diff options
48 files changed, 501 insertions, 349 deletions
diff --git a/Documentation/RCU/arrayRCU.txt b/Documentation/RCU/arrayRCU.txt index 453ebe6953ee..f05a9afb2c39 100644 --- a/Documentation/RCU/arrayRCU.txt +++ b/Documentation/RCU/arrayRCU.txt @@ -10,7 +10,19 @@ also be used to protect arrays. Three situations are as follows: 3. Resizeable Arrays -Each of these situations are discussed below. +Each of these three situations involves an RCU-protected pointer to an +array that is separately indexed. It might be tempting to consider use +of RCU to instead protect the index into an array, however, this use +case is -not- supported. The problem with RCU-protected indexes into +arrays is that compilers can play way too many optimization games with +integers, which means that the rules governing handling of these indexes +are far more trouble than they are worth. If RCU-protected indexes into +arrays prove to be particularly valuable (which they have not thus far), +explicit cooperation from the compiler will be required to permit them +to be safely used. + +That aside, each of the three RCU-protected pointer situations are +described in the following sections. Situation 1: Hash Tables @@ -36,9 +48,9 @@ Quick Quiz: Why is it so important that updates be rare when Situation 3: Resizeable Arrays Use of RCU for resizeable arrays is demonstrated by the grow_ary() -function used by the System V IPC code. The array is used to map from -semaphore, message-queue, and shared-memory IDs to the data structure -that represents the corresponding IPC construct. The grow_ary() +function formerly used by the System V IPC code. The array is used +to map from semaphore, message-queue, and shared-memory IDs to the data +structure that represents the corresponding IPC construct. The grow_ary() function does not acquire any locks; instead its caller must hold the ids->sem semaphore. diff --git a/Documentation/RCU/lockdep.txt b/Documentation/RCU/lockdep.txt index cd83d2348fef..da51d3068850 100644 --- a/Documentation/RCU/lockdep.txt +++ b/Documentation/RCU/lockdep.txt @@ -47,11 +47,6 @@ checking of rcu_dereference() primitives: Use explicit check expression "c" along with srcu_read_lock_held()(). This is useful in code that is invoked by both SRCU readers and updaters. - rcu_dereference_index_check(p, c): - Use explicit check expression "c", but the caller - must supply one of the rcu_read_lock_held() functions. - This is useful in code that uses RCU-protected arrays - that is invoked by both RCU readers and updaters. rcu_dereference_raw(p): Don't check. (Use sparingly, if at all.) rcu_dereference_protected(p, c): @@ -64,11 +59,6 @@ checking of rcu_dereference() primitives: but retain the compiler constraints that prevent duplicating or coalescsing. This is useful when when testing the value of the pointer itself, for example, against NULL. - rcu_access_index(idx): - Return the value of the index and omit all barriers, but - retain the compiler constraints that prevent duplicating - or coalescsing. This is useful when when testing the - value of the index itself, for example, against -1. The rcu_dereference_check() check expression can be any boolean expression, but would normally include a lockdep expression. However, diff --git a/Documentation/RCU/rcu_dereference.txt b/Documentation/RCU/rcu_dereference.txt index ceb05da5a5ac..1e6c0da994f5 100644 --- a/Documentation/RCU/rcu_dereference.txt +++ b/Documentation/RCU/rcu_dereference.txt @@ -25,17 +25,6 @@ o You must use one of the rcu_dereference() family of primitives for an example where the compiler can in fact deduce the exact value of the pointer, and thus cause misordering. -o Do not use single-element RCU-protected arrays. The compiler - is within its right to assume that the value of an index into - such an array must necessarily evaluate to zero. The compiler - could then substitute the constant zero for the computation, so - that the array index no longer depended on the value returned - by rcu_dereference(). If the array index no longer depends - on rcu_dereference(), then both the compiler and the CPU - are within their rights to order the array access before the - rcu_dereference(), which can cause the array access to return - garbage. - o Avoid cancellation when using the "+" and "-" infix arithmetic operators. For example, for a given variable "x", avoid "(x-x)". There are similar arithmetic pitfalls from other @@ -76,14 +65,15 @@ o Do not use the results from the boolean "&&" and "||" when dereferencing. For example, the following (rather improbable) code is buggy: - int a[2]; - int index; - int force_zero_index = 1; + int *p; + int *q; ... - r1 = rcu_dereference(i1) - r2 = a[r1 && force_zero_index]; /* BUGGY!!! */ + p = rcu_dereference(gp) + q = &global_q; + q += p != &oom_p1 && p != &oom_p2; + r1 = *q; /* BUGGY!!! */ The reason this is buggy is that "&&" and "||" are often compiled using branches. While weak-memory machines such as ARM or PowerPC @@ -94,14 +84,15 @@ o Do not use the results from relational operators ("==", "!=", ">", ">=", "<", or "<=") when dereferencing. For example, the following (quite strange) code is buggy: - int a[2]; - int index; - int flip_index = 0; + int *p; + int *q; ... - r1 = rcu_dereference(i1) - r2 = a[r1 != flip_index]; /* BUGGY!!! */ + p = rcu_dereference(gp) + q = &global_q; + q += p > &oom_p; + r1 = *q; /* BUGGY!!! */ As before, the reason this is buggy is that relational operators are often compiled using branches. And as before, although @@ -193,6 +184,11 @@ o Be very careful about comparing pointers obtained from pointer. Note that the volatile cast in rcu_dereference() will normally prevent the compiler from knowing too much. + However, please note that if the compiler knows that the + pointer takes on only one of two values, a not-equal + comparison will provide exactly the information that the + compiler needs to deduce the value of the pointer. + o Disable any value-speculation optimizations that your compiler might provide, especially if you are making use of feedback-based optimizations that take data collected from prior runs. Such diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 88dfce182f66..5746b0c77f3e 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -256,7 +256,9 @@ rcu_dereference() If you are going to be fetching multiple fields from the RCU-protected structure, using the local variable is of course preferred. Repeated rcu_dereference() calls look - ugly and incur unnecessary overhead on Alpha CPUs. + ugly, do not guarantee that the same pointer will be returned + if an update happened while in the critical section, and incur + unnecessary overhead on Alpha CPUs. Note that the value returned by rcu_dereference() is valid only within the enclosing RCU read-side critical section. @@ -879,9 +881,7 @@ SRCU: Initialization/cleanup All: lockdep-checked RCU-protected pointer access - rcu_access_index rcu_access_pointer - rcu_dereference_index_check rcu_dereference_raw rcu_lockdep_assert rcu_sleep_check diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 61ab1628a057..0b7f3e7a029c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2992,11 +2992,34 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Set maximum number of finished RCU callbacks to process in one batch. + rcutree.dump_tree= [KNL] + Dump the structure of the rcu_node combining tree + out at early boot. This is used for diagnostic + purposes, to verify correct tree setup. + + rcutree.gp_cleanup_delay= [KNL] + Set the number of jiffies to delay each step of + RCU grace-period cleanup. This only has effect + when CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP is set. + rcutree.gp_init_delay= [KNL] Set the number of jiffies to delay each step of RCU grace-period initialization. This only has - effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT is - set. + effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT + is set. + + rcutree.gp_preinit_delay= [KNL] + Set the number of jiffies to delay each step of + RCU grace-period pre-initialization, that is, + the propagation of recent CPU-hotplug changes up + the rcu_node combining tree. This only has effect + when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set. + + rcutree.rcu_fanout_exact= [KNL] + Disable autobalancing of the rcu_node combining + tree. This is used by rcutorture, and might + possibly be useful for architectures having high + cache-to-cache transfer latencies. rcutree.rcu_fanout_leaf= [KNL] Increase the number of CPUs assigned to each @@ -3101,7 +3124,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. test, hence the "fake". rcutorture.nreaders= [KNL] - Set number of RCU readers. + Set number of RCU readers. The value -1 selects + N-1, where N is the number of CPUs. A value + "n" less than -1 selects N-n-2, where N is again + the number of CPUs. For example, -2 selects N + (the number of CPUs), -3 selects N+1, and so on. rcutorture.object_debug= [KNL] Enable debug-object double-call_rcu() testing. diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index a3014bcc5b08..360841da3744 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1795,10 +1795,9 @@ for each construct. These operations all imply certain barriers: Memory operations issued before the ACQUIRE may be completed after the ACQUIRE operation has completed. An smp_mb__before_spinlock(), - combined with a following ACQUIRE, orders prior loads against - subsequent loads and stores and also orders prior stores against - subsequent stores. Note that this is weaker than smp_mb()! The - smp_mb__before_spinlock() primitive is free on many architectures. + combined with a following ACQUIRE, orders prior stores against + subsequent loads and stores. Note that this is weaker than smp_mb()! + The smp_mb__before_spinlock() primitive is free on many architectures. (2) RELEASE operation implication: diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index e535533d5ab8..d4298feaa6fb 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -53,9 +53,12 @@ static DEFINE_MUTEX(mce_chrdev_read_mutex); #define rcu_dereference_check_mce(p) \ - rcu_dereference_index_check((p), \ - rcu_read_lock_sched_held() || \ - lockdep_is_held(&mce_chrdev_read_mutex)) +({ \ + rcu_lockdep_assert(rcu_read_lock_sched_held() || \ + lockdep_is_held(&mce_chrdev_read_mutex), \ + "suspicious rcu_dereference_check_mce() usage"); \ + smp_load_acquire(&(p)); \ +}) #define CREATE_TRACE_POINTS #include <trace/events/mce.h> @@ -1884,7 +1887,7 @@ out: static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait) { poll_wait(file, &mce_chrdev_wait, wait); - if (rcu_access_index(mcelog.next)) + if (READ_ONCE(mcelog.next)) return POLLIN | POLLRDNORM; if (!mce_apei_read_done && apei_check_mce()) return POLLIN | POLLRDNORM; @@ -1929,8 +1932,8 @@ void register_mce_write_callback(ssize_t (*fn)(struct file *filp, } EXPORT_SYMBOL_GPL(register_mce_write_callback); -ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf, - size_t usize, loff_t *off) +static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf, + size_t usize, loff_t *off) { if (mce_write) return mce_write(filp, ubuf, usize, off); diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 5ec20bc4af76..03a899aabd17 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -292,10 +292,6 @@ void rcu_sched_qs(void); void rcu_bh_qs(void); void rcu_check_callbacks(int user); struct notifier_block; -void rcu_idle_enter(void); -void rcu_idle_exit(void); -void rcu_irq_enter(void); -void rcu_irq_exit(void); int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu); @@ -628,21 +624,6 @@ static inline void rcu_preempt_sleep_check(void) ((typeof(*p) __force __kernel *)(p)); \ }) -#define __rcu_access_index(p, space) \ -({ \ - typeof(p) _________p1 = READ_ONCE(p); \ - rcu_dereference_sparse(p, space); \ - (_________p1); \ -}) -#define __rcu_dereference_index_check(p, c) \ -({ \ - /* Dependency order vs. p above. */ \ - typeof(p) _________p1 = lockless_dereference(p); \ - rcu_lockdep_assert(c, \ - "suspicious rcu_dereference_index_check() usage"); \ - (_________p1); \ -}) - /** * RCU_INITIALIZER() - statically initialize an RCU-protected global variable * @v: The value to statically initialize with. @@ -787,41 +768,6 @@ static inline void rcu_preempt_sleep_check(void) #define rcu_dereference_raw_notrace(p) __rcu_dereference_check((p), 1, __rcu) /** - * rcu_access_index() - fetch RCU index with no dereferencing - * @p: The index to read - * - * Return the value of the specified RCU-protected index, but omit the - * smp_read_barrier_depends() and keep the READ_ONCE(). This is useful - * when the value of this index is accessed, but the index is not - * dereferenced, for example, when testing an RCU-protected index against - * -1. Although rcu_access_index() may also be used in cases where - * update-side locks prevent the value of the index from changing, you - * should instead use rcu_dereference_index_protected() for this use case. - */ -#define rcu_access_index(p) __rcu_access_index((p), __rcu) - -/** - * rcu_dereference_index_check() - rcu_dereference for indices with debug checking - * @p: The pointer to read, prior to dereferencing - * @c: The conditions under which the dereference will take place - * - * Similar to rcu_dereference_check(), but omits the sparse checking. - * This allows rcu_dereference_index_check() to be used on integers, - * which can then be used as array indices. Attempting to use - * rcu_dereference_check() on an integer will give compiler warnings - * because the sparse address-space mechanism relies on dereferencing - * the RCU-protected pointer. Dereferencing integers is not something - * that even gcc will put up with. - * - * Note that this function does not implicitly check for RCU read-side - * critical sections. If this function gains lots of uses, it might - * make sense to provide versions for each flavor of RCU, but it does - * not make sense as of early 2010. - */ -#define rcu_dereference_index_check(p, c) \ - __rcu_dereference_index_check((p), (c)) - -/** * rcu_dereference_protected() - fetch RCU pointer when updates prevented * @p: The pointer to read, prior to dereferencing * @c: The conditions under which the dereference will take place diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 937edaeb150d..3df6c1ec4e25 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -159,6 +159,22 @@ static inline void rcu_cpu_stall_reset(void) { } +static inline void rcu_idle_enter(void) +{ +} + +static inline void rcu_idle_exit(void) +{ +} + +static inline void rcu_irq_enter(void) +{ +} + +static inline void rcu_irq_exit(void) +{ +} + static inline void exit_rcu(void) { } diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 0bd400b02430..3fa4a43ab415 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -91,6 +91,11 @@ void rcu_force_quiescent_state(void); void rcu_bh_force_quiescent_state(void); void rcu_sched_force_quiescent_state(void); +void rcu_idle_enter(void); +void rcu_idle_exit(void); +void rcu_irq_enter(void); +void rcu_irq_exit(void); + void exit_rcu(void); void rcu_scheduler_starting(void); diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 3e18379dfa6f..0063b24b4f36 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -120,7 +120,7 @@ do { \ /* * Despite its name it doesn't necessarily has to be a full barrier. * It should only guarantee that a STORE before the critical section - * can not be reordered with a LOAD inside this section. + * can not be reordered with LOADs and STOREs inside this section. * spin_lock() is the one-way barrier, this LOAD can not escape out * of the region. So the default implementation simply ensures that * a STORE can not move into the critical section, smp_wmb() should diff --git a/init/Kconfig b/init/Kconfig index dc24dec60232..4c08197044f1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -465,13 +465,9 @@ endmenu # "CPU/Task time and stats accounting" menu "RCU Subsystem" -choice - prompt "RCU Implementation" - default TREE_RCU - config TREE_RCU - bool "Tree-based hierarchical RCU" - depends on !PREEMPT && SMP + bool + default y if !PREEMPT && SMP help This option selects the RCU implementation that is designed for very large SMP system with hundreds or @@ -479,8 +475,8 @@ config TREE_RCU smaller systems. config PREEMPT_RCU - bool "Preemptible tree-based hierarchical RCU" - depends on PREEMPT + bool + default y if PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -491,15 +487,28 @@ config PREEMPT_RCU Select this option if you are unsure. config TINY_RCU - bool "UP-only small-memory-footprint RCU" - depends on !PREEMPT && !SMP + bool + default y if !PREEMPT && !SMP help This option selects the RCU implementation that is designed for UP systems from which real-time response is not required. This option greatly reduces the memory footprint of RCU. -endchoice +config RCU_EXPERT + bool "Make expert-level adjustments to RCU configuration" + default n + help + This option needs to be enabled if you wish to make + expert-level adjustments to RCU configuration. By default, + no such adjustments can be made, which has the often-beneficial + side-effect of preventing "make oldconfig" from asking you all + sorts of detailed questions about how you would like numerous + obscure RCU options to be set up. + + Say Y if you need to make expert-level adjustments to RCU. + + Say N if you are unsure. config SRCU bool @@ -509,7 +518,7 @@ config SRCU sections. config TASKS_RCU - bool "Task_based RCU implementation using voluntary context switch" + bool default n select SRCU help @@ -517,8 +526,6 @@ config TASKS_RCU only voluntary context switch (not preemption!), idle, and user-mode execution as quiescent states. - If unsure, say N. - config RCU_STALL_COMMON def_bool ( TREE_RCU || PREEMPT_RCU || RCU_TRACE ) help @@ -531,9 +538,7 @@ config CONTEXT_TRACKING bool config RCU_USER_QS - bool "Consider userspace as in RCU extended quiescent state" - depends on HAVE_CONTEXT_TRACKING && SMP - select CONTEXT_TRACKING + bool help This option sets hooks on kernel / userspace boundaries and puts RCU in extended quiescent state when the CPU runs in @@ -541,12 +546,6 @@ config RCU_USER_QS excluded from the global RCU state machine and thus doesn't try to keep the timer tick on for RCU. - Unless you want to hack and help the development of the full - dynticks mode, you shouldn't enable this option. It also - adds unnecessary overhead. - - If unsure say N - config CONTEXT_TRACKING_FORCE bool "Force context tracking" depends on CONTEXT_TRACKING @@ -578,7 +577,7 @@ config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" range 2 64 if 64BIT range 2 32 if !64BIT - depends on TREE_RCU || PREEMPT_RCU + depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT default 64 if 64BIT default 32 if !64BIT help @@ -596,9 +595,9 @@ config RCU_FANOUT config RCU_FANOUT_LEAF int "Tree-based hierarchical RCU leaf-level fanout value" - range 2 RCU_FANOUT if 64BIT - range 2 RCU_FANOUT if !64BIT - depends on TREE_RCU || PREEMPT_RCU + range 2 64 if 64BIT + range 2 32 if !64BIT + depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT default 16 help This option controls the leaf-level fanout of hierarchical @@ -621,23 +620,9 @@ config RCU_FANOUT_LEAF Take the default if unsure. -config RCU_FANOUT_EXACT - bool "Disable tree-based hierarchical RCU auto-balancing" - depends on TREE_RCU || PREEMPT_RCU - default n - help - This option forces use of the exact RCU_FANOUT value specified, - regardless of imbalances in the hierarchy. This is useful for - testing RCU itself, and might one day be useful on systems with - strong NUMA behavior. - - Without RCU_FANOUT_EXACT, the code will balance the hierarchy. - - Say N if unsure. - config RCU_FAST_NO_HZ bool "Accelerate last non-dyntick-idle CPU's grace periods" - depends on NO_HZ_COMMON && SMP + depends on NO_HZ_COMMON && SMP && RCU_EXPERT default n help This option permits CPUs to enter dynticks-idle state even if @@ -663,7 +648,7 @@ config TREE_RCU_TRACE config RCU_BOOST bool "Enable RCU priority boosting" - depends on RT_MUTEXES && PREEMPT_RCU + depends on RT_MUTEXES && PREEMPT_RCU && RCU_EXPERT default n help This option boosts the priority of preempted RCU readers that @@ -680,6 +665,7 @@ config RCU_KTHREAD_PRIO range 0 99 if !RCU_BOOST default 1 if RCU_BOOST default 0 if !RCU_BOOST + depends on RCU_EXPERT help This option specifies the SCHED_FIFO priority value that will be assigned to the rcuc/n and rcub/n threads and is also the value diff --git a/kernel/cpu.c b/kernel/cpu.c index 94bbe4695232..9c9c9fab16cc 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -398,7 +398,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); if (err) { /* CPU didn't die: tell everyone. Can't complain. */ - smpboot_unpark_threads(cpu); cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); goto out_release; } @@ -463,6 +462,7 @@ static int smpboot_thread_call(struct notifier_block *nfb, switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DOWN_FAILED: case CPU_ONLINE: smpboot_unpark_threads(cpu); break; @@ -479,7 +479,7 @@ static struct notifier_block smpboot_thread_notifier = { .priority = CPU_PRI_SMPBOOT, }; -void __cpuinit smpboot_thread_init(void) +void smpboot_thread_init(void) { register_cpu_notifier(&smpboot_thread_notifier); } diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index ec8cce259779..32244186f1f2 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -122,12 +122,12 @@ static int torture_lock_busted_write_lock(void) static void torture_lock_busted_write_delay(struct torture_random_state *trsp) { - const unsigned long longdelay_us = 100; + const unsigned long longdelay_ms = 100; /* We want a long delay occasionally to force massive contention. */ if (!(torture_random(trsp) % - (cxt.nrealwriters_stress * 2000 * longdelay_us))) - mdelay(longdelay_us); + (cxt.nrealwriters_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms); #ifdef CONFIG_PREEMPT if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) preempt_schedule(); /* Allow test to be preempted. */ @@ -160,14 +160,14 @@ static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) static void torture_spin_lock_write_delay(struct torture_random_state *trsp) { const unsigned long shortdelay_us = 2; - const unsigned long longdelay_us = 100; + const unsigned long longdelay_ms = 100; /* We want a short delay mostly to emulate likely code, and * we want a long delay occasionally to force massive contention. */ if (!(torture_random(trsp) % - (cxt.nrealwriters_stress * 2000 * longdelay_us))) - mdelay(longdelay_us); + (cxt.nrealwriters_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms); if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 2 * shortdelay_us))) udelay(shortdelay_us); @@ -309,7 +309,7 @@ static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) static void torture_rwlock_read_unlock_irq(void) __releases(torture_rwlock) { - write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); + read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); } static struct lock_torture_ops rw_lock_irq_ops = { diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index a67ef6ff86b0..59e32684c23b 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -241,6 +241,7 @@ rcu_torture_free(struct rcu_torture *p) struct rcu_torture_ops { int ttype; void (*init)(void); + void (*cleanup)(void); int (*readlock)(void); void (*read_delay)(struct torture_random_state *rrsp); void (*readunlock)(int idx); @@ -477,10 +478,12 @@ static struct rcu_torture_ops rcu_busted_ops = { */ DEFINE_STATIC_SRCU(srcu_ctl); +static struct srcu_struct srcu_ctld; +static struct srcu_struct *srcu_ctlp = &srcu_ctl; -static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) +static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) { - return srcu_read_lock(&srcu_ctl); + return srcu_read_lock(srcu_ctlp); } static void srcu_read_delay(struct torture_random_state *rrsp) @@ -499,49 +502,49 @@ static void srcu_read_delay(struct torture_random_state *rrsp) rcu_read_delay(rrsp); } -static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) +static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) { - srcu_read_unlock(&srcu_ctl, idx); + srcu_read_unlock(srcu_ctlp, idx); } static unsigned long srcu_torture_completed(void) { - return srcu_batches_completed(&srcu_ctl); + return srcu_batches_completed(srcu_ctlp); } static void srcu_torture_deferred_free(struct rcu_torture *rp) { - call_srcu(&srcu_ctl, &rp->rtort_rcu, rcu_torture_cb); + call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); } static void srcu_torture_synchronize(void) { - synchronize_srcu(&srcu_ctl); + synchronize_srcu(srcu_ctlp); } static void srcu_torture_call(struct rcu_head *head, void (*func)(struct rcu_head *head)) { - call_srcu(&srcu_ctl, head, func); + call_srcu(srcu_ctlp, head, func); } static void srcu_torture_barrier(void) { - srcu_barrier(&srcu_ctl); + srcu_barrier(srcu_ctlp); } static void srcu_torture_stats(void) { int cpu; - int idx = srcu_ctl.completed & 0x1; + int idx = srcu_ctlp->completed & 0x1; pr_alert("%s%s per-CPU(idx=%d):", torture_type, TORTURE_FLAG, idx); for_each_possible_cpu(cpu) { long c0, c1; - c0 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx]; - c1 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]; + 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]; pr_cont(" %d(%ld,%ld)", cpu, c0, c1); } pr_cont("\n"); @@ -549,7 +552,7 @@ static void srcu_torture_stats(void) static void srcu_torture_synchronize_expedited(void) { - synchronize_srcu_expedited(&srcu_ctl); + synchronize_srcu_expedited(srcu_ctlp); } static struct rcu_torture_ops srcu_ops = { @@ -569,6 +572,38 @@ static struct rcu_torture_ops srcu_ops = { .name = "srcu" }; +static void srcu_torture_init(void) +{ + rcu_sync_torture_init(); + WARN_ON(init_srcu_struct(&srcu_ctld)); + srcu_ctlp = &srcu_ctld; +} + +static void srcu_torture_cleanup(void) +{ + cleanup_srcu_struct(&srcu_ctld); + srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ +} + +/* As above, but dynamically allocated. */ +static struct rcu_torture_ops srcud_ops = { + .ttype = SRCU_FLAVOR, + .init = srcu_torture_init, + .cleanup = srcu_torture_cleanup, + .readlock = srcu_torture_read_lock, + .read_delay = srcu_read_delay, + .readunlock = srcu_torture_read_unlock, + .started = NULL, + .completed = srcu_torture_completed, + .deferred_free = srcu_torture_deferred_free, + .sync = srcu_torture_synchronize, + .exp_sync = srcu_torture_synchronize_expedited, + .call = srcu_torture_call, + .cb_barrier = srcu_torture_barrier, + .stats = srcu_torture_stats, + .name = "srcud" +}; + /* * Definitions for sched torture testing. */ @@ -672,8 +707,8 @@ static void rcu_torture_boost_cb(struct rcu_head *head) struct rcu_boost_inflight *rbip = container_of(head, struct rcu_boost_inflight, rcu); - smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */ - rbip->inflight = 0; + /* Ensure RCU-core accesses precede clearing ->inflight */ + smp_store_release(&rbip->inflight, 0); } static int rcu_torture_boost(void *arg) @@ -710,9 +745,9 @@ static int rcu_torture_boost(void *arg) call_rcu_time = jiffies; while (ULONG_CMP_LT(jiffies, endtime)) { /* If we don't have a callback in flight, post one. */ - if (!rbi.inflight) { - smp_mb(); /* RCU core before ->inflight = 1. */ - rbi.inflight = 1; + if (!smp_load_acquire(&rbi.inflight)) { + /* RCU core before ->inflight = 1. */ + smp_store_release(&rbi.inflight, 1); call_rcu(&rbi.rcu, rcu_torture_boost_cb); if (jiffies - call_rcu_time > test_boost_duration * HZ - HZ / 2) { @@ -751,11 +786,10 @@ checkwait: stutter_wait("rcu_torture_boost"); } while (!torture_must_stop()); /* Clean up and exit. */ - while (!kthread_should_stop() || rbi.inflight) { + while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) { torture_shutdown_absorb("rcu_torture_boost"); schedule_timeout_uninterruptible(1); } - smp_mb(); /* order accesses to ->inflight before stack-frame death. */ destroy_rcu_head_on_stack(&rbi.rcu); torture_kthread_stopping("rcu_torture_boost"); return 0; @@ -1054,7 +1088,7 @@ static void rcu_torture_timer(unsigned long unused) p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || rcu_read_lock_sched_held() || - srcu_read_lock_held(&srcu_ctl)); + srcu_read_lock_held(srcu_ctlp)); if (p == NULL) { /* Leave because rcu_torture_writer is not yet underway */ cur_ops->readunlock(idx); @@ -1128,7 +1162,7 @@ rcu_torture_reader(void *arg) p = rcu_dereference_check(rcu_torture_current, rcu_read_lock_bh_held() || rcu_read_lock_sched_held() || - srcu_read_lock_held(&srcu_ctl)); + srcu_read_lock_held(srcu_ctlp)); if (p == NULL) { /* Wait for rcu_torture_writer to get underway */ cur_ops->readunlock(idx); @@ -1413,12 +1447,15 @@ static int rcu_torture_barrier_cbs(void *arg) do { wait_event(barrier_cbs_wq[myid], (newphase = - READ_ONCE(barrier_phase)) != lastphase || + smp_load_acquire(&barrier_phase)) != lastphase || torture_must_stop()); lastphase = newphase; - smp_mb(); /* ensure barrier_phase load before ->call(). */ if (torture_must_stop()) break; + /* + * The above smp_load_acquire() ensures barrier_phase load + * is ordered before the folloiwng ->call(). + */ cur_ops->call(&rcu, rcu_torture_barrier_cbf); if (atomic_dec_and_test(&barrier_cbs_count)) wake_up(&barrier_wq); @@ -1439,8 +1476,8 @@ static int rcu_torture_barrier(void *arg) do { atomic_set(&barrier_cbs_invoked, 0); atomic_set(&barrier_cbs_count, n_barrier_cbs); - smp_mb(); /* Ensure barrier_phase after prior assignments. */ - barrier_phase = !barrier_phase; + /* Ensure barrier_phase ordered after prior assignments. */ + smp_store_release(&barrier_phase, !barrier_phase); for (i = 0; i < n_barrier_cbs; i++) wake_up(&barrier_cbs_wq[i]); wait_event(barrier_wq, @@ -1588,10 +1625,14 @@ rcu_torture_cleanup(void) rcutorture_booster_cleanup(i); } - /* Wait for all RCU callbacks to fire. */ - + /* + * Wait for all RCU callbacks to fire, then do flavor-specific + * cleanup operations. + */ if (cur_ops->cb_barrier != NULL) cur_ops->cb_barrier(); + if (cur_ops->cleanup != NULL) + cur_ops->cleanup(); rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ @@ -1668,8 +1709,8 @@ rcu_torture_init(void) int cpu; int firsterr = 0; static struct rcu_torture_ops *torture_ops[] = { - &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &sched_ops, - RCUTORTURE_TASKS_OPS + &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, + &sched_ops, RCUTORTURE_TASKS_OPS }; if (!torture_init_begin(torture_type, verbose, &torture_runnable)) @@ -1701,7 +1742,7 @@ rcu_torture_init(void) if (nreaders >= 0) { nrealreaders = nreaders; } else { - nrealreaders = num_online_cpus() - 1; + nrealreaders = num_online_cpus() - 2 - nreaders; if (nrealreaders <= 0) nrealreaders = 1; } diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index 069742d61c68..591af0cb7b9f 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -49,39 +49,6 @@ static void __call_rcu(struct rcu_head *head, #include "tiny_plugin.h" -/* - * Enter idle, which is an extended quiescent state if we have fully - * entered that mode. - */ -void rcu_idle_enter(void) -{ -} -EXPORT_SYMBOL_GPL(rcu_idle_enter); - -/* - * Exit an interrupt handler towards idle. - */ -void rcu_irq_exit(void) -{ -} -EXPORT_SYMBOL_GPL(rcu_irq_exit); - -/* - * Exit idle, so that we are no longer in an extended quiescent state. - */ -void rcu_idle_exit(void) -{ -} -EXPORT_SYMBOL_GPL(rcu_idle_exit); - -/* - * Enter an interrupt handler, moving away from idle. - */ -void rcu_irq_enter(void) -{ -} -EXPORT_SYMBOL_GPL(rcu_irq_enter); - #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) /* @@ -170,6 +137,11 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp) /* Move the ready-to-invoke callbacks to a local list. */ local_irq_save(flags); + if (rcp->donetail == &rcp->rcucblist) { + /* No callbacks ready, so just leave. */ + local_irq_restore(flags); + return; + } RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1)); list = rcp->rcucblist; rcp->rcucblist = *rcp->donetail; diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 7b9dd4f62569..add042926a66 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -114,8 +114,14 @@ static struct rcu_state *const rcu_state_p; static struct rcu_data __percpu *const rcu_data_p; LIST_HEAD(rcu_struct_flavors); -/* Increase (but not decrease) the CONFIG_RCU_FANOUT_LEAF at boot time. */ -static int rcu_fanout_leaf = CONFIG_RCU_FANOUT_LEAF; +/* Dump rcu_node combining tree at boot to verify correct setup. */ +static bool dump_tree; +module_param(dump_tree, bool, 0444); +/* Control rcu_node-tree auto-balancing at boot time. */ +static bool rcu_fanout_exact; +module_param(rcu_fanout_exact, bool, 0444); +/* Increase (but not decrease) the RCU_FANOUT_LEAF at boot time. */ +static int rcu_fanout_leaf = RCU_FANOUT_LEAF; module_param(rcu_fanout_leaf, int, 0444); int rcu_num_lvls __read_mostly = RCU_NUM_LVLS; static int num_rcu_lvl[] = { /* Number of rcu_nodes at specified level. */ @@ -160,17 +166,46 @@ static void invoke_rcu_core(void); static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp); /* rcuc/rcub kthread realtime priority */ +#ifdef CONFIG_RCU_KTHREAD_PRIO static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO; +#else /* #ifdef CONFIG_RCU_KTHREAD_PRIO */ +static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0; +#endif /* #else #ifdef CONFIG_RCU_KTHREAD_PRIO */ module_param(kthread_prio, int, 0644); /* Delay in jiffies for grace-period initialization delays, debug only. */ + +#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT +static int gp_preinit_delay = CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT_DELAY; +module_param(gp_preinit_delay, int, 0644); +#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT */ +static const int gp_preinit_delay; +#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT */ + #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT static int gp_init_delay = CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY; module_param(gp_init_delay, int, 0644); #else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */ static const int gp_init_delay; #endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */ -#define PER_RCU_NODE_PERIOD 10 /* Number of grace periods between delays. */ + +#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP +static int gp_cleanup_delay = CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY; +module_param(gp_cleanup_delay, int, 0644); +#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP */ +static const int gp_cleanup_delay; +#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP */ + +/* + * Number of grace periods between delays, normalized by the duration of + * the delay. The longer the the delay, the more the grace periods between + * each delay. The reason for this normalization is that it means that, + * for non-zero delays, the overall slowdown of grace periods is constant + * regardless of the duration of the delay. This arrangement balances + * the need for long delays to increase some race probabilities with the + * need for fast grace periods to increase other race probabilities. + */ +#define PER_RCU_NODE_PERIOD 3 /* Number of grace periods between delays. */ /* * Track the rcutorture test sequence number and the update version @@ -586,7 +621,8 @@ static void rcu_eqs_enter_common(long long oldval, bool user) struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks); trace_rcu_dyntick(TPS("Start"), oldval, rdtp->dynticks_nesting); - if (!user && !is_idle_task(current)) { + if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + !user && !is_idle_task(current)) { struct task_struct *idle __maybe_unused = idle_task(smp_processor_id()); @@ -605,7 +641,8 @@ static void rcu_eqs_enter_common(long long oldval, bool user) smp_mb__before_atomic(); /* See above. */ atomic_inc(&rdtp->dynticks); smp_mb__after_atomic(); /* Force ordering with next sojourn. */ - WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + atomic_read(&rdtp->dynticks) & 0x1); rcu_dynticks_task_enter(); /* @@ -631,7 +668,8 @@ static void rcu_eqs_enter(bool user) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; - WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + (oldval & DYNTICK_TASK_NEST_MASK) == 0); if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE) { rdtp->dynticks_nesting = 0; rcu_eqs_enter_common(oldval, user); @@ -704,7 +742,8 @@ void rcu_irq_exit(void) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting--; - WARN_ON_ONCE(rdtp->dynticks_nesting < 0); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + rdtp->dynticks_nesting < 0); if (rdtp->dynticks_nesting) trace_rcu_dyntick(TPS("--="), oldval, rdtp->dynticks_nesting); else @@ -729,10 +768,12 @@ static void rcu_eqs_exit_common(long long oldval, int user) 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(!(atomic_read(&rdtp->dynticks) & 0x1)); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + !(atomic_read(&rdtp->dynticks) & 0x1)); rcu_cleanup_after_idle(); trace_rcu_dyntick(TPS("End"), oldval, rdtp->dynticks_nesting); - if (!user && !is_idle_task(current)) { + if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + !user && !is_idle_task(current)) { struct task_struct *idle __maybe_unused = idle_task(smp_processor_id()); @@ -756,7 +797,7 @@ static void rcu_eqs_exit(bool user) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; - WARN_ON_ONCE(oldval < 0); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && oldval < 0); if (oldval & DYNTICK_TASK_NEST_MASK) { rdtp->dynticks_nesting += DYNTICK_TASK_NEST_VALUE; } else { @@ -829,7 +870,8 @@ void rcu_irq_enter(void) rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting++; - WARN_ON_ONCE(rdtp->dynticks_nesting == 0); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && + rdtp->dynticks_nesting == 0); if (oldval) trace_rcu_dyntick(TPS("++="), oldval, rdtp->dynticks_nesting); else @@ -1734,6 +1776,13 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp) rcu_gp_kthread_wake(rsp); } +static void rcu_gp_slow(struct rcu_state *rsp, int delay) +{ + if (delay > 0 && + !(rsp->gpnum % (rcu_num_nodes * PER_RCU_NODE_PERIOD * delay))) + schedule_timeout_uninterruptible(delay); +} + /* * Initialize a new grace period. Return 0 if no grace period required. */ @@ -1776,6 +1825,7 @@ static int rcu_gp_init(struct rcu_state *rsp) * will handle subsequent offline CPUs. */ rcu_for_each_leaf_node(rsp, rnp) { + rcu_gp_slow(rsp, gp_preinit_delay); raw_spin_lock_irq(&rnp->lock); smp_mb__after_unlock_lock(); if (rnp->qsmaskinit == rnp->qsmaskinitnext && @@ -1832,6 +1882,7 @@ static int rcu_gp_init(struct rcu_state *rsp) * process finishes, because this kthread handles both. */ rcu_for_each_node_breadth_first(rsp, rnp) { + rcu_gp_slow(rsp, gp_init_delay); raw_spin_lock_irq(&rnp->lock); smp_mb__after_unlock_lock(); rdp = this_cpu_ptr(rsp->rda); @@ -1849,9 +1900,6 @@ static int rcu_gp_init(struct rcu_state *rsp) raw_spin_unlock_irq(&rnp->lock); cond_resched_rcu_qs(); WRITE_ONCE(rsp->gp_activity, jiffies); - if (gp_init_delay > 0 && - !(rsp->gpnum % (rcu_num_nodes * PER_RCU_NODE_PERIOD))) - schedule_timeout_uninterruptible(gp_init_delay); } return 1; @@ -1946,6 +1994,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp) raw_spin_unlock_irq(&rnp->lock); cond_resched_rcu_qs(); WRITE_ONCE(rsp->gp_activity, jiffies); + rcu_gp_slow(rsp, gp_cleanup_delay); } rnp = rcu_get_root(rsp); raw_spin_lock_irq(&rnp->lock); @@ -2338,8 +2387,6 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp) rcu_report_qs_rdp(rdp->cpu, rsp, rdp); } -#ifdef CONFIG_HOTPLUG_CPU - /* * Send the specified CPU's RCU callbacks to the orphanage. The * specified CPU must be offline, and the caller must hold the @@ -2350,7 +2397,7 @@ rcu_send_cbs_to_orphanage(int cpu, struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp) { /* No-CBs CPUs do not have orphanable callbacks. */ - if (rcu_is_nocb_cpu(rdp->cpu)) + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU) || rcu_is_nocb_cpu(rdp->cpu)) return; /* @@ -2409,7 +2456,8 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp, unsigned long flags) struct rcu_data *rdp = raw_cpu_ptr(rsp->rda); /* No-CBs CPUs are handled specially. */ - if (rcu_nocb_adopt_orphan_cbs(rsp, rdp, flags)) + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU) || + rcu_nocb_adopt_orphan_cbs(rsp, rdp, flags)) return; /* Do the accounting first. */ @@ -2456,6 +2504,9 @@ static void rcu_cleanup_dying_cpu(struct rcu_state *rsp) RCU_TRACE(struct rcu_data *rdp = this_cpu_ptr(rsp->rda)); RCU_TRACE(struct rcu_node *rnp = rdp->mynode); + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) + return; + RCU_TRACE(mask = rdp->grpmask); trace_rcu_grace_period(rsp->name, rnp->gpnum + 1 - !!(rnp->qsmask & mask), @@ -2484,7 +2535,8 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf) long mask; struct rcu_node *rnp = rnp_leaf; - if (rnp->qsmaskinit || rcu_preempt_has_tasks(rnp)) + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU) || + rnp->qsmaskinit || rcu_preempt_has_tasks(rnp)) return; for (;;) { mask = rnp->grpmask; @@ -2515,6 +2567,9 @@ static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp) struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */ + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) + return; + /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ mask = rdp->grpmask; raw_spin_lock_irqsave(&rnp->lock, flags); @@ -2536,6 +2591,9 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */ + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) + return; + /* Adjust any no-longer-needed kthreads. */ rcu_boost_kthread_setaffinity(rnp, -1); @@ -2550,26 +2608,6 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) cpu, rdp->qlen, rdp->nxtlist); } -#else /* #ifdef CONFIG_HOTPLUG_CPU */ - -static void rcu_cleanup_dying_cpu(struct rcu_state *rsp) -{ -} - -static void __maybe_unused rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf) -{ -} - -static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp) -{ -} - -static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) -{ -} - -#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ - /* * Invoke any RCU callbacks that have made it to the end of their grace * period. Thottle as specified by rdp->blimit. @@ -2734,10 +2772,6 @@ static void force_qs_rnp(struct rcu_state *rsp, mask = 0; raw_spin_lock_irqsave(&rnp->lock, flags); smp_mb__after_unlock_lock(); - if (!rcu_gp_in_progress(rsp)) { - raw_spin_unlock_irqrestore(&rnp->lock, flags); - return; - } if (rnp->qsmask == 0) { if (rcu_state_p == &rcu_sched_state || rsp != rcu_state_p || @@ -2767,8 +2801,6 @@ static void force_qs_rnp(struct rcu_state *rsp, bit = 1; for (; cpu <= rnp->grphi; cpu++, bit <<= 1) { if ((rnp->qsmask & bit) != 0) { - if ((rnp->qsmaskinit & bit) == 0) - *isidle = false; /* Pending hotplug. */ if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj)) mask |= bit; } @@ -3783,7 +3815,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp) rdp->gpnum = rnp->completed; /* Make CPU later note any new GP. */ rdp->completed = rnp->completed; rdp->passed_quiesce = false; - rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr); + rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu); rdp->qs_pending = false; trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl")); raw_spin_unlock_irqrestore(&rnp->lock, flags); @@ -3927,16 +3959,16 @@ void rcu_scheduler_starting(void) /* * Compute the per-level fanout, either using the exact fanout specified - * or balancing the tree, depending on CONFIG_RCU_FANOUT_EXACT. + * or balancing the tree, depending on the rcu_fanout_exact boot parameter. */ static void __init rcu_init_levelspread(struct rcu_state *rsp) { int i; - if (IS_ENABLED(CONFIG_RCU_FANOUT_EXACT)) { + if (rcu_fanout_exact) { rsp->levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf; for (i = rcu_num_lvls - 2; i >= 0; i--) - rsp->levelspread[i] = CONFIG_RCU_FANOUT; + rsp->levelspread[i] = RCU_FANOUT; } else { int ccur; int cprv; @@ -3974,9 +4006,9 @@ static void __init rcu_init_one(struct rcu_state *rsp, BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */ - /* Silence gcc 4.8 warning about array index out of range. */ - if (rcu_num_lvls > RCU_NUM_LVLS) - panic("rcu_init_one: rcu_num_lvls overflow"); + /* Silence gcc 4.8 false positive about array index out of range. */ + if (rcu_num_lvls <= 0 || rcu_num_lvls > RCU_NUM_LVLS) + panic("rcu_init_one: rcu_num_lvls out of range"); /* Initialize the level-tracking arrays. */ @@ -4062,7 +4094,7 @@ static void __init rcu_init_geometry(void) jiffies_till_next_fqs = d; /* If the compile-time values are accurate, just leave. */ - if (rcu_fanout_leaf == CONFIG_RCU_FANOUT_LEAF && + if (rcu_fanout_leaf == RCU_FANOUT_LEAF && nr_cpu_ids == NR_CPUS) return; pr_info("RCU: Adjusting geometry for rcu_fanout_leaf=%d, nr_cpu_ids=%d\n", @@ -4076,7 +4108,7 @@ static void __init rcu_init_geometry(void) rcu_capacity[0] = 1; rcu_capacity[1] = rcu_fanout_leaf; for (i = 2; i <= MAX_RCU_LVLS; i++) - rcu_capacity[i] = rcu_capacity[i - 1] * CONFIG_RCU_FANOUT; + rcu_capacity[i] = rcu_capacity[i - 1] * RCU_FANOUT; /* * The boot-time rcu_fanout_leaf parameter is only permitted @@ -4086,7 +4118,7 @@ static void __init rcu_init_geometry(void) * the configured number of CPUs. Complain and fall back to the * compile-time values if these limits are exceeded. */ - if (rcu_fanout_leaf < CONFIG_RCU_FANOUT_LEAF || + if (rcu_fanout_leaf < RCU_FANOUT_LEAF || rcu_fanout_leaf > sizeof(unsigned long) * 8 || n > rcu_capacity[MAX_RCU_LVLS]) { WARN_ON(1); @@ -4112,6 +4144,28 @@ static void __init rcu_init_geometry(void) rcu_num_nodes -= n; } +/* + * Dump out the structure of the rcu_node combining tree associated + * with the rcu_state structure referenced by rsp. + */ +static void __init rcu_dump_rcu_node_tree(struct rcu_state *rsp) +{ + int level = 0; + struct rcu_node *rnp; + + pr_info("rcu_node tree layout dump\n"); + pr_info(" "); + rcu_for_each_node_breadth_first(rsp, rnp) { + if (rnp->level != level) { + pr_cont("\n"); + pr_info(" "); + level = rnp->level; + } + pr_cont("%d:%d ^%d ", rnp->grplo, rnp->grphi, rnp->grpnum); + } + pr_cont("\n"); +} + void __init rcu_init(void) { int cpu; @@ -4122,6 +4176,8 @@ void __init rcu_init(void) rcu_init_geometry(); rcu_init_one(&rcu_bh_state, &rcu_bh_data); rcu_init_one(&rcu_sched_state, &rcu_sched_data); + if (dump_tree) + rcu_dump_rcu_node_tree(&rcu_sched_state); __rcu_init_preempt(); open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 8079c5b22a8f..4adb7ca0bf47 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -35,11 +35,33 @@ * In practice, this did work well going from three levels to four. * Of course, your mileage may vary. */ + #define MAX_RCU_LVLS 4 -#define RCU_FANOUT_1 (CONFIG_RCU_FANOUT_LEAF) -#define RCU_FANOUT_2 (RCU_FANOUT_1 * CONFIG_RCU_FANOUT) -#define RCU_FANOUT_3 (RCU_FANOUT_2 * CONFIG_RCU_FANOUT) -#define RCU_FANOUT_4 (RCU_FANOUT_3 * CONFIG_RCU_FANOUT) + +#ifdef CONFIG_RCU_FANOUT +#define RCU_FANOUT CONFIG_RCU_FANOUT +#else /* #ifdef CONFIG_RCU_FANOUT */ +# ifdef CONFIG_64BIT +# define RCU_FANOUT 64 +# else +# define RCU_FANOUT 32 +# endif +#endif /* #else #ifdef CONFIG_RCU_FANOUT */ + +#ifdef CONFIG_RCU_FANOUT_LEAF +#define RCU_FANOUT_LEAF CONFIG_RCU_FANOUT_LEAF +#else /* #ifdef CONFIG_RCU_FANOUT_LEAF */ +# ifdef CONFIG_64BIT +# define RCU_FANOUT_LEAF 64 +# else +# define RCU_FANOUT_LEAF 32 +# endif +#endif /* #else #ifdef CONFIG_RCU_FANOUT_LEAF */ + +#define RCU_FANOUT_1 (RCU_FANOUT_LEAF) +#define RCU_FANOUT_2 (RCU_FANOUT_1 * RCU_FANOUT) +#define RCU_FANOUT_3 (RCU_FANOUT_2 * RCU_FANOUT) +#define RCU_FANOUT_4 (RCU_FANOUT_3 * RCU_FANOUT) #if NR_CPUS <= RCU_FANOUT_1 # define RCU_NUM_LVLS 1 diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 853c7b8ea833..32664347091a 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -70,11 +70,11 @@ static void __init rcu_bootup_announce_oddness(void) { if (IS_ENABLED(CONFIG_RCU_TRACE)) pr_info("\tRCU debugfs-based tracing is enabled.\n"); - if ((IS_ENABLED(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 64) || - (!IS_ENABLED(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 32)) + if ((IS_ENABLED(CONFIG_64BIT) && RCU_FANOUT != 64) || + (!IS_ENABLED(CONFIG_64BIT) && RCU_FANOUT != 32)) pr_info("\tCONFIG_RCU_FANOUT set to non-default value of %d\n", - CONFIG_RCU_FANOUT); - if (IS_ENABLED(CONFIG_RCU_FANOUT_EXACT)) + RCU_FANOUT); + if (rcu_fanout_exact) pr_info("\tHierarchical RCU autobalancing is disabled.\n"); if (IS_ENABLED(CONFIG_RCU_FAST_NO_HZ)) pr_info("\tRCU dyntick-idle grace-period acceleration is enabled.\n"); @@ -86,10 +86,10 @@ static void __init rcu_bootup_announce_oddness(void) pr_info("\tAdditional per-CPU info printed with stalls.\n"); if (NUM_RCU_LVL_4 != 0) pr_info("\tFour-level hierarchy is enabled.\n"); - if (CONFIG_RCU_FANOUT_LEAF != 16) + if (RCU_FANOUT_LEAF != 16) pr_info("\tBuild-time adjustment of leaf fanout to %d.\n", - CONFIG_RCU_FANOUT_LEAF); - if (rcu_fanout_leaf != CONFIG_RCU_FANOUT_LEAF) + RCU_FANOUT_LEAF); + if (rcu_fanout_leaf != RCU_FANOUT_LEAF) pr_info("\tBoot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf); if (nr_cpu_ids != NR_CPUS) pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids); @@ -315,9 +315,11 @@ void rcu_read_unlock_special(struct task_struct *t) t->rcu_read_unlock_special.b.blocked = false; /* - * Remove this task from the list it blocked on. The - * task can migrate while we acquire the lock, but at - * most one time. So at most two passes through loop. + * Remove this task from the list it blocked on. The task + * now remains queued on the rcu_node corresponding to + * the CPU it first blocked on, so the first attempt to + * acquire the task's rcu_node's ->lock will succeed. + * Keep the loop and add a WARN_ON() out of sheer paranoia. */ for (;;) { rnp = t->rcu_blocked_node; @@ -325,6 +327,7 @@ void rcu_read_unlock_special(struct task_struct *t) smp_mb__after_unlock_lock(); if (rnp == t->rcu_blocked_node) break; + WARN_ON_ONCE(1); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } empty_norm = !rcu_preempt_blocked_readers_cgp(rnp); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ba2b0c87e65b..b908048f8d6a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1233,6 +1233,7 @@ config RCU_TORTURE_TEST depends on DEBUG_KERNEL select TORTURE_TEST select SRCU + select TASKS_RCU default n help This option provides a kernel module that runs torture tests @@ -1261,12 +1262,38 @@ config RCU_TORTURE_TEST_RUNNABLE Say N here if you want the RCU torture tests to start only after being manually enabled via /proc. +config RCU_TORTURE_TEST_SLOW_PREINIT + bool "Slow down RCU grace-period pre-initialization to expose races" + depends on RCU_TORTURE_TEST + help + This option delays grace-period pre-initialization (the + propagation of CPU-hotplug changes up the rcu_node combining + tree) for a few jiffies between initializing each pair of + consecutive rcu_node structures. This helps to expose races + involving grace-period pre-initialization, in other words, it + makes your kernel less stable. It can also greatly increase + grace-period latency, especially on systems with large numbers + of CPUs. This is useful when torture-testing RCU, but in + almost no other circumstance. + + Say Y here if you want your system to crash and hang more often. + Say N if you want a sane system. + +config RCU_TORTURE_TEST_SLOW_PREINIT_DELAY + int "How much to slow down RCU grace-period pre-initialization" + range 0 5 + default 3 + depends on RCU_TORTURE_TEST_SLOW_PREINIT + help + This option specifies the number of jiffies to wait between + each rcu_node structure pre-initialization step. + config RCU_TORTURE_TEST_SLOW_INIT bool "Slow down RCU grace-period initialization to expose races" depends on RCU_TORTURE_TEST help - This option makes grace-period initialization block for a - few jiffies between initializing each pair of consecutive + This option delays grace-period initialization for a few + jiffies between initializing each pair of consecutive rcu_node structures. This helps to expose races involving grace-period initialization, in other words, it makes your kernel less stable. It can also greatly increase grace-period @@ -1286,6 +1313,30 @@ config RCU_TORTURE_TEST_SLOW_INIT_DELAY This option specifies the number of jiffies to wait between each rcu_node structure initialization. +config RCU_TORTURE_TEST_SLOW_CLEANUP + bool "Slow down RCU grace-period cleanup to expose races" + depends on RCU_TORTURE_TEST + help + This option delays grace-period cleanup for a few jiffies + between cleaning up each pair of consecutive rcu_node + structures. This helps to expose races involving grace-period + cleanup, in other words, it makes your kernel less stable. + It can also greatly increase grace-period latency, especially + on systems with large numbers of CPUs. This is useful when + torture-testing RCU, but in almost no other circumstance. + + Say Y here if you want your system to crash and hang more often. + Say N if you want a sane system. + +config RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY + int "How much to slow down RCU grace-period cleanup" + range 0 5 + default 3 + depends on RCU_TORTURE_TEST_SLOW_CLEANUP + help + This option specifies the number of jiffies to wait between + each rcu_node structure cleanup operation. + config RCU_CPU_STALL_TIMEOUT int "RCU CPU stall timeout in seconds" depends on RCU_STALL_COMMON @@ -1322,6 +1373,17 @@ config RCU_TRACE Say Y here if you want to enable RCU tracing Say N if you are unsure. +config RCU_EQS_DEBUG + bool "Use this when adding any sort of NO_HZ support to your arch" + depends on DEBUG_KERNEL + help + This option provides consistency checks in RCU's handling of + NO_HZ. These checks have proven quite helpful in detecting + bugs in arch-specific NO_HZ code. + + Say N here if you need ultimate kernel/user switch latencies + Say Y if you are unsure + endmenu # "RCU Debugging" config DEBUG_BLOCK_EXT_DEVT diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh index 15f1a17ca96e..3f81a1095206 100755 --- a/tools/testing/selftests/rcutorture/bin/configinit.sh +++ b/tools/testing/selftests/rcutorture/bin/configinit.sh @@ -66,7 +66,7 @@ make $buildloc $TORTURE_DEFCONFIG > $builddir/Make.defconfig.out 2>&1 mv $builddir/.config $builddir/.config.sav sh $T/upd.sh < $builddir/.config.sav > $builddir/.config cp $builddir/.config $builddir/.config.new -yes '' | make $buildloc oldconfig > $builddir/Make.modconfig.out 2>&1 +yes '' | make $buildloc oldconfig > $builddir/Make.oldconfig.out 2> $builddir/Make.oldconfig.err # verify new config matches specification. configcheck.sh $builddir/.config $c diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh index 4f5b20f367a9..d86bdd6b6cc2 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh @@ -43,6 +43,10 @@ do if test -f "$i/console.log" then configcheck.sh $i/.config $i/ConfigFragment + if test -r $i/Make.oldconfig.err + then + cat $i/Make.oldconfig.err + fi parse-build.sh $i/Make.out $configfile parse-torture.sh $i/console.log $configfile parse-console.sh $i/console.log $configfile diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh index dd2812ceb0ba..fbe2dbff1e21 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm.sh @@ -55,7 +55,7 @@ usage () { echo " --bootargs kernel-boot-arguments" echo " --bootimage relative-path-to-kernel-boot-image" echo " --buildonly" - echo " --configs \"config-file list\"" + echo " --configs \"config-file list w/ repeat factor (3*TINY01)\"" echo " --cpus N" echo " --datestamp string" echo " --defconfig string" @@ -178,13 +178,26 @@ fi touch $T/cfgcpu for CF in $configs do - if test -f "$CONFIGFRAG/$CF" + case $CF in + [0-9]\**|[0-9][0-9]\**|[0-9][0-9][0-9]\**) + config_reps=`echo $CF | sed -e 's/\*.*$//'` + CF1=`echo $CF | sed -e 's/^[^*]*\*//'` + ;; + *) + config_reps=1 + CF1=$CF + ;; + esac + if test -f "$CONFIGFRAG/$CF1" then - cpu_count=`configNR_CPUS.sh $CONFIGFRAG/$CF` - cpu_count=`configfrag_boot_cpus "$TORTURE_BOOTARGS" "$CONFIGFRAG/$CF" "$cpu_count"` - echo $CF $cpu_count >> $T/cfgcpu + cpu_count=`configNR_CPUS.sh $CONFIGFRAG/$CF1` + cpu_count=`configfrag_boot_cpus "$TORTURE_BOOTARGS" "$CONFIGFRAG/$CF1" "$cpu_count"` + for ((cur_rep=0;cur_rep<$config_reps;cur_rep++)) + do + echo $CF1 $cpu_count >> $T/cfgcpu + done else - echo "The --configs file $CF does not exist, terminating." + echo "The --configs file $CF1 does not exist, terminating." exit 1 fi done diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon index 49701218dc62..f824b4c9d9d9 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon +++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon @@ -1,3 +1,5 @@ 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 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N index 9fbb41b9b314..1a087c3c8bb8 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N @@ -5,3 +5,4 @@ CONFIG_HOTPLUG_CPU=y CONFIG_PREEMPT_NONE=y CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P index 4b6f272dba27..4837430a71c0 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P @@ -5,3 +5,4 @@ CONFIG_HOTPLUG_CPU=y CONFIG_PREEMPT_NONE=n CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=y +#CHECK#CONFIG_RCU_EXPERT=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot index 238bfe3bd0cc..84a7d51b7481 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot @@ -1 +1 @@ -rcutorture.torture_type=srcu +rcutorture.torture_type=srcud diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS01 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS01 index 97f0a0b27ef7..2cc0e60eba6e 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS01 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS01 @@ -5,5 +5,6 @@ CONFIG_PREEMPT_NONE=n CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=y CONFIG_DEBUG_LOCK_ALLOC=y -CONFIG_PROVE_RCU=y -CONFIG_TASKS_RCU=y +CONFIG_PROVE_LOCKING=n +#CHECK#CONFIG_PROVE_RCU=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS02 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS02 index 696d2ea74d13..ad2be91e5ee7 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS02 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS02 @@ -2,4 +2,3 @@ CONFIG_SMP=n CONFIG_PREEMPT_NONE=y CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=n -CONFIG_TASKS_RCU=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TASKS03 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS03 index 9c60da5b5d1d..c70c51d5ded1 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TASKS03 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TASKS03 @@ -6,8 +6,8 @@ CONFIG_HIBERNATION=n CONFIG_PREEMPT_NONE=n CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=y -CONFIG_TASKS_RCU=y CONFIG_HZ_PERIODIC=n CONFIG_NO_HZ_IDLE=n CONFIG_NO_HZ_FULL=y CONFIG_NO_HZ_FULL_ALL=y +#CHECK#CONFIG_RCU_EXPERT=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TINY02 b/tools/testing/selftests/rcutorture/configs/rcu/TINY02 index 36e41df3d27a..f1892e0371c9 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TINY02 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TINY02 @@ -8,7 +8,7 @@ CONFIG_NO_HZ_IDLE=n CONFIG_NO_HZ_FULL=n CONFIG_RCU_TRACE=y CONFIG_PROVE_LOCKING=y -CONFIG_PROVE_RCU=y +#CHECK#CONFIG_PROVE_RCU=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_PREEMPT_COUNT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TINY02.boot b/tools/testing/selftests/rcutorture/configs/rcu/TINY02.boot index 0f0802730014..6c1a292a65fb 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TINY02.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/TINY02.boot @@ -1,2 +1,3 @@ rcupdate.rcu_self_test=1 rcupdate.rcu_self_test_bh=1 +rcutorture.torture_type=rcu_bh diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 index f8a10a7500c6..8e9137f66831 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01 @@ -16,3 +16,4 @@ CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02 b/tools/testing/selftests/rcutorture/configs/rcu/TREE02 index 629122fb8b4a..aeea6a204d14 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02 @@ -14,10 +14,10 @@ CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_FANOUT=3 CONFIG_RCU_FANOUT_LEAF=3 -CONFIG_RCU_FANOUT_EXACT=n CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=n CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T index a25de47888a4..2ac9e68ea3d1 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T @@ -14,7 +14,6 @@ CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_FANOUT=3 CONFIG_RCU_FANOUT_LEAF=3 -CONFIG_RCU_FANOUT_EXACT=n CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 index 53f24e0a0ab6..72aa7d87ea99 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03 @@ -1,5 +1,5 @@ CONFIG_SMP=y -CONFIG_NR_CPUS=8 +CONFIG_NR_CPUS=16 CONFIG_PREEMPT_NONE=n CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=y @@ -9,12 +9,12 @@ CONFIG_NO_HZ_IDLE=n CONFIG_NO_HZ_FULL=n CONFIG_RCU_TRACE=y CONFIG_HOTPLUG_CPU=y -CONFIG_RCU_FANOUT=4 -CONFIG_RCU_FANOUT_LEAF=4 -CONFIG_RCU_FANOUT_EXACT=n +CONFIG_RCU_FANOUT=2 +CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=y CONFIG_RCU_KTHREAD_PRIO=2 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot new file mode 100644 index 000000000000..120c0c88d100 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot @@ -0,0 +1 @@ +rcutorture.onoff_interval=1 rcutorture.onoff_holdoff=30 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 index 0f84db35b36d..3f5112751cda 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE04 @@ -13,10 +13,10 @@ CONFIG_RCU_TRACE=y CONFIG_HOTPLUG_CPU=n CONFIG_SUSPEND=n CONFIG_HIBERNATION=n -CONFIG_RCU_FANOUT=2 -CONFIG_RCU_FANOUT_LEAF=2 -CONFIG_RCU_FANOUT_EXACT=n +CONFIG_RCU_FANOUT=4 +CONFIG_RCU_FANOUT_LEAF=4 CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=y +CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 index 212e3bfd2b2a..c04dfea6fd21 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 @@ -12,11 +12,11 @@ CONFIG_RCU_TRACE=n CONFIG_HOTPLUG_CPU=y CONFIG_RCU_FANOUT=6 CONFIG_RCU_FANOUT_LEAF=6 -CONFIG_RCU_FANOUT_EXACT=n CONFIG_RCU_NOCB_CPU=y CONFIG_RCU_NOCB_CPU_NONE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y -CONFIG_PROVE_RCU=y +#CHECK#CONFIG_PROVE_RCU=y CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06 index 7eee63b44218..f51d2c73a68e 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE06 @@ -14,10 +14,10 @@ CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_FANOUT=6 CONFIG_RCU_FANOUT_LEAF=6 -CONFIG_RCU_FANOUT_EXACT=y CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y -CONFIG_PROVE_RCU=y +#CHECK#CONFIG_PROVE_RCU=y CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=y +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE06.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE06.boot index da9a03a398db..dd90f28ed700 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE06.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE06.boot @@ -1,3 +1,4 @@ rcupdate.rcu_self_test=1 rcupdate.rcu_self_test_bh=1 rcupdate.rcu_self_test_sched=1 +rcutree.rcu_fanout_exact=1 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE07 b/tools/testing/selftests/rcutorture/configs/rcu/TREE07 index 92a97fa97dec..f422af4ff5a3 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE07 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE07 @@ -15,8 +15,8 @@ CONFIG_RCU_TRACE=y CONFIG_HOTPLUG_CPU=y CONFIG_RCU_FANOUT=2 CONFIG_RCU_FANOUT_LEAF=2 -CONFIG_RCU_FANOUT_EXACT=n CONFIG_RCU_NOCB_CPU=n CONFIG_DEBUG_LOCK_ALLOC=n -CONFIG_RCU_CPU_STALL_INFO=y +CONFIG_RCU_CPU_STALL_INFO=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08 index 5812027d6f9f..a24d2ca30646 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08 @@ -1,5 +1,5 @@ CONFIG_SMP=y -CONFIG_NR_CPUS=16 +CONFIG_NR_CPUS=8 CONFIG_PREEMPT_NONE=n CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=y @@ -13,13 +13,13 @@ CONFIG_HOTPLUG_CPU=n CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_FANOUT=3 -CONFIG_RCU_FANOUT_EXACT=y 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 -CONFIG_PROVE_RCU=y +#CHECK#CONFIG_PROVE_RCU=y CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T index 3eaeccacb083..b2b8cea69dc9 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T @@ -13,7 +13,6 @@ CONFIG_HOTPLUG_CPU=n CONFIG_SUSPEND=n CONFIG_HIBERNATION=n CONFIG_RCU_FANOUT=3 -CONFIG_RCU_FANOUT_EXACT=y CONFIG_RCU_FANOUT_LEAF=2 CONFIG_RCU_NOCB_CPU=y CONFIG_RCU_NOCB_CPU_ALL=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T.boot new file mode 100644 index 000000000000..883149b5f2d1 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T.boot @@ -0,0 +1 @@ +rcutree.rcu_fanout_exact=1 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot index 2561daf605ad..fb066dc82769 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot @@ -1,3 +1,4 @@ rcutorture.torture_type=sched rcupdate.rcu_self_test=1 rcupdate.rcu_self_test_sched=1 +rcutree.rcu_fanout_exact=1 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 index 6076b36f6c0b..aa4ed08d999d 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 @@ -16,3 +16,4 @@ CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_CPU_STALL_INFO=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +#CHECK#CONFIG_RCU_EXPERT=n diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt index ec03c883db00..b24c0004fc49 100644 --- a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt +++ b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt @@ -12,13 +12,12 @@ CONFIG_NO_HZ_IDLE -- Do those not otherwise specified. (Groups of two.) CONFIG_NO_HZ_FULL -- Do two, one with CONFIG_NO_HZ_FULL_SYSIDLE. CONFIG_NO_HZ_FULL_SYSIDLE -- Do one. CONFIG_PREEMPT -- Do half. (First three and #8.) -CONFIG_PROVE_LOCKING -- Do all but two, covering CONFIG_PROVE_RCU and not. -CONFIG_PROVE_RCU -- Do all but one under CONFIG_PROVE_LOCKING. +CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not. +CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING. CONFIG_RCU_BOOST -- one of PREEMPT_RCU. CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing. -CONFIG_RCU_CPU_STALL_INFO -- Do one. -CONFIG_RCU_FANOUT -- Cover hierarchy as currently, but overlap with others. -CONFIG_RCU_FANOUT_EXACT -- Do one. +CONFIG_RCU_CPU_STALL_INFO -- Now default, avoid at least twice. +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 CONFIG_RCU_NOCB_CPU_ALL. CONFIG_RCU_NOCB_CPU -- Do three, see below. @@ -27,28 +26,19 @@ 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. RCU-bh: Do one with PREEMPT and one with !PREEMPT. RCU-sched: Do one with PREEMPT but not BOOST. -Hierarchy: - -TREE01. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=8, CONFIG_RCU_FANOUT_EXACT=n. -TREE02. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=3, CONFIG_RCU_FANOUT_EXACT=n, - CONFIG_RCU_FANOUT_LEAF=3. -TREE03. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=4, CONFIG_RCU_FANOUT_EXACT=n, - CONFIG_RCU_FANOUT_LEAF=4. -TREE04. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=2, CONFIG_RCU_FANOUT_EXACT=n, - CONFIG_RCU_FANOUT_LEAF=2. -TREE05. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=6, CONFIG_RCU_FANOUT_EXACT=n - CONFIG_RCU_FANOUT_LEAF=6. -TREE06. CONFIG_NR_CPUS=8, CONFIG_RCU_FANOUT=6, CONFIG_RCU_FANOUT_EXACT=y - CONFIG_RCU_FANOUT_LEAF=6. -TREE07. CONFIG_NR_CPUS=16, CONFIG_RCU_FANOUT=2, CONFIG_RCU_FANOUT_EXACT=n, - CONFIG_RCU_FANOUT_LEAF=2. -TREE08. CONFIG_NR_CPUS=16, CONFIG_RCU_FANOUT=3, CONFIG_RCU_FANOUT_EXACT=y, - CONFIG_RCU_FANOUT_LEAF=2. -TREE09. CONFIG_NR_CPUS=1. +Boot parameters: + +nohz_full - do at least one. +maxcpu -- do at least one. +rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not. +rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not. +rcupdate.rcu_self_test -- Do at least one each, offloaded and not. +rcutree.rcu_fanout_exact -- Do at least one. Kconfig Parameters Ignored: |