get zero, despite the fact that task A has been
* in its SRCU read-side critical section the whole time.
*
* We therefore do a validation step should srcu_readers_active_idx()
* return zero.
*/
if (srcu_readers_active_idx(sp, idx) != 0)
return false;
/*
* The remainder of this function is the validation step.
* The following smp_mb() D pairs with the smp_mb() C in
* __srcu_read_unlock(). If the __srcu_read_unlock() was seen
* by srcu_readers_active_idx() above, then any destructive
* operation performed after the grace period will happen after
* the corresponding SRCU read-side critical section.
* If the locks are the same as the unlocks, then there must have
* been no readers on this index at some time in between. This does not
* mean that there are no more readers, as one could have read the
* current index but not have incremented the lock counter yet.
*
* Note that there can be at most NR_CPUS worth of readers using
* the old index, which is not enough to overflow even a 32-bit
* integer. (Yes, this does mean that systems having more than
* a billion or so CPUs need to be 64-bit systems.) Therefore,
* the sum of the ->seq[] counters cannot possibly overflow.
* Therefore, the only way that the return values of the two
* calls to srcu_readers_seq_idx() can be equal is if there were
* no increments of the corresponding rank of ->seq[] counts
* in the interim. But the missed-increment scenario laid out
* above includes an increment of the ->seq[] counter by
* the corresponding __srcu_read_lock(). Therefore, if this
* scenario occurs, the return values from the two calls to
* srcu_readers_seq_idx() will differ, and thus the validation
* step below suffices.
*/
smp_mb(); /* D */
return srcu_readers_seq_idx(sp, idx) == seq;
* Possible bug: There is no guarantee that there haven't been ULONG_MAX
* increments of ->lock_count[] since the unlocks were counted, meaning
* that this could return true even if there are still active readers.
* Since there are no memory barriers around srcu_flip(), the CPU is not
* required to increment ->completed before running
* srcu_readers_unlock_idx(), which means that there could be an
* arbitrarily large number of critical sections that execute after
* srcu_readers_unlock_idx() but use the old value of ->completed.
*/
return srcu_readers_lock_idx(sp, idx) == unlocks;
}
/**
......@@ -266,8 +229,12 @@ static bool srcu_readers_active(struct srcu_struct *sp)
unsigned long sum = 0;
for_each_possible_cpu(cpu) {
sum += READ_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[0]);
sum += READ_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[1]);
struct srcu_array *cpuc = per_cpu_ptr(sp->per_cpu_ref, cpu);
sum += READ_ONCE(cpuc->lock_count[0]);
sum += READ_ONCE(cpuc->lock_count[1]);
sum -= READ_ONCE(cpuc->unlock_count[0]);
sum -= READ_ONCE(cpuc->unlock_count[1]);
}
return sum;
}
......@@ -298,9 +265,8 @@ int __srcu_read_lock(struct srcu_struct *sp)
int idx;
idx = READ_ONCE(sp->completed) & 0x1;
__this_cpu_inc(sp->per_cpu_ref->c[idx]);
__this_cpu_inc(sp->per_cpu_ref->lock_count[idx]);
smp_mb(); /* B */ /* Avoid leaking the critical section. */
__this_cpu_inc(sp->per_cpu_ref->seq[idx]);
return idx;
}
EXPORT_SYMBOL_GPL(__srcu_read_lock);
......@@ -314,7 +280,7 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock);
void __srcu_read_unlock(struct srcu_struct *sp, int idx)
{
smp_mb(); /* C */ /* Avoid leaking the critical section. */
this_cpu_dec(sp->per_cpu_ref->c[idx]);
this_cpu_inc(sp->per_cpu_ref->unlock_count[idx]);
}
EXPORT_SYMBOL_GPL(__srcu_read_unlock);
......@@ -349,12 +315,21 @@ static bool try_check_zero(struct srcu_struct *sp, int idx, int trycount)
/*
* Increment the ->completed counter so that future SRCU readers will
* use the other rank of the ->c[] and ->seq[] arrays. This allows
* use the other rank of the ->(un)lock_count[] arrays. This allows
* us to wait for pre-existing readers in a starvation-free manner.
*/
static void srcu_flip(struct srcu_struct *sp)
{
sp->completed++;
WRITE_ONCE(sp->completed, sp->completed + 1);
/*
* Ensure that if the updater misses an __srcu_read_unlock()
* increment, that task's next __srcu_read_lock() will see the
* above counter update. Note that both this memory barrier
* and the one in srcu_readers_active_idx_check() provide the
* guarantee for __srcu_read_lock().
*/
smp_mb(); /* D */ /* Pairs with C. */
}
/*
......@@ -392,6 +367,7 @@ void call_srcu(struct srcu_struct *sp, struct rcu_head *head,
head->next = NULL;
head->func = func;
spin_lock_irqsave(&sp->queue_lock, flags);
smp_mb__after_unlock_lock(); /* Caller's prior accesses before GP. */
rcu_batch_queue(&sp->batch_queue, head);
if (!sp->running) {
sp->running = true;
......@@ -425,6 +401,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount)
head->next = NULL;
head->func = wakeme_after_rcu;
spin_lock_irq(&sp->queue_lock);
smp_mb__after_unlock_lock(); /* Caller's prior accesses before GP. */
if (!sp->running) {
/* steal the processing owner */
sp->running = true;
......@@ -444,8 +421,11 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount)
spin_unlock_irq(&sp->queue_lock);
}
if (!done)
if (!done) {
wait_for_completion(&rcu.completion);
smp_mb(); /* Caller's later accesses after GP. */
}
}
/**
......@@ -613,7 +593,8 @@ static void srcu_advance_batches(struct srcu_struct *sp, int trycount)
/*
* Invoke a limited number of SRCU callbacks that have passed through
* their grace period. If there are more to do, SRCU will reschedule
* the workqueue.
* the workqueue. Note that needed memory barriers have been executed
* in this task's context by srcu_readers_active_idx_check().
*/
static void srcu_invoke_callbacks(struct srcu_struct *sp)
{
......
kernel/rcu/tiny.c
View file @ 31945aa9
......@@ -41,8 +41,6 @@
/* Forward declarations for tiny_plugin.h. */
struct rcu_ctrlblk;
static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp);
static void rcu_process_callbacks(struct softirq_action *unused);
static void __call_rcu(struct rcu_head *head,
rcu_callback_t func,
struct rcu_ctrlblk *rcp);
......
kernel/rcu/tree.c
View file @ 31945aa9
......@@ -281,6 +281,116 @@ static DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
#endif /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
};
/*
* Record entry into an extended quiescent state. This is only to be
* called when not already in an extended quiescent state.
*/
static void rcu_dynticks_eqs_enter(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
int special;
/*
* CPUs seeing atomic_inc_return() must see prior RCU read-side
* critical sections, and we also must force ordering with the
* next idle sojourn.
*/
special = atomic_inc_return(&rdtp->dynticks);
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && special & 0x1);
}
/*
* Record exit from an extended quiescent state. This is only to be
* called from an extended quiescent state.
*/
static void rcu_dynticks_eqs_exit(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
int special;
/*
* CPUs seeing atomic_inc_return() must see prior idle sojourns,
* and we also must force ordering with the next RCU read-side
* critical section.
*/
special = atomic_inc_return(&rdtp->dynticks);
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !(special & 0x1));
}
/*
* Reset the current CPU's ->dynticks counter to indicate that the
* newly onlined CPU is no longer in an extended quiescent state.
* This will either leave the counter unchanged, or increment it
* to the next non-quiescent value.
*
* The non-atomic test/increment sequence works because the upper bits
* of the ->dynticks counter are manipulated only by the corresponding CPU,
* or when the corresponding CPU is offline.
*/
static void rcu_dynticks_eqs_online(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
if (atomic_read(&rdtp->dynticks) & 0x1)
return;
atomic_add(0x1, &rdtp->dynticks);
}
/*
* Is the current CPU in an extended quiescent state?
*
* No ordering, as we are sampling CPU-local information.
*/
bool rcu_dynticks_curr_cpu_in_eqs(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
return !(atomic_read(&rdtp->dynticks) & 0x1);
}
/*
* Snapshot the ->dynticks counter with full ordering so as to allow
* stable comparison of this counter with past and future snapshots.
*/
int rcu_dynticks_snap(struct rcu_dynticks *rdtp)
{
int snap = atomic_add_return(0, &rdtp->dynticks);
return snap;
}
/*
* Return true if the snapshot returned from rcu_dynticks_snap()
* indicates that RCU is in an extended quiescent state.
*/
static bool rcu_dynticks_in_eqs(int snap)
{
return !(snap & 0x1);
}
/*
* Return true if the CPU corresponding to the specified rcu_dynticks
* structure has spent some time in an extended quiescent state since
* rcu_dynticks_snap() returned the specified snapshot.
*/
static bool rcu_dynticks_in_eqs_since(struct rcu_dynticks *rdtp, int snap)
{
return snap != rcu_dynticks_snap(rdtp);
}
/*
* Do a double-increment of the ->dynticks counter to emulate a
* momentary idle-CPU quiescent state.
*/
static void rcu_dynticks_momentary_idle(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
int special = atomic_add_return(2, &rdtp->dynticks);
/* It is illegal to call this from idle state. */
WARN_ON_ONCE(!(special & 0x1));
}
DEFINE_PER_CPU_SHARED_ALIGNED(unsigned long, rcu_qs_ctr);
EXPORT_PER_CPU_SYMBOL_GPL(rcu_qs_ctr);
......@@ -300,7 +410,6 @@ EXPORT_PER_CPU_SYMBOL_GPL(rcu_qs_ctr);
static void rcu_momentary_dyntick_idle(void)
{
struct rcu_data *rdp;
struct rcu_dynticks *rdtp;
int resched_mask;
struct rcu_state *rsp;
......@@ -327,10 +436,7 @@ static void rcu_momentary_dyntick_idle(void)
* quiescent state, with no need for this CPU to do anything
* further.
*/
rdtp = this_cpu_ptr(&rcu_dynticks);
smp_mb__before_atomic(); /* Earlier stuff before QS. */
atomic_add(2, &rdtp->dynticks); /* QS. */
smp_mb__after_atomic(); /* Later stuff after QS. */
rcu_dynticks_momentary_idle();
break;
}
}
......@@ -611,7 +717,7 @@ static int
cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
{
return &rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL] &&
rdp->nxttail[RCU_DONE_TAIL] != NULL;
rdp->nxttail[RCU_NEXT_TAIL] != NULL;
}
/*
......@@ -673,7 +779,7 @@ static void rcu_eqs_enter_common(long long oldval, bool user)
{
struct rcu_state *rsp;
struct rcu_data *rdp;
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
RCU_TRACE(struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);)
trace_rcu_dyntick(TPS("Start"), oldval, rdtp->dynticks_nesting);
if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
......@@ -692,12 +798,7 @@ static void rcu_eqs_enter_common(long long oldval, bool user)
do_nocb_deferred_wakeup(rdp);
}
rcu_prepare_for_idle();
/* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
smp_mb__before_atomic(); /* See above. */
atomic_inc(&rdtp->dynticks);
smp_mb__after_atomic(); /* Force ordering with next sojourn. */
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
atomic_read(&rdtp->dynticks) & 0x1);
rcu_dynticks_eqs_enter();
rcu_dynticks_task_enter();
/*
......@@ -826,15 +927,10 @@ void rcu_irq_exit_irqson(void)
*/
static void rcu_eqs_exit_common(long long oldval, int user)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
RCU_TRACE(struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);)
rcu_dynticks_task_exit();
smp_mb__before_atomic(); /* Force ordering w/previous sojourn. */
atomic_inc(&rdtp->dynticks);
/* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
smp_mb__after_atomic(); /* See above. */
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
!(atomic_read(&rdtp->dynticks) & 0x1));
rcu_dynticks_eqs_exit();
rcu_cleanup_after_idle();
trace_rcu_dyntick(TPS("End"), oldval, rdtp->dynticks_nesting);
if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
......@@ -980,12 +1076,8 @@ void rcu_nmi_enter(void)
* to be in the outermost NMI handler that interrupted an RCU-idle
* period (observation due to Andy Lutomirski).
*/
if (!(atomic_read(&rdtp->dynticks) & 0x1)) {
smp_mb__before_atomic(); /* Force delay from prior write. */
atomic_inc(&rdtp->dynticks);
/* atomic_inc() before later RCU read-side crit sects */
smp_mb__after_atomic(); /* See above. */
WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
if (rcu_dynticks_curr_cpu_in_eqs()) {
rcu_dynticks_eqs_exit();
incby = 1;
}
rdtp->dynticks_nmi_nesting += incby;
......@@ -1010,7 +1102,7 @@ void rcu_nmi_exit(void)
* to us!)
*/
WARN_ON_ONCE(rdtp->dynticks_nmi_nesting <= 0);
WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
WARN_ON_ONCE(rcu_dynticks_curr_cpu_in_eqs());
/*
* If the nesting level is not 1, the CPU wasn't RCU-idle, so
......@@ -1023,11 +1115,7 @@ void rcu_nmi_exit(void)
/* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */
rdtp->dynticks_nmi_nesting = 0;
/* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
smp_mb__before_atomic(); /* See above. */
atomic_inc(&rdtp->dynticks);
smp_mb__after_atomic(); /* Force delay to next write. */
WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
rcu_dynticks_eqs_enter();
}
/**
......@@ -1040,7 +1128,7 @@ void rcu_nmi_exit(void)
*/
bool notrace __rcu_is_watching(void)
{
return atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1;
return !rcu_dynticks_curr_cpu_in_eqs();
}
/**
......@@ -1123,9 +1211,9 @@ static int rcu_is_cpu_rrupt_from_idle(void)
static int dyntick_save_progress_counter(struct rcu_data *rdp,
bool *isidle, unsigned long *maxj)
{
rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
rdp->dynticks_snap = rcu_dynticks_snap(rdp->dynticks);
rcu_sysidle_check_cpu(rdp, isidle, maxj);
if ((rdp->dynticks_snap & 0x1) == 0) {
if (rcu_dynticks_in_eqs(rdp->dynticks_snap)) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4,
rdp->mynode->gpnum))
......@@ -1144,12 +1232,10 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp,
static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
bool *isidle, unsigned long *maxj)
{
unsigned int curr;
unsigned long jtsq;
int *rcrmp;
unsigned int snap;
curr = (unsigned int)atomic_add_return(0, &rdp->dynticks->dynticks);
snap = (unsigned int)rdp->dynticks_snap;
unsigned long rjtsc;
struct rcu_node *rnp;
/*
* If the CPU passed through or entered a dynticks idle phase with
......@@ -1159,27 +1245,39 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
* read-side critical section that started before the beginning
* of the current RCU grace period.
*/
if ((curr & 0x1) == 0 || UINT_CMP_GE(curr, snap + 2)) {
if (rcu_dynticks_in_eqs_since(rdp->dynticks, rdp->dynticks_snap)) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
rdp->dynticks_fqs++;
return 1;
}
/* Compute and saturate jiffies_till_sched_qs. */
jtsq = jiffies_till_sched_qs;
rjtsc = rcu_jiffies_till_stall_check();
if (jtsq > rjtsc / 2) {
WRITE_ONCE(jiffies_till_sched_qs, rjtsc);
jtsq = rjtsc / 2;
} else if (jtsq < 1) {
WRITE_ONCE(jiffies_till_sched_qs, 1);
jtsq = 1;
}
/*
* Check for the CPU being offline, but only if the grace period
* is old enough. We don't need to worry about the CPU changing
* state: If we see it offline even once, it has been through a
* quiescent state.
*
* The reason for insisting that the grace period be at least
* one jiffy old is that CPUs that are not quite online and that
* have just gone offline can still execute RCU read-side critical
* sections.
* Has this CPU encountered a cond_resched_rcu_qs() since the
* beginning of the grace period? For this to be the case,
* the CPU has to have noticed the current grace period. This
* might not be the case for nohz_full CPUs looping in the kernel.
*/
if (ULONG_CMP_GE(rdp->rsp->gp_start + 2, jiffies))
return 0; /* Grace period is not old enough. */
barrier();
if (cpu_is_offline(rdp->cpu)) {
rnp = rdp->mynode;
if (time_after(jiffies, rdp->rsp->gp_start + jtsq) &&
READ_ONCE(rdp->rcu_qs_ctr_snap) != per_cpu(rcu_qs_ctr, rdp->cpu) &&
READ_ONCE(rdp->gpnum) == rnp->gpnum && !rdp->gpwrap) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("rqc"));
return 1;
}
/* Check for the CPU being offline. */
if (!(rdp->grpmask & rcu_rnp_online_cpus(rnp))) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("ofl"));
rdp->offline_fqs++;
return 1;
......@@ -1207,9 +1305,8 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
* warning delay.
*/
rcrmp = &per_cpu(rcu_sched_qs_mask, rdp->cpu);
if (ULONG_CMP_GE(jiffies,
rdp->rsp->gp_start + jiffies_till_sched_qs) ||
ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
if (time_after(jiffies, rdp->rsp->gp_start + jtsq) ||
time_after(jiffies, rdp->rsp->jiffies_resched)) {
if (!(READ_ONCE(*rcrmp) & rdp->rsp->flavor_mask)) {
WRITE_ONCE(rdp->cond_resched_completed,
READ_ONCE(rdp->mynode->completed));
......@@ -1220,11 +1317,12 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */
}
/* And if it has been a really long time, kick the CPU as well. */
if (ULONG_CMP_GE(jiffies,
rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) ||
ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs))
resched_cpu(rdp->cpu); /* Force CPU into scheduler. */
/*
* If more than halfway to RCU CPU stall-warning time, do
* a resched_cpu() to try to loosen things up a bit.
*/
if (jiffies - rdp->rsp->gp_start > rcu_jiffies_till_stall_check() / 2)
resched_cpu(rdp->cpu);
return 0;
}
......@@ -1277,7 +1375,10 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp)
}
/*
* Dump stacks of all tasks running on stalled CPUs.
* Dump stacks of all tasks running on stalled CPUs. First try using
* NMIs, but fall back to manual remote stack tracing on architectures
* that don't support NMI-based stack dumps. The NMI-triggered stack
* traces are more accurate because they are printed by the target CPU.
*/
static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
{
......@@ -1287,11 +1388,10 @@ static void rcu_dump_cpu_stacks(struct rcu_state *rsp)
rcu_for_each_leaf_node(rsp, rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (rnp->qsmask != 0) {
for_each_leaf_node_possible_cpu(rnp, cpu)
if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu))
if (!trigger_single_cpu_backtrace(cpu))
dump_cpu_task(cpu);
}
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
}
......@@ -1379,6 +1479,9 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
(long)rsp->gpnum, (long)rsp->completed, totqlen);
if (ndetected) {
rcu_dump_cpu_stacks(rsp);
/* Complain about tasks blocking the grace period. */
rcu_print_detail_task_stall(rsp);
} else {
if (READ_ONCE(rsp->gpnum) != gpnum ||
READ_ONCE(rsp->completed) == gpnum) {
......@@ -1395,9 +1498,6 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
}
}
/* Complain about tasks blocking the grace period. */
rcu_print_detail_task_stall(rsp);
rcu_check_gp_kthread_starvation(rsp);
panic_on_rcu_stall();
......@@ -2467,10 +2567,8 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
rnp = rdp->mynode;
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if ((rdp->cpu_no_qs.b.norm &&
rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) ||
rdp->gpnum != rnp->gpnum || rnp->completed == rnp->gpnum ||
rdp->gpwrap) {
if (rdp->cpu_no_qs.b.norm || rdp->gpnum != rnp->gpnum ||
rnp->completed == rnp->gpnum || rdp->gpwrap) {
/*
* The grace period in which this quiescent state was
......@@ -2525,8 +2623,7 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
* Was there a quiescent state since the beginning of the grace
* period? If no, then exit and wait for the next call.
*/
if (rdp->cpu_no_qs.b.norm &&
rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr))
if (rdp->cpu_no_qs.b.norm)
return;
/*
......@@ -3480,9 +3577,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
rdp->core_needs_qs && rdp->cpu_no_qs.b.norm &&
rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) {
rdp->n_rp_core_needs_qs++;
} else if (rdp->core_needs_qs &&
(!rdp->cpu_no_qs.b.norm ||
rdp->rcu_qs_ctr_snap != __this_cpu_read(rcu_qs_ctr))) {
} else if (rdp->core_needs_qs && !rdp->cpu_no_qs.b.norm) {
rdp->n_rp_report_qs++;
return 1;
}
......@@ -3748,7 +3843,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE);
WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp->dynticks)));
rdp->cpu = cpu;
rdp->rsp = rsp;
rcu_boot_init_nocb_percpu_data(rdp);
......@@ -3765,7 +3860,6 @@ static void
rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
unsigned long mask;
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_node *rnp = rcu_get_root(rsp);
......@@ -3778,8 +3872,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
init_callback_list(rdp); /* Re-enable callbacks on this CPU. */
rdp->dynticks->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
rcu_sysidle_init_percpu_data(rdp->dynticks);
atomic_set(&rdp->dynticks->dynticks,
(atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1);
rcu_dynticks_eqs_online();
raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
/*
......@@ -3788,7 +3881,6 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
* of the next grace period.
*/
rnp = rdp->mynode;
mask = rdp->grpmask;
raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */
if (!rdp->beenonline)
WRITE_ONCE(rsp->ncpus, READ_ONCE(rsp->ncpus) + 1);
......@@ -3872,7 +3964,7 @@ void rcu_cpu_starting(unsigned int cpu)
struct rcu_state *rsp;
for_each_rcu_flavor(rsp) {
rdp = this_cpu_ptr(rsp->rda);
rdp = per_cpu_ptr(rsp->rda, cpu);
rnp = rdp->mynode;
mask = rdp->grpmask;
raw_spin_lock_irqsave_rcu_node(rnp, flags);
......
kernel/rcu/tree.h
View file @ 31945aa9
......@@ -521,7 +521,6 @@ struct rcu_state {
struct mutex exp_mutex; /* Serialize expedited GP. */
struct mutex exp_wake_mutex; /* Serialize wakeup. */
unsigned long expedited_sequence; /* Take a ticket. */
atomic_long_t expedited_normal; /* # fallbacks to normal. */
atomic_t expedited_need_qs; /* # CPUs left to check in. */
struct swait_queue_head expedited_wq; /* Wait for check-ins. */
int ncpus_snap; /* # CPUs seen last time. */
......@@ -595,6 +594,8 @@ extern struct rcu_state rcu_bh_state;
extern struct rcu_state rcu_preempt_state;
#endif /* #ifdef CONFIG_PREEMPT_RCU */
int rcu_dynticks_snap(struct rcu_dynticks *rdtp);
#ifdef CONFIG_RCU_BOOST
DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu);
......@@ -687,18 +688,6 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
}
#endif /* #ifdef CONFIG_RCU_TRACE */
/*
* Place this after a lock-acquisition primitive to guarantee that
* an UNLOCK+LOCK pair act as a full barrier. This guarantee applies
* if the UNLOCK and LOCK are executed by the same CPU or if the
* UNLOCK and LOCK operate on the same lock variable.
*/
#ifdef CONFIG_PPC
#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */
#else /* #ifdef CONFIG_PPC */
#define smp_mb__after_unlock_lock() do { } while (0)
#endif /* #else #ifdef CONFIG_PPC */
/*
* Wrappers for the rcu_node::lock acquire and release.
*
......
kernel/rcu/tree_exp.h
View file @ 31945aa9
......@@ -20,16 +20,26 @@
* Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
*/
/* Wrapper functions for expedited grace periods. */
/*
* Record the start of an expedited grace period.
*/
static void rcu_exp_gp_seq_start(struct rcu_state *rsp)
{
rcu_seq_start(&rsp->expedited_sequence);
}
/*
* Record the end of an expedited grace period.
*/
static void rcu_exp_gp_seq_end(struct rcu_state *rsp)
{
rcu_seq_end(&rsp->expedited_sequence);
smp_mb(); /* Ensure that consecutive grace periods serialize. */
}
/*
* Take a snapshot of the expedited-grace-period counter.
*/
static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp)
{
unsigned long s;
......@@ -39,6 +49,12 @@ static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp)
trace_rcu_exp_grace_period(rsp->name, s, TPS("snap"));
return s;
}
/*
* Given a counter snapshot from rcu_exp_gp_seq_snap(), return true
* if a full expedited grace period has elapsed since that snapshot
* was taken.
*/
static bool rcu_exp_gp_seq_done(struct rcu_state *rsp, unsigned long s)
{
return rcu_seq_done(&rsp->expedited_sequence, s);
......@@ -356,12 +372,11 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
mask_ofl_test = 0;
for_each_leaf_node_possible_cpu(rnp, cpu) {
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
rdp->exp_dynticks_snap =
atomic_add_return(0, &rdtp->dynticks);
rcu_dynticks_snap(rdp->dynticks);
if (raw_smp_processor_id() == cpu ||
!(rdp->exp_dynticks_snap & 0x1) ||
rcu_dynticks_in_eqs(rdp->exp_dynticks_snap) ||
!(rnp->qsmaskinitnext & rdp->grpmask))
mask_ofl_test |= rdp->grpmask;
}
......@@ -380,13 +395,12 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
for_each_leaf_node_possible_cpu(rnp, cpu) {
unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
if (!(mask_ofl_ipi & mask))
continue;
retry_ipi:
if (atomic_add_return(0, &rdtp->dynticks) !=
rdp->exp_dynticks_snap) {
if (rcu_dynticks_in_eqs_since(rdp->dynticks,
rdp->exp_dynticks_snap)) {
mask_ofl_test |= mask;
continue;
}
......@@ -623,6 +637,11 @@ void synchronize_sched_expedited(void)
{
struct rcu_state *rsp = &rcu_sched_state;
RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) ||
lock_is_held(&rcu_lock_map) ||
lock_is_held(&rcu_sched_lock_map),
"Illegal synchronize_sched_expedited() in RCU read-side critical section");
/* If only one CPU, this is automatically a grace period. */
if (rcu_blocking_is_gp())
return;
......@@ -692,6 +711,11 @@ void synchronize_rcu_expedited(void)
{
struct rcu_state *rsp = rcu_state_p;
RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) ||
lock_is_held(&rcu_lock_map) ||
lock_is_held(&rcu_sched_lock_map),
"Illegal synchronize_rcu_expedited() in RCU read-side critical section");
if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE)
return;
_synchronize_rcu_expedited(rsp, sync_rcu_exp_handler);
......
kernel/rcu/tree_plugin.h
View file @ 31945aa9
......@@ -1643,7 +1643,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
"o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],
"N."[!!(rdp->grpmask & rdp->mynode->qsmaskinitnext)],
ticks_value, ticks_title,
atomic_read(&rdtp->dynticks) & 0xfff,
rcu_dynticks_snap(rdtp) & 0xfff,
rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting,
rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu),
READ_ONCE(rsp->n_force_qs) - rsp->n_force_qs_gpstart,
......@@ -2366,8 +2366,9 @@ static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp)
}
/*
* Each pass through this loop sets up one rcu_data structure and
* spawns one rcu_nocb_kthread().
* Each pass through this loop sets up one rcu_data structure.
* Should the corresponding CPU come online in the future, then
* we will spawn the needed set of rcu_nocb_kthread() kthreads.
*/
for_each_cpu(cpu, rcu_nocb_mask) {
rdp = per_cpu_ptr(rsp->rda, cpu);
......
kernel/rcu/tree_trace.c
View file @ 31945aa9
......@@ -124,7 +124,7 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu),
rdp->core_needs_qs);
seq_printf(m, " dt=%d/%llx/%d df=%lu",
atomic_read(&rdp->dynticks->dynticks),
rcu_dynticks_snap(rdp->dynticks),
rdp->dynticks->dynticks_nesting,
rdp->dynticks->dynticks_nmi_nesting,
rdp->dynticks_fqs);
......@@ -194,9 +194,8 @@ static int show_rcuexp(struct seq_file *m, void *v)
s2 += atomic_long_read(&rdp->exp_workdone2);
s3 += atomic_long_read(&rdp->exp_workdone3);
}
seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n",
seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu enq=%d sc=%lu\n",
rsp->expedited_sequence, s0, s1, s2, s3,
atomic_long_read(&rsp->expedited_normal),
atomic_read(&rsp->expedited_need_qs),
rsp->expedited_sequence / 2);
return 0;
......
kernel/rcu/update.c
View file @ 31945aa9
......@@ -132,8 +132,7 @@ bool rcu_gp_is_normal(void)
}
EXPORT_SYMBOL_GPL(rcu_gp_is_normal);
static atomic_t rcu_expedited_nesting =
ATOMIC_INIT(IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT) ? 1 : 0);
static atomic_t rcu_expedited_nesting = ATOMIC_INIT(1);
/*
* Should normal grace-period primitives be expedited? Intended for
......@@ -182,7 +181,6 @@ EXPORT_SYMBOL_GPL(rcu_unexpedite_gp);
*/
void rcu_end_inkernel_boot(void)
{
if (IS_ENABLED(CONFIG_RCU_EXPEDITE_BOOT))
rcu_unexpedite_gp();
if (rcu_normal_after_boot)
WRITE_ONCE(rcu_normal, 1);
......
lib/Kconfig.debug
View file @ 31945aa9
......@@ -1450,6 +1450,7 @@ config RCU_CPU_STALL_TIMEOUT
config RCU_TRACE
bool "Enable tracing for RCU"
depends on DEBUG_KERNEL
default y if TREE_RCU
select TRACE_CLOCK
help
This option provides tracing in RCU which presents stats
......
tools/testing/selftests/rcutorture/configs/rcu/CFcommon
View file @ 31945aa9
CONFIG_RCU_TORTURE_TEST=y
CONFIG_PRINTK_TIME=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TINY01
View file @ 31945aa9
......@@ -7,6 +7,7 @@ CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_TRACE=n
#CHECK#CONFIG_RCU_STALL_COMMON=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PREEMPT_COUNT=n
tools/testing/selftests/rcutorture/configs/rcu/TINY02
View file @ 31945aa9
......@@ -8,7 +8,8 @@ CONFIG_NO_HZ_IDLE=n
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_TRACE=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU_REPEATEDLY=y
#CHECK#CONFIG_PROVE_RCU=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_PREEMPT_COUNT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE01
View file @ 31945aa9
......@@ -16,3 +16,6 @@ CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE02
View file @ 31945aa9
......@@ -20,3 +20,7 @@ CONFIG_PROVE_LOCKING=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
tools/testing/selftests/rcutorture/configs/rcu/TREE03
View file @ 31945aa9
......@@ -17,3 +17,6 @@ CONFIG_RCU_BOOST=y
CONFIG_RCU_KTHREAD_PRIO=2
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE04
View file @ 31945aa9
......@@ -19,3 +19,7 @@ CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
CONFIG_RCU_EQS_DEBUG=y
tools/testing/selftests/rcutorture/configs/rcu/TREE05
View file @ 31945aa9
......@@ -19,3 +19,6 @@ CONFIG_PROVE_LOCKING=y
#CHECK#CONFIG_PROVE_RCU=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE06
View file @ 31945aa9
......@@ -20,3 +20,6 @@ CONFIG_PROVE_LOCKING=y
#CHECK#CONFIG_PROVE_RCU=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE07
View file @ 31945aa9
......@@ -19,3 +19,6 @@ CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP=y
CONFIG_RCU_TORTURE_TEST_SLOW_INIT=y
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT=y
tools/testing/selftests/rcutorture/configs/rcu/TREE08
View file @ 31945aa9
......@@ -17,8 +17,8 @@ CONFIG_RCU_FANOUT_LEAF=2
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_ALL=y
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_PROVE_LOCKING=y
#CHECK#CONFIG_PROVE_RCU=y
CONFIG_PROVE_LOCKING=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_RCU_EXPERT=y
CONFIG_RCU_EQS_DEBUG=y
tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
View file @ 31945aa9
......@@ -14,6 +14,7 @@ CONFIG_NO_HZ_FULL_SYSIDLE -- Do one.
CONFIG_PREEMPT -- Do half. (First three and #8.)
CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not.
CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.
CONFIG_PROVE_RCU_REPEATEDLY -- Do one.
CONFIG_RCU_BOOST -- one of PREEMPT_RCU.
CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing.
CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.
......@@ -25,7 +26,12 @@ CONFIG_RCU_NOCB_CPU_NONE -- Do one.
CONFIG_RCU_NOCB_CPU_ZERO -- Do one.
CONFIG_RCU_TRACE -- Do half.
CONFIG_SMP -- Need one !SMP for PREEMPT_RCU.
!RCU_EXPERT -- Do a few, but these have to be vanilla configurations.
CONFIG_RCU_EXPERT=n -- Do a few, but these have to be vanilla configurations.
CONFIG_RCU_EQS_DEBUG -- Do at least one for CONFIG_NO_HZ_FULL and not.
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP -- Do for all but a couple TREE scenarios.
CONFIG_RCU_TORTURE_TEST_SLOW_INIT -- Do for all but a couple TREE scenarios.
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT -- Do for all but a couple TREE scenarios.
RCU-bh: Do one with PREEMPT and one with !PREEMPT.
RCU-sched: Do one with PREEMPT but not BOOST.
......@@ -72,7 +78,30 @@ CONFIG_RCU_TORTURE_TEST_RUNNABLE
Always used in KVM testing.
CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT_DELAY
CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY
CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY
Inspection suffices, ignore.
CONFIG_PREEMPT_RCU
CONFIG_TREE_RCU
CONFIG_TINY_RCU
These are controlled by CONFIG_PREEMPT and/or CONFIG_SMP.
CONFIG_SPARSE_RCU_POINTER
Makes sense only for sparse runs, not for kernel builds.
CONFIG_SRCU
CONFIG_TASKS_RCU
Selected by CONFIG_RCU_TORTURE_TEST, so cannot disable.
CONFIG_RCU_TRACE
Implied by CONFIG_RCU_TRACE for Tree RCU.
These are controlled by CONFIG_PREEMPT.
boot parameters ignored: TBD
tools/testing/selftests/rcutorture/formal/srcu-cbmc/Makefile 0 → 100644
View file @ 31945aa9
all: srcu.c store_buffering
LINUX_SOURCE = ../../../../../..
modified_srcu_input = $(LINUX_SOURCE)/include/linux/srcu.h \
$(LINUX_SOURCE)/kernel/rcu/srcu.c
modified_srcu_output = include/linux/srcu.h srcu.c
include/linux/srcu.h: srcu.c
srcu.c: modify_srcu.awk Makefile $(modified_srcu_input)
awk -f modify_srcu.awk $(modified_srcu_input) $(modified_srcu_output)
store_buffering:
@cd tests/store_buffering; make
tools/testing/selftests/rcutorture/formal/srcu-cbmc/include/linux/types.h 0 → 100644
View file @ 31945aa9
/*
* This header has been modifies to remove definitions of types that
* are defined in standard userspace headers or are problematic for some
* other reason.
*/
#ifndef _LINUX_TYPES_H
#define _LINUX_TYPES_H
#define __EXPORTED_HEADERS__
#include <uapi/linux/types.h>
#ifndef __ASSEMBLY__
#define DECLARE_BITMAP(name, bits) \
unsigned long name[BITS_TO_LONGS(bits)]
typedef __u32 __kernel_dev_t;
/* bsd */
typedef unsigned char u_char;
typedef unsigned short u_short;
typedef unsigned int u_int;
typedef unsigned long u_long;
/* sysv */
typedef unsigned char unchar;
typedef unsigned short ushort;
typedef unsigned int uint;
typedef unsigned long ulong;
#ifndef __BIT_TYPES_DEFINED__
#define __BIT_TYPES_DEFINED__
typedef __u8 u_int8_t;
typedef __s8 int8_t;
typedef __u16 u_int16_t;
typedef __s16 int16_t;
typedef __u32 u_int32_t;
typedef __s32 int32_t;
#endif /* !(__BIT_TYPES_DEFINED__) */
typedef __u8 uint8_t;
typedef __u16 uint16_t;
typedef __u32 uint32_t;
/* this is a special 64bit data type that is 8-byte aligned */
#define aligned_u64 __u64 __attribute__((aligned(8)))
#define aligned_be64 __be64 __attribute__((aligned(8)))
#define aligned_le64 __le64 __attribute__((aligned(8)))
/**
* The type used for indexing onto a disc or disc partition.
*
* Linux always considers sectors to be 512 bytes long independently
* of the devices real block size.
*
* blkcnt_t is the type of the inode's block count.
*/
#ifdef CONFIG_LBDAF
typedef u64 sector_t;
#else
typedef unsigned long sector_t;
#endif
/*
* The type of an index into the pagecache.
*/
#define pgoff_t unsigned long
/*
* A dma_addr_t can hold any valid DMA address, i.e., any address returned
* by the DMA API.
*
* If the DMA API only uses 32-bit addresses, dma_addr_t need only be 32
* bits wide. Bus addresses, e.g., PCI BARs, may be wider than 32 bits,
* but drivers do memory-mapped I/O to ioremapped kernel virtual addresses,
* so they don't care about the size of the actual bus addresses.
*/
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
typedef u64 dma_addr_t;
#else
typedef u32 dma_addr_t;
#endif
#ifdef CONFIG_PHYS_ADDR_T_64BIT
typedef u64 phys_addr_t;
#else
typedef u32 phys_addr_t;
#endif
typedef phys_addr_t resource_size_t;
/*
* This type is the placeholder for a hardware interrupt number. It has to be
* big enough to enclose whatever representation is used by a given platform.
*/
typedef unsigned long irq_hw_number_t;
typedef struct {
int counter;
} atomic_t;
#ifdef CONFIG_64BIT
typedef struct {
long counter;
} atomic64_t;
#endif
struct list_head {
struct list_head *next, *prev;
};
struct hlist_head {
struct hlist_node *first;
};
struct hlist_node {
struct hlist_node *next, **pprev;
};
/**
* struct callback_head - callback structure for use with RCU and task_work
* @next: next update requests in a list
* @func: actual update function to call after the grace period.
*
* The struct is aligned to size of pointer. On most architectures it happens
* naturally due ABI requirements, but some architectures (like CRIS) have
* weird ABI and we need to ask it explicitly.
*
* The alignment is required to guarantee that bits 0 and 1 of @next will be
* clear under normal conditions -- as long as we use call_rcu(),
* call_rcu_bh(), call_rcu_sched(), or call_srcu() to queue callback.
*
* This guarantee is important for few reasons:
* - future call_rcu_lazy() will make use of lower bits in the pointer;
* - the structure shares storage spacer in struct page with @compound_head,
* which encode PageTail() in bit 0. The guarantee is needed to avoid
* false-positive PageTail().
*/
struct callback_head {
struct callback_head *next;
void (*func)(struct callback_head *head);
} __attribute__((aligned(sizeof(void *))));
#define rcu_head callback_head
typedef void (*rcu_callback_t)(struct rcu_head *head);
typedef void (*call_rcu_func_t)(struct rcu_head *head, rcu_callback_t func);
/* clocksource cycle base type */
typedef u64 cycle_t;
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_TYPES_H */
tools/testing/selftests/rcutorture/formal/srcu-cbmc/modify_srcu.awk 0 → 100755
View file @ 31945aa9
#!/bin/awk -f
# Modify SRCU for formal verification. The first argument should be srcu.h and
# the second should be srcu.c. Outputs modified srcu.h and srcu.c into the
# current directory.
BEGIN {
if (ARGC != 5) {
print "Usange: input.h input.c output.h output.c" > "/dev/stderr";
exit 1;
}
h_output = ARGV[3];
c_output = ARGV[4];
ARGC = 3;
# Tokenize using FS and not RS as FS supports regular expressions. Each
# record is one line of source, except that backslashed lines are
# combined. Comments are treated as field separators, as are quotes.
quote_regexp="\"([^\\\\\"]|\\\\.)*\"";
comment_regexp="\\/\\*([^*]|\\*+[^*/])*\\*\\/|\\/\\/.*(\n|$)";
FS="([ \\\\\t\n\v\f;,.=(){}+*/<>&|^-]|\\[|\\]|" comment_regexp "|" quote_regexp ")+";
inside_srcu_struct = 0;
inside_srcu_init_def = 0;
srcu_init_param_name = "";
in_macro = 0;
brace_nesting = 0;
paren_nesting = 0;
# Allow the manipulation of the last field separator after has been
# seen.
last_fs = "";
# Whether the last field separator was intended to be output.
last_fs_print = 0;
# rcu_batches stores the initialization for each instance of struct
# rcu_batch
in_comment = 0;
outputfile = "";
}
{
prev_outputfile = outputfile;
if (FILENAME ~ /\.h$/) {
outputfile = h_output;
if (FNR != NR) {
print "Incorrect file order" > "/dev/stderr";
exit 1;
}
}
else
outputfile = c_output;
if (prev_outputfile && outputfile != prev_outputfile) {
new_outputfile = outputfile;
outputfile = prev_outputfile;
update_fieldsep("", 0);
outputfile = new_outputfile;
}
}
# Combine the next line into $0.
function combine_line() {
ret = getline next_line;
if (ret == 0) {
# Don't allow two consecutive getlines at the end of the file
if (eof_found) {
print "Error: expected more input." > "/dev/stderr";
exit 1;
} else {
eof_found = 1;
}
} else if (ret == -1) {
print "Error reading next line of file" FILENAME > "/dev/stderr";
exit 1;
}
$0 = $0 "\n" next_line;
}
# Combine backslashed lines and multiline comments.
function combine_backslashes() {
while (/\\$|\/\*([^*]|\*+[^*\/])*\**$/) {
combine_line();
}
}
function read_line() {
combine_line();
combine_backslashes();
}
# Print out field separators and update variables that depend on them. Only
# print if p is true. Call with sep="" and p=0 to print out the last field
# separator.
function update_fieldsep(sep, p) {
# Count braces
sep_tmp = sep;
gsub(quote_regexp "|" comment_regexp, "", sep_tmp);
while (1)
{
if (sub("[^{}()]*\\{", "", sep_tmp)) {
brace_nesting++;
continue;
}
if (sub("[^{}()]*\\}", "", sep_tmp)) {
brace_nesting--;
if (brace_nesting < 0) {
print "Unbalanced braces!" > "/dev/stderr";
exit 1;
}
continue;
}
if (sub("[^{}()]*\\(", "", sep_tmp)) {
paren_nesting++;
continue;
}
if (sub("[^{}()]*\\)", "", sep_tmp)) {
paren_nesting--;
if (paren_nesting < 0) {
print "Unbalanced parenthesis!" > "/dev/stderr";
exit 1;
}
continue;
}
break;
}
if (last_fs_print)
printf("%s", last_fs) > outputfile;
last_fs = sep;
last_fs_print = p;
}
# Shifts the fields down by n positions. Calls next if there are no more. If p
# is true then print out field separators.
function shift_fields(n, p) {
do {
if (match($0, FS) > 0) {
update_fieldsep(substr($0, RSTART, RLENGTH), p);
if (RSTART + RLENGTH <= length())
$0 = substr($0, RSTART + RLENGTH);
else
$0 = "";
} else {
update_fieldsep("", 0);
print "" > outputfile;
next;
}
} while (--n > 0);
}
# Shifts and prints the first n fields.
function print_fields(n) {
do {
update_fieldsep("", 0);
printf("%s", $1) > outputfile;
shift_fields(1, 1);
} while (--n > 0);
}
{
combine_backslashes();
}
# Print leading FS
{
if (match($0, "^(" FS ")+") > 0) {
update_fieldsep(substr($0, RSTART, RLENGTH), 1);
if (RSTART + RLENGTH <= length())
$0 = substr($0, RSTART + RLENGTH);
else
$0 = "";
}
}
# Parse the line.
{
while (NF > 0) {
if ($1 == "struct" && NF < 3) {
read_line();
continue;
}
if (FILENAME ~ /\.h$/ && !inside_srcu_struct &&
brace_nesting == 0 && paren_nesting == 0 &&
$1 == "struct" && $2 == "srcu_struct" &&
$0 ~ "^struct(" FS ")+srcu_struct(" FS ")+\\{") {
inside_srcu_struct = 1;
print_fields(2);
continue;
}
if (inside_srcu_struct && brace_nesting == 0 &&
paren_nesting == 0) {
inside_srcu_struct = 0;
update_fieldsep("", 0);
for (name in rcu_batches)
print "extern struct rcu_batch " name ";" > outputfile;
}
if (inside_srcu_struct && $1 == "struct" && $2 == "rcu_batch") {
# Move rcu_batches outside of the struct.
rcu_batches[$3] = "";
shift_fields(3, 1);
sub(/;[[:space:]]*$/, "", last_fs);
continue;
}
if (FILENAME ~ /\.h$/ && !inside_srcu_init_def &&
$1 == "#define" && $2 == "__SRCU_STRUCT_INIT") {
inside_srcu_init_def = 1;
srcu_init_param_name = $3;
in_macro = 1;
print_fields(3);
continue;
}
if (inside_srcu_init_def && brace_nesting == 0 &&
paren_nesting == 0) {
inside_srcu_init_def = 0;
in_macro = 0;
continue;
}
if (inside_srcu_init_def && brace_nesting == 1 &&
paren_nesting == 0 && last_fs ~ /\.[[:space:]]*$/ &&
$1 ~ /^[[:alnum:]_]+$/) {
name = $1;
if (name in rcu_batches) {
# Remove the dot.
sub(/\.[[:space:]]*$/, "", last_fs);
old_record = $0;
do
shift_fields(1, 0);
while (last_fs !~ /,/ || paren_nesting > 0);
end_loc = length(old_record) - length($0);
end_loc += index(last_fs, ",") - length(last_fs);
last_fs = substr(last_fs, index(last_fs, ",") + 1);
last_fs_print = 1;
match(old_record, "^"name"("FS")+=");
start_loc = RSTART + RLENGTH;
len = end_loc - start_loc;
initializer = substr(old_record, start_loc, len);
gsub(srcu_init_param_name "\\.", "", initializer);
rcu_batches[name] = initializer;
continue;
}
}
# Don't include a nonexistent file
if (!in_macro && $1 == "#include" && /^#include[[:space:]]+"rcu\.h"/) {
update_fieldsep("", 0);
next;
}
# Ignore most preprocessor stuff.
if (!in_macro && $1 ~ /#/) {
break;
}
if (brace_nesting > 0 && $1 ~ "^[[:alnum:]_]+$" && NF < 2) {
read_line();
continue;
}
if (brace_nesting > 0 &&
$0 ~ "^[[:alnum:]_]+[[:space:]]*(\\.|->)[[:space:]]*[[:alnum:]_]+" &&
$2 in rcu_batches) {
# Make uses of rcu_batches global. Somewhat unreliable.
shift_fields(1, 0);
print_fields(1);
continue;
}
if ($1 == "static" && NF < 3) {
read_line();
continue;
}
if ($1 == "static" && ($2 == "bool" && $3 == "try_check_zero" ||
$2 == "void" && $3 == "srcu_flip")) {
shift_fields(1, 1);
print_fields(2);
continue;
}
# Distinguish between read-side and write-side memory barriers.
if ($1 == "smp_mb" && NF < 2) {
read_line();
continue;
}
if (match($0, /^smp_mb[[:space:]();\/*]*[[:alnum:]]/)) {
barrier_letter = substr($0, RLENGTH, 1);
if (barrier_letter ~ /A|D/)
new_barrier_name = "sync_smp_mb";
else if (barrier_letter ~ /B|C/)
new_barrier_name = "rs_smp_mb";
else {
print "Unrecognized memory barrier." > "/dev/null";
exit 1;
}
shift_fields(1, 1);
printf("%s", new_barrier_name) > outputfile;
continue;
}
# Skip definition of rcu_synchronize, since it is already
# defined in misc.h. Only present in old versions of srcu.
if (brace_nesting == 0 && paren_nesting == 0 &&
$1 == "struct" && $2 == "rcu_synchronize" &&
$0 ~ "^struct(" FS ")+rcu_synchronize(" FS ")+\\{") {
shift_fields(2, 0);
while (brace_nesting) {
if (NF < 2)
read_line();
shift_fields(1, 0);
}
}
# Skip definition of wakeme_after_rcu for the same reason
if (brace_nesting == 0 && $1 == "static" && $2 == "void" &&
$3 == "wakeme_after_rcu") {
while (NF < 5)
read_line();
shift_fields(3, 0);
do {
while (NF < 3)
read_line();
shift_fields(1, 0);
} while (paren_nesting || brace_nesting);
}
if ($1 ~ /^(unsigned|long)$/ && NF < 3) {
read_line();
continue;
}
# Give srcu_batches_completed the correct type for old SRCU.
if (brace_nesting == 0 && $1 == "long" &&
$2 == "srcu_batches_completed") {
update_fieldsep("", 0);
printf("unsigned ") > outputfile;
print_fields(2);
continue;
}
if (brace_nesting == 0 && $1 == "unsigned" && $2 == "long" &&
$3 == "srcu_batches_completed") {
print_fields(3);
continue;
}
# Just print out the input code by default.
print_fields(1);
}
update_fieldsep("", 0);
print > outputfile;
next;
}
END {
update_fieldsep("", 0);
if (brace_nesting != 0) {
print "Unbalanced braces!" > "/dev/stderr";
exit 1;
}
# Define the rcu_batches
for (name in rcu_batches)
print "struct rcu_batch " name " = " rcu_batches[name] ";" > c_output;
}
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/assume.h 0 → 100644
View file @ 31945aa9
#ifndef ASSUME_H
#define ASSUME_H
/* Provide an assumption macro that can be disabled for gcc. */
#ifdef RUN
#define assume(x) \
do { \
/* Evaluate x to suppress warnings. */ \
(void) (x); \
} while (0)
#else
#define assume(x) __CPROVER_assume(x)
#endif
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h 0 → 100644
View file @ 31945aa9
#ifndef BARRIERS_H
#define BARRIERS_H
#define barrier() __asm__ __volatile__("" : : : "memory")
#ifdef RUN
#define smp_mb() __sync_synchronize()
#define smp_mb__after_unlock_lock() __sync_synchronize()
#else
/*
* Copied from CBMC's implementation of __sync_synchronize(), which
* seems to be disabled by default.
*/
#define smp_mb() __CPROVER_fence("WWfence", "RRfence", "RWfence", "WRfence", \
"WWcumul", "RRcumul", "RWcumul", "WRcumul")
#define smp_mb__after_unlock_lock() __CPROVER_fence("WWfence", "RRfence", "RWfence", "WRfence", \
"WWcumul", "RRcumul", "RWcumul", "WRcumul")
#endif
/*
* Allow memory barriers to be disabled in either the read or write side
* of SRCU individually.
*/
#ifndef NO_SYNC_SMP_MB
#define sync_smp_mb() smp_mb()
#else
#define sync_smp_mb() do {} while (0)
#endif
#ifndef NO_READ_SIDE_SMP_MB
#define rs_smp_mb() smp_mb()
#else
#define rs_smp_mb() do {} while (0)
#endif
#define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x))
#define READ_ONCE(x) ACCESS_ONCE(x)
#define WRITE_ONCE(x, val) (ACCESS_ONCE(x) = (val))
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/bug_on.h 0 → 100644
View file @ 31945aa9
#ifndef BUG_ON_H
#define BUG_ON_H
#include <assert.h>
#define BUG() assert(0)
#define BUG_ON(x) assert(!(x))
/* Does it make sense to treat warnings as errors? */
#define WARN() BUG()
#define WARN_ON(x) (BUG_ON(x), false)
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/combined_source.c 0 → 100644
View file @ 31945aa9
#include <config.h>
/* Include all source files. */
#include "include_srcu.c"
#include "preempt.c"
#include "misc.c"
/* Used by test.c files */
#include <pthread.h>
#include <stdlib.h>
#include <linux/srcu.h>
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/config.h 0 → 100644
View file @ 31945aa9
/* "Cheater" definitions based on restricted Kconfig choices. */
#undef CONFIG_TINY_RCU
#undef __CHECKER__
#undef CONFIG_DEBUG_LOCK_ALLOC
#undef CONFIG_DEBUG_OBJECTS_RCU_HEAD
#undef CONFIG_HOTPLUG_CPU
#undef CONFIG_MODULES
#undef CONFIG_NO_HZ_FULL_SYSIDLE
#undef CONFIG_PREEMPT_COUNT
#undef CONFIG_PREEMPT_RCU
#undef CONFIG_PROVE_RCU
#undef CONFIG_RCU_NOCB_CPU
#undef CONFIG_RCU_NOCB_CPU_ALL
#undef CONFIG_RCU_STALL_COMMON
#undef CONFIG_RCU_TRACE
#undef CONFIG_RCU_USER_QS
#undef CONFIG_TASKS_RCU
#define CONFIG_TREE_RCU
#define CONFIG_GENERIC_ATOMIC64
#if NR_CPUS > 1
#define CONFIG_SMP
#else
#undef CONFIG_SMP
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/include_srcu.c 0 → 100644
View file @ 31945aa9
#include <config.h>
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <pthread.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include "int_typedefs.h"
#include "barriers.h"
#include "bug_on.h"
#include "locks.h"
#include "misc.h"
#include "preempt.h"
#include "percpu.h"
#include "workqueues.h"
#ifdef USE_SIMPLE_SYNC_SRCU
#define synchronize_srcu(sp) synchronize_srcu_original(sp)
#endif
#include <srcu.c>
#ifdef USE_SIMPLE_SYNC_SRCU
#undef synchronize_srcu
#include "simple_sync_srcu.c"
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/int_typedefs.h 0 → 100644
View file @ 31945aa9
#ifndef INT_TYPEDEFS_H
#define INT_TYPEDEFS_H
#include <inttypes.h>
typedef int8_t s8;
typedef uint8_t u8;
typedef int16_t s16;
typedef uint16_t u16;
typedef int32_t s32;
typedef uint32_t u32;
typedef int64_t s64;
typedef uint64_t u64;
typedef int8_t __s8;
typedef uint8_t __u8;
typedef int16_t __s16;
typedef uint16_t __u16;
typedef int32_t __s32;
typedef uint32_t __u32;
typedef int64_t __s64;
typedef uint64_t __u64;
#define S8_C(x) INT8_C(x)
#define U8_C(x) UINT8_C(x)
#define S16_C(x) INT16_C(x)
#define U16_C(x) UINT16_C(x)
#define S32_C(x) INT32_C(x)
#define U32_C(x) UINT32_C(x)
#define S64_C(x) INT64_C(x)
#define U64_C(x) UINT64_C(x)
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/locks.h 0 → 100644
View file @ 31945aa9
#ifndef LOCKS_H
#define LOCKS_H
#include <limits.h>
#include <pthread.h>
#include <stdbool.h>
#include "assume.h"
#include "bug_on.h"
#include "preempt.h"
int nondet_int(void);
#define __acquire(x)
#define __acquires(x)
#define __release(x)
#define __releases(x)
/* Only use one lock mechanism. Select which one. */
#ifdef PTHREAD_LOCK
struct lock_impl {
pthread_mutex_t mutex;
};
static inline void lock_impl_lock(struct lock_impl *lock)
{
BUG_ON(pthread_mutex_lock(&lock->mutex));
}
static inline void lock_impl_unlock(struct lock_impl *lock)
{
BUG_ON(pthread_mutex_unlock(&lock->mutex));
}
static inline bool lock_impl_trylock(struct lock_impl *lock)
{
int err = pthread_mutex_trylock(&lock->mutex);
if (!err)
return true;
else if (err == EBUSY)
return false;
BUG();
}
static inline void lock_impl_init(struct lock_impl *lock)
{
pthread_mutex_init(&lock->mutex, NULL);
}
#define LOCK_IMPL_INITIALIZER {.mutex = PTHREAD_MUTEX_INITIALIZER}
#else /* !defined(PTHREAD_LOCK) */
/* Spinlock that assumes that it always gets the lock immediately. */
struct lock_impl {
bool locked;
};
static inline bool lock_impl_trylock(struct lock_impl *lock)
{
#ifdef RUN
/* TODO: Should this be a test and set? */
return __sync_bool_compare_and_swap(&lock->locked, false, true);
#else
__CPROVER_atomic_begin();
bool old_locked = lock->locked;
lock->locked = true;
__CPROVER_atomic_end();
/* Minimal barrier to prevent accesses leaking out of lock. */
__CPROVER_fence("RRfence", "RWfence");
return !old_locked;
#endif
}
static inline void lock_impl_lock(struct lock_impl *lock)
{
/*
* CBMC doesn't support busy waiting, so just assume that the
* lock is available.
*/
assume(lock_impl_trylock(lock));
/*
* If the lock was already held by this thread then the assumption
* is unsatisfiable (deadlock).
*/
}
static inline void lock_impl_unlock(struct lock_impl *lock)
{
#ifdef RUN
BUG_ON(!__sync_bool_compare_and_swap(&lock->locked, true, false));
#else
/* Minimal barrier to prevent accesses leaking out of lock. */
__CPROVER_fence("RWfence", "WWfence");
__CPROVER_atomic_begin();
bool old_locked = lock->locked;
lock->locked = false;
__CPROVER_atomic_end();
BUG_ON(!old_locked);
#endif
}
static inline void lock_impl_init(struct lock_impl *lock)
{
lock->locked = false;
}
#define LOCK_IMPL_INITIALIZER {.locked = false}
#endif /* !defined(PTHREAD_LOCK) */
/*
* Implement spinlocks using the lock mechanism. Wrap the lock to prevent mixing
* locks of different types.
*/
typedef struct {
struct lock_impl internal_lock;
} spinlock_t;
#define SPIN_LOCK_UNLOCKED {.internal_lock = LOCK_IMPL_INITIALIZER}
#define __SPIN_LOCK_UNLOCKED(x) SPIN_LOCK_UNLOCKED
#define DEFINE_SPINLOCK(x) spinlock_t x = SPIN_LOCK_UNLOCKED
static inline void spin_lock_init(spinlock_t *lock)
{
lock_impl_init(&lock->internal_lock);
}
static inline void spin_lock(spinlock_t *lock)
{
/*
* Spin locks also need to be removed in order to eliminate all
* memory barriers. They are only used by the write side anyway.
*/
#ifndef NO_SYNC_SMP_MB
preempt_disable();
lock_impl_lock(&lock->internal_lock);
#endif
}
static inline void spin_unlock(spinlock_t *lock)
{
#ifndef NO_SYNC_SMP_MB
lock_impl_unlock(&lock->internal_lock);
preempt_enable();
#endif
}
/* Don't bother with interrupts */
#define spin_lock_irq(lock) spin_lock(lock)
#define spin_unlock_irq(lock) spin_unlock(lock)
#define spin_lock_irqsave(lock, flags) spin_lock(lock)
#define spin_unlock_irqrestore(lock, flags) spin_unlock(lock)
/*
* This is supposed to return an int, but I think that a bool should work as
* well.
*/
static inline bool spin_trylock(spinlock_t *lock)
{
#ifndef NO_SYNC_SMP_MB
preempt_disable();
return lock_impl_trylock(&lock->internal_lock);
#else
return true;
#endif
}
struct completion {
/* Hopefuly this won't overflow. */
unsigned int count;
};
#define COMPLETION_INITIALIZER(x) {.count = 0}
#define DECLARE_COMPLETION(x) struct completion x = COMPLETION_INITIALIZER(x)
#define DECLARE_COMPLETION_ONSTACK(x) DECLARE_COMPLETION(x)
static inline void init_completion(struct completion *c)
{
c->count = 0;
}
static inline void wait_for_completion(struct completion *c)
{
unsigned int prev_count = __sync_fetch_and_sub(&c->count, 1);
assume(prev_count);
}
static inline void complete(struct completion *c)
{
unsigned int prev_count = __sync_fetch_and_add(&c->count, 1);
BUG_ON(prev_count == UINT_MAX);
}
/* This function probably isn't very useful for CBMC. */
static inline bool try_wait_for_completion(struct completion *c)
{
BUG();
}
static inline bool completion_done(struct completion *c)
{
return c->count;
}
/* TODO: Implement complete_all */
static inline void complete_all(struct completion *c)
{
BUG();
}
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.c 0 → 100644
View file @ 31945aa9
#include <config.h>
#include "misc.h"
#include "bug_on.h"
struct rcu_head;
void wakeme_after_rcu(struct rcu_head *head)
{
BUG();
}
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/misc.h 0 → 100644
View file @ 31945aa9
#ifndef MISC_H
#define MISC_H
#include "assume.h"
#include "int_typedefs.h"
#include "locks.h"
#include <linux/types.h>
/* Probably won't need to deal with bottom halves. */
static inline void local_bh_disable(void) {}
static inline void local_bh_enable(void) {}
#define MODULE_ALIAS(X)
#define module_param(...)
#define EXPORT_SYMBOL_GPL(x)
#define container_of(ptr, type, member) ({ \
const typeof(((type *)0)->member) *__mptr = (ptr); \
(type *)((char *)__mptr - offsetof(type, member)); \
})
#ifndef USE_SIMPLE_SYNC_SRCU
/* Abuse udelay to make sure that busy loops terminate. */
#define udelay(x) assume(0)
#else
/* The simple custom synchronize_srcu is ok with try_check_zero failing. */
#define udelay(x) do { } while (0)
#endif
#define trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
do { } while (0)
#define notrace
/* Avoid including rcupdate.h */
struct rcu_synchronize {
struct rcu_head head;
struct completion completion;
};
void wakeme_after_rcu(struct rcu_head *head);
#define rcu_lock_acquire(a) do { } while (0)
#define rcu_lock_release(a) do { } while (0)
#define rcu_lockdep_assert(c, s) do { } while (0)
#define RCU_LOCKDEP_WARN(c, s) do { } while (0)
/* Let CBMC non-deterministically choose switch between normal and expedited. */
bool rcu_gp_is_normal(void);
bool rcu_gp_is_expedited(void);
/* Do the same for old versions of rcu. */
#define rcu_expedited (rcu_gp_is_expedited())
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/percpu.h 0 → 100644
View file @ 31945aa9
#ifndef PERCPU_H
#define PERCPU_H
#include <stddef.h>
#include "bug_on.h"
#include "preempt.h"
#define __percpu
/* Maximum size of any percpu data. */
#define PERCPU_OFFSET (4 * sizeof(long))
/* Ignore alignment, as CBMC doesn't care about false sharing. */
#define alloc_percpu(type) __alloc_percpu(sizeof(type), 1)
static inline void *__alloc_percpu(size_t size, size_t align)
{
BUG();
return NULL;
}
static inline void free_percpu(void *ptr)
{
BUG();
}
#define per_cpu_ptr(ptr, cpu) \
((typeof(ptr)) ((char *) (ptr) + PERCPU_OFFSET * cpu))
#define __this_cpu_inc(pcp) __this_cpu_add(pcp, 1)
#define __this_cpu_dec(pcp) __this_cpu_sub(pcp, 1)
#define __this_cpu_sub(pcp, n) __this_cpu_add(pcp, -(typeof(pcp)) (n))
#define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
#define this_cpu_dec(pcp) this_cpu_sub(pcp, 1)
#define this_cpu_sub(pcp, n) this_cpu_add(pcp, -(typeof(pcp)) (n))
/* Make CBMC use atomics to work around bug. */
#ifdef RUN
#define THIS_CPU_ADD_HELPER(ptr, x) (*(ptr) += (x))
#else
/*
* Split the atomic into a read and a write so that it has the least
* possible ordering.
*/
#define THIS_CPU_ADD_HELPER(ptr, x) \
do { \
typeof(ptr) this_cpu_add_helper_ptr = (ptr); \
typeof(ptr) this_cpu_add_helper_x = (x); \
typeof(*ptr) this_cpu_add_helper_temp; \
__CPROVER_atomic_begin(); \
this_cpu_add_helper_temp = *(this_cpu_add_helper_ptr); \
__CPROVER_atomic_end(); \
this_cpu_add_helper_temp += this_cpu_add_helper_x; \
__CPROVER_atomic_begin(); \
*(this_cpu_add_helper_ptr) = this_cpu_add_helper_temp; \
__CPROVER_atomic_end(); \
} while (0)
#endif
/*
* For some reason CBMC needs an atomic operation even though this is percpu
* data.
*/
#define __this_cpu_add(pcp, n) \
do { \
BUG_ON(preemptible()); \
THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), thread_cpu_id), \
(typeof(pcp)) (n)); \
} while (0)
#define this_cpu_add(pcp, n) \
do { \
int this_cpu_add_impl_cpu = get_cpu(); \
THIS_CPU_ADD_HELPER(per_cpu_ptr(&(pcp), this_cpu_add_impl_cpu), \
(typeof(pcp)) (n)); \
put_cpu(); \
} while (0)
/*
* This will cause a compiler warning because of the cast from char[][] to
* type*. This will cause a compile time error if type is too big.
*/
#define DEFINE_PER_CPU(type, name) \
char name[NR_CPUS][PERCPU_OFFSET]; \
typedef char percpu_too_big_##name \
[sizeof(type) > PERCPU_OFFSET ? -1 : 1]
#define for_each_possible_cpu(cpu) \
for ((cpu) = 0; (cpu) < NR_CPUS; ++(cpu))
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.c 0 → 100644
View file @ 31945aa9
#include <config.h>
#include "preempt.h"
#include "assume.h"
#include "locks.h"
/* Support NR_CPUS of at most 64 */
#define CPU_PREEMPTION_LOCKS_INIT0 LOCK_IMPL_INITIALIZER
#define CPU_PREEMPTION_LOCKS_INIT1 \
CPU_PREEMPTION_LOCKS_INIT0, CPU_PREEMPTION_LOCKS_INIT0
#define CPU_PREEMPTION_LOCKS_INIT2 \
CPU_PREEMPTION_LOCKS_INIT1, CPU_PREEMPTION_LOCKS_INIT1
#define CPU_PREEMPTION_LOCKS_INIT3 \
CPU_PREEMPTION_LOCKS_INIT2, CPU_PREEMPTION_LOCKS_INIT2
#define CPU_PREEMPTION_LOCKS_INIT4 \
CPU_PREEMPTION_LOCKS_INIT3, CPU_PREEMPTION_LOCKS_INIT3
#define CPU_PREEMPTION_LOCKS_INIT5 \
CPU_PREEMPTION_LOCKS_INIT4, CPU_PREEMPTION_LOCKS_INIT4
/*
* Simulate disabling preemption by locking a particular cpu. NR_CPUS
* should be the actual number of cpus, not just the maximum.
*/
struct lock_impl cpu_preemption_locks[NR_CPUS] = {
CPU_PREEMPTION_LOCKS_INIT0
#if (NR_CPUS - 1) & 1
, CPU_PREEMPTION_LOCKS_INIT0
#endif
#if (NR_CPUS - 1) & 2
, CPU_PREEMPTION_LOCKS_INIT1
#endif
#if (NR_CPUS - 1) & 4
, CPU_PREEMPTION_LOCKS_INIT2
#endif
#if (NR_CPUS - 1) & 8
, CPU_PREEMPTION_LOCKS_INIT3
#endif
#if (NR_CPUS - 1) & 16
, CPU_PREEMPTION_LOCKS_INIT4
#endif
#if (NR_CPUS - 1) & 32
, CPU_PREEMPTION_LOCKS_INIT5
#endif
};
#undef CPU_PREEMPTION_LOCKS_INIT0
#undef CPU_PREEMPTION_LOCKS_INIT1
#undef CPU_PREEMPTION_LOCKS_INIT2
#undef CPU_PREEMPTION_LOCKS_INIT3
#undef CPU_PREEMPTION_LOCKS_INIT4
#undef CPU_PREEMPTION_LOCKS_INIT5
__thread int thread_cpu_id;
__thread int preempt_disable_count;
void preempt_disable(void)
{
BUG_ON(preempt_disable_count < 0 || preempt_disable_count == INT_MAX);
if (preempt_disable_count++)
return;
thread_cpu_id = nondet_int();
assume(thread_cpu_id >= 0);
assume(thread_cpu_id < NR_CPUS);
lock_impl_lock(&cpu_preemption_locks[thread_cpu_id]);
}
void preempt_enable(void)
{
BUG_ON(preempt_disable_count < 1);
if (--preempt_disable_count)
return;
lock_impl_unlock(&cpu_preemption_locks[thread_cpu_id]);
}
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/preempt.h 0 → 100644
View file @ 31945aa9
#ifndef PREEMPT_H
#define PREEMPT_H
#include <stdbool.h>
#include "bug_on.h"
/* This flag contains garbage if preempt_disable_count is 0. */
extern __thread int thread_cpu_id;
/* Support recursive preemption disabling. */
extern __thread int preempt_disable_count;
void preempt_disable(void);
void preempt_enable(void);
static inline void preempt_disable_notrace(void)
{
preempt_disable();
}
static inline void preempt_enable_no_resched(void)
{
preempt_enable();
}
static inline void preempt_enable_notrace(void)
{
preempt_enable();
}
static inline int preempt_count(void)
{
return preempt_disable_count;
}
static inline bool preemptible(void)
{
return !preempt_count();
}
static inline int get_cpu(void)
{
preempt_disable();
return thread_cpu_id;
}
static inline void put_cpu(void)
{
preempt_enable();
}
static inline void might_sleep(void)
{
BUG_ON(preempt_disable_count);
}
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/simple_sync_srcu.c 0 → 100644
View file @ 31945aa9
#include <config.h>
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <pthread.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include "int_typedefs.h"
#include "barriers.h"
#include "bug_on.h"
#include "locks.h"
#include "misc.h"
#include "preempt.h"
#include "percpu.h"
#include "workqueues.h"
#include <linux/srcu.h>
/* Functions needed from modify_srcu.c */
bool try_check_zero(struct srcu_struct *sp, int idx, int trycount);
void srcu_flip(struct srcu_struct *sp);
/* Simpler implementation of synchronize_srcu that ignores batching. */
void synchronize_srcu(struct srcu_struct *sp)
{
int idx;
/*
* This code assumes that try_check_zero will succeed anyway,
* so there is no point in multiple tries.
*/
const int trycount = 1;
might_sleep();
/* Ignore the lock, as multiple writers aren't working yet anyway. */
idx = 1 ^ (sp->completed & 1);
/* For comments see srcu_advance_batches. */
assume(try_check_zero(sp, idx, trycount));
srcu_flip(sp);
assume(try_check_zero(sp, idx^1, trycount));
}
tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/workqueues.h 0 → 100644
View file @ 31945aa9
#ifndef WORKQUEUES_H
#define WORKQUEUES_H
#include <stdbool.h>
#include "barriers.h"
#include "bug_on.h"
#include "int_typedefs.h"
#include <linux/types.h>
/* Stub workqueue implementation. */
struct work_struct;
typedef void (*work_func_t)(struct work_struct *work);
void delayed_work_timer_fn(unsigned long __data);
struct work_struct {
/* atomic_long_t data; */
unsigned long data;
struct list_head entry;
work_func_t func;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
};
struct timer_list {
struct hlist_node entry;
unsigned long expires;
void (*function)(unsigned long);
unsigned long data;
u32 flags;
int slack;
};
struct delayed_work {
struct work_struct work;
struct timer_list timer;
/* target workqueue and CPU ->timer uses to queue ->work */
struct workqueue_struct *wq;
int cpu;
};
static inline bool schedule_work(struct work_struct *work)
{
BUG();
return true;
}
static inline bool schedule_work_on(int cpu, struct work_struct *work)
{
BUG();
return true;
}
static inline bool queue_work(struct workqueue_struct *wq,
struct work_struct *work)
{
BUG();
return true;
}
static inline bool queue_delayed_work(struct workqueue_struct *wq,
struct delayed_work *dwork,
unsigned long delay)
{
BUG();
return true;
}
#define INIT_WORK(w, f) \
do { \
(w)->data = 0; \
(w)->func = (f); \
} while (0)
#define INIT_DELAYED_WORK(w, f) INIT_WORK(&(w)->work, (f))
#define __WORK_INITIALIZER(n, f) { \
.data = 0, \
.entry = { &(n).entry, &(n).entry }, \
.func = f \
}
/* Don't bother initializing timer. */
#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
.work = __WORK_INITIALIZER((n).work, (f)), \
}
#define DECLARE_WORK(n, f) \
struct workqueue_struct n = __WORK_INITIALIZER
#define DECLARE_DELAYED_WORK(n, f) \
struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
#define system_power_efficient_wq ((struct workqueue_struct *) NULL)
#endif
tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/Makefile 0 → 100644
View file @ 31945aa9
CBMC_FLAGS = -I../.. -I../../src -I../../include -I../../empty_includes -32 -pointer-check -mm pso
all:
for i in ./*.pass; do \
echo $$i ; \
CBMC_FLAGS="$(CBMC_FLAGS)" sh ../test_script.sh --should-pass $$i > $$i.out 2>&1 ; \
done
for i in ./*.fail; do \
echo $$i ; \
CBMC_FLAGS="$(CBMC_FLAGS)" sh ../test_script.sh --should-fail $$i > $$i.out 2>&1 ; \
done
tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/store_buffering/test.c 0 → 100644
View file @ 31945aa9
#include <src/combined_source.c>
int x;
int y;
int __unbuffered_tpr_x;
int __unbuffered_tpr_y;
DEFINE_SRCU(ss);
void rcu_reader(void)
{
int idx;
#ifndef FORCE_FAILURE_3
idx = srcu_read_lock(&ss);
#endif
might_sleep();
__unbuffered_tpr_y = READ_ONCE(y);
#ifdef FORCE_FAILURE
srcu_read_unlock(&ss, idx);
idx = srcu_read_lock(&ss);
#endif
WRITE_ONCE(x, 1);
#ifndef FORCE_FAILURE_3
srcu_read_unlock(&ss, idx);
#endif
might_sleep();
}
void *thread_update(void *arg)
{
WRITE_ONCE(y, 1);
#ifndef FORCE_FAILURE_2
synchronize_srcu(&ss);
#endif
might_sleep();
__unbuffered_tpr_x = READ_ONCE(x);
return NULL;
}
void *thread_process_reader(void *arg)
{
rcu_reader();
return NULL;
}
int main(int argc, char *argv[])
{
pthread_t tu;
pthread_t tpr;
if (pthread_create(&tu, NULL, thread_update, NULL))
abort();
if (pthread_create(&tpr, NULL, thread_process_reader, NULL))
abort();
if (pthread_join(tu, NULL))
abort();
if (pthread_join(tpr, NULL))
abort();
assert(__unbuffered_tpr_y != 0 || __unbuffered_tpr_x != 0);
#ifdef ASSERT_END
assert(0);
#endif
return 0;
}
tools/testing/selftests/rcutorture/formal/srcu-cbmc/tests/test_script.sh 0 → 100755
View file @ 31945aa9
#!/bin/sh
# This script expects a mode (either --should-pass or --should-fail) followed by
# an input file. The script uses the following environment variables. The test C
# source file is expected to be named test.c in the directory containing the
# input file.
#
# CBMC: The command to run CBMC. Default: cbmc
# CBMC_FLAGS: Additional flags to pass to CBMC
# NR_CPUS: Number of cpus to run tests with. Default specified by the test
# SYNC_SRCU_MODE: Choose implementation of synchronize_srcu. Defaults to simple.
# kernel: Version included in the linux kernel source.
# simple: Use try_check_zero directly.
#
# The input file is a script that is sourced by this file. It can define any of
# the following variables to configure the test.
#
# test_cbmc_options: Extra options to pass to CBMC.
# min_cpus_fail: Minimum number of CPUs (NR_CPUS) for verification to fail.
# The test is expected to pass if it is run with fewer. (Only
# useful for .fail files)
# default_cpus: Quantity of CPUs to use for the test, if not specified on the
# command line. Default: Larger of 2 and MIN_CPUS_FAIL.
set -e
if test "$#" -ne 2; then
echo "Expected one option followed by an input file" 1>&2
exit 99
fi
if test "x$1" = "x--should-pass"; then
should_pass="yes"
elif test "x$1" = "x--should-fail"; then
should_pass="no"
else
echo "Unrecognized argument '$1'" 1>&2
# Exit code 99 indicates a hard error.
exit 99
fi
CBMC=${CBMC:-cbmc}
SYNC_SRCU_MODE=${SYNC_SRCU_MODE:-simple}
case ${SYNC_SRCU_MODE} in
kernel) sync_srcu_mode_flags="" ;;
simple) sync_srcu_mode_flags="-DUSE_SIMPLE_SYNC_SRCU" ;;
*)
echo "Unrecognized argument '${SYNC_SRCU_MODE}'" 1>&2
exit 99
;;
esac
min_cpus_fail=1
c_file=`dirname "$2"`/test.c
# Source the input file.
. $2
if test ${min_cpus_fail} -gt 2; then
default_default_cpus=${min_cpus_fail}
else
default_default_cpus=2
fi
default_cpus=${default_cpus:-${default_default_cpus}}
cpus=${NR_CPUS:-${default_cpus}}
# Check if there are two few cpus to make the test fail.
if test $cpus -lt ${min_cpus_fail:-0}; then
should_pass="yes"
fi
cbmc_opts="-DNR_CPUS=${cpus} ${sync_srcu_mode_flags} ${test_cbmc_options} ${CBMC_FLAGS}"
echo "Running CBMC: ${CBMC} ${cbmc_opts} ${c_file}"
if ${CBMC} ${cbmc_opts} "${c_file}"; then
# Verification successful. Make sure that it was supposed to verify.
test "x${should_pass}" = xyes
else
cbmc_exit_status=$?
# An exit status of 10 indicates a failed verification.
# (see cbmc_parse_optionst::do_bmc in the CBMC source code)
if test ${cbmc_exit_status} -eq 10 && test "x${should_pass}" = xno; then
:
else
echo "CBMC returned ${cbmc_exit_status} exit status" 1>&2
# Parse errors have exit status 6. Any other type of error
# should be considered a hard error.
if test ${cbmc_exit_status} -ne 6 && \
test ${cbmc_exit_status} -ne 10; then
exit 99
else
exit 1
fi
fi
fi
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7