diff options
45 files changed, 484 insertions, 262 deletions
diff --git a/Documentation/RCU/rcuref.txt b/Documentation/RCU/rcuref.txt index 613033ff2b9b..5e6429d66c24 100644 --- a/Documentation/RCU/rcuref.txt +++ b/Documentation/RCU/rcuref.txt @@ -12,6 +12,7 @@ please read on. Reference counting on elements of lists which are protected by traditional reader/writer spinlocks or semaphores are straightforward: +CODE LISTING A: 1. 2. add() search_and_reference() { { @@ -28,7 +29,8 @@ add() search_and_reference() release_referenced() delete() { { ... write_lock(&list_lock); - atomic_dec(&el->rc, relfunc) ... + if(atomic_dec_and_test(&el->rc)) ... + kfree(el); ... remove_element } write_unlock(&list_lock); ... @@ -44,6 +46,7 @@ search_and_reference() could potentially hold reference to an element which has already been deleted from the list/array. Use atomic_inc_not_zero() in this scenario as follows: +CODE LISTING B: 1. 2. add() search_and_reference() { { @@ -79,6 +82,7 @@ search_and_reference() code path. In such cases, the atomic_dec_and_test() may be moved from delete() to el_free() as follows: +CODE LISTING C: 1. 2. add() search_and_reference() { { @@ -114,6 +118,17 @@ element can therefore safely be freed. This in turn guarantees that if any reader finds the element, that reader may safely acquire a reference without checking the value of the reference counter. +A clear advantage of the RCU-based pattern in listing C over the one +in listing B is that any call to search_and_reference() that locates +a given object will succeed in obtaining a reference to that object, +even given a concurrent invocation of delete() for that same object. +Similarly, a clear advantage of both listings B and C over listing A is +that a call to delete() is not delayed even if there are an arbitrarily +large number of calls to search_and_reference() searching for the same +object that delete() was invoked on. Instead, all that is delayed is +the eventual invocation of kfree(), which is usually not a problem on +modern computer systems, even the small ones. + In cases where delete() can sleep, synchronize_rcu() can be called from delete(), so that el_free() can be subsumed into delete as follows: @@ -130,3 +145,7 @@ delete() kfree(el); ... } + +As additional examples in the kernel, the pattern in listing C is used by +reference counting of struct pid, while the pattern in listing B is used by +struct posix_acl. diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index 1ab70c37921f..13e88fc00f01 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt @@ -153,7 +153,7 @@ rcupdate.rcu_task_stall_timeout This boot/sysfs parameter controls the RCU-tasks stall warning interval. A value of zero or less suppresses RCU-tasks stall warnings. A positive value sets the stall-warning interval - in jiffies. An RCU-tasks stall warning starts with the line: + in seconds. An RCU-tasks stall warning starts with the line: INFO: rcu_tasks detected stalls on tasks: diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 981651a8b65d..7e1a8721637a 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -212,7 +212,7 @@ synchronize_rcu() rcu_assign_pointer() - typeof(p) rcu_assign_pointer(p, typeof(p) v); + void rcu_assign_pointer(p, typeof(p) v); Yes, rcu_assign_pointer() -is- implemented as a macro, though it would be cool to be able to declare a function in this manner. @@ -220,9 +220,9 @@ rcu_assign_pointer() The updater uses this function to assign a new value to an RCU-protected pointer, in order to safely communicate the change - in value from the updater to the reader. This function returns - the new value, and also executes any memory-barrier instructions - required for a given CPU architecture. + in value from the updater to the reader. This macro does not + evaluate to an rvalue, but it does execute any memory-barrier + instructions required for a given CPU architecture. Perhaps just as important, it serves to document (1) which pointers are protected by RCU and (2) the point at which a diff --git a/Documentation/core-api/circular-buffers.rst b/Documentation/core-api/circular-buffers.rst index 53e51caa3347..50966f66e398 100644 --- a/Documentation/core-api/circular-buffers.rst +++ b/Documentation/core-api/circular-buffers.rst @@ -3,7 +3,7 @@ Circular Buffers ================ :Author: David Howells <dhowells@redhat.com> -:Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> +:Author: Paul E. McKenney <paulmck@linux.ibm.com> Linux provides a number of features that can be used to implement circular diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index f70ebcdfe592..e4e07c8ab89e 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -3,7 +3,7 @@ ============================ By: David Howells <dhowells@redhat.com> - Paul E. McKenney <paulmck@linux.vnet.ibm.com> + Paul E. McKenney <paulmck@linux.ibm.com> Will Deacon <will.deacon@arm.com> Peter Zijlstra <peterz@infradead.org> diff --git a/Documentation/translations/ko_KR/memory-barriers.txt b/Documentation/translations/ko_KR/memory-barriers.txt index db0b9d8619f1..5f3c74dcad43 100644 --- a/Documentation/translations/ko_KR/memory-barriers.txt +++ b/Documentation/translations/ko_KR/memory-barriers.txt @@ -24,7 +24,7 @@ Documentation/memory-barriers.txt ========================= 저자: David Howells <dhowells@redhat.com> - Paul E. McKenney <paulmck@linux.vnet.ibm.com> + Paul E. McKenney <paulmck@linux.ibm.com> Will Deacon <will.deacon@arm.com> Peter Zijlstra <peterz@infradead.org> diff --git a/include/linux/module.h b/include/linux/module.h index 188998d3dca9..1455812dd325 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -21,6 +21,7 @@ #include <linux/rbtree_latch.h> #include <linux/error-injection.h> #include <linux/tracepoint-defs.h> +#include <linux/srcu.h> #include <linux/percpu.h> #include <asm/module.h> @@ -450,6 +451,10 @@ struct module { unsigned int num_tracepoints; tracepoint_ptr_t *tracepoints_ptrs; #endif +#ifdef CONFIG_TREE_SRCU + unsigned int num_srcu_structs; + struct srcu_struct **srcu_struct_ptrs; +#endif #ifdef CONFIG_BPF_EVENTS unsigned int num_bpf_raw_events; struct bpf_raw_event_map *bpf_raw_events; diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 03cb4b6f842e..2809b44cbbee 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -17,14 +17,18 @@ struct percpu_rw_semaphore { int readers_block; }; -#define DEFINE_STATIC_PERCPU_RWSEM(name) \ +#define __DEFINE_PERCPU_RWSEM(name, is_static) \ static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name); \ -static struct percpu_rw_semaphore name = { \ - .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC), \ +is_static struct percpu_rw_semaphore name = { \ + .rss = __RCU_SYNC_INITIALIZER(name.rss), \ .read_count = &__percpu_rwsem_rc_##name, \ .rw_sem = __RWSEM_INITIALIZER(name.rw_sem), \ .writer = __RCUWAIT_INITIALIZER(name.writer), \ } +#define DEFINE_PERCPU_RWSEM(name) \ + __DEFINE_PERCPU_RWSEM(name, /* not static */) +#define DEFINE_STATIC_PERCPU_RWSEM(name) \ + __DEFINE_PERCPU_RWSEM(name, static) extern int __percpu_down_read(struct percpu_rw_semaphore *, int); extern void __percpu_up_read(struct percpu_rw_semaphore *); diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h index 6fc53a1345b3..9b83865d24f9 100644 --- a/include/linux/rcu_sync.h +++ b/include/linux/rcu_sync.h @@ -13,62 +13,44 @@ #include <linux/wait.h> #include <linux/rcupdate.h> -enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC }; - /* Structure to mediate between updaters and fastpath-using readers. */ struct rcu_sync { int gp_state; int gp_count; wait_queue_head_t gp_wait; - int cb_state; struct rcu_head cb_head; - - enum rcu_sync_type gp_type; }; -extern void rcu_sync_lockdep_assert(struct rcu_sync *); - /** * rcu_sync_is_idle() - Are readers permitted to use their fastpaths? * @rsp: Pointer to rcu_sync structure to use for synchronization * - * Returns true if readers are permitted to use their fastpaths. - * Must be invoked within an RCU read-side critical section whose - * flavor matches that of the rcu_sync struture. + * Returns true if readers are permitted to use their fastpaths. Must be + * invoked within some flavor of RCU read-side critical section. */ static inline bool rcu_sync_is_idle(struct rcu_sync *rsp) { -#ifdef CONFIG_PROVE_RCU - rcu_sync_lockdep_assert(rsp); -#endif - return !rsp->gp_state; /* GP_IDLE */ + RCU_LOCKDEP_WARN(!rcu_read_lock_held() && + !rcu_read_lock_bh_held() && + !rcu_read_lock_sched_held(), + "suspicious rcu_sync_is_idle() usage"); + return !READ_ONCE(rsp->gp_state); /* GP_IDLE */ } -extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type); +extern void rcu_sync_init(struct rcu_sync *); extern void rcu_sync_enter_start(struct rcu_sync *); extern void rcu_sync_enter(struct rcu_sync *); extern void rcu_sync_exit(struct rcu_sync *); extern void rcu_sync_dtor(struct rcu_sync *); -#define __RCU_SYNC_INITIALIZER(name, type) { \ +#define __RCU_SYNC_INITIALIZER(name) { \ .gp_state = 0, \ .gp_count = 0, \ .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \ - .cb_state = 0, \ - .gp_type = type, \ } -#define __DEFINE_RCU_SYNC(name, type) \ - struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type) - -#define DEFINE_RCU_SYNC(name) \ - __DEFINE_RCU_SYNC(name, RCU_SYNC) - -#define DEFINE_RCU_SCHED_SYNC(name) \ - __DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC) - -#define DEFINE_RCU_BH_SYNC(name) \ - __DEFINE_RCU_SYNC(name, RCU_BH_SYNC) +#define DEFINE_RCU_SYNC(name) \ + struct rcu_sync name = __RCU_SYNC_INITIALIZER(name) #endif /* _LINUX_RCU_SYNC_H_ */ diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 922bb6848813..0c9b92799abc 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -367,16 +367,15 @@ static inline void rcu_preempt_sleep_check(void) { } * other macros that it invokes. */ #define rcu_assign_pointer(p, v) \ -({ \ +do { \ uintptr_t _r_a_p__v = (uintptr_t)(v); \ - rcu_check_sparse(p, __rcu); \ + rcu_check_sparse(p, __rcu); \ \ if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \ WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \ else \ smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \ - _r_a_p__v; \ -}) +} while (0) /** * rcu_swap_protected() - swap an RCU and a regular pointer @@ -588,7 +587,7 @@ static inline void rcu_preempt_sleep_check(void) { } * read-side critical sections may be preempted and they may also block, but * only when acquiring spinlocks that are subject to priority inheritance. */ -static inline void rcu_read_lock(void) +static __always_inline void rcu_read_lock(void) { __rcu_read_lock(); __acquire(RCU); @@ -805,7 +804,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /** * kfree_rcu() - kfree an object after a grace period. * @ptr: pointer to kfree - * @rcu_head: the name of the struct rcu_head within the type of @ptr. + * @rhf: the name of the struct rcu_head within the type of @ptr. * * Many rcu callbacks functions just call kfree() on the base structure. * These functions are trivial, but their size adds up, and furthermore @@ -828,9 +827,13 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) * The BUILD_BUG_ON check must not involve any function calls, hence the * checks are done in macros here. */ -#define kfree_rcu(ptr, rcu_head) \ - __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) - +#define kfree_rcu(ptr, rhf) \ +do { \ + typeof (ptr) ___p = (ptr); \ + \ + if (___p) \ + __kfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \ +} while (0) /* * Place this after a lock-acquisition primitive to guarantee that diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 7f7c8c050f63..9cfcc8a756ae 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -120,9 +120,17 @@ struct srcu_struct { * * 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_data, name##_srcu_data);\ - is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_data) +#ifdef MODULE +# define __DEFINE_SRCU(name, is_static) \ + is_static struct srcu_struct name; \ + struct srcu_struct * const __srcu_struct_##name \ + __section("___srcu_struct_ptrs") = &name +#else +# define __DEFINE_SRCU(name, is_static) \ + static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data); \ + is_static struct srcu_struct name = \ + __SRCU_STRUCT_INIT(name, name##_srcu_data) +#endif #define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) #define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) diff --git a/include/linux/torture.h b/include/linux/torture.h index 23d80db426d7..a620118385bb 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -66,7 +66,7 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void)); /* Task stuttering, which forces load/no-load transitions. */ bool stutter_wait(const char *title); -int torture_stutter_init(int s); +int torture_stutter_init(int s, int sgap); /* Initialization and cleanup. */ bool torture_init_begin(char *ttype, int v); diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 217cec4e22c6..b112e93388dc 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -101,7 +101,7 @@ static DEFINE_SPINLOCK(cgroup_idr_lock); */ static DEFINE_SPINLOCK(cgroup_file_kn_lock); -struct percpu_rw_semaphore cgroup_threadgroup_rwsem; +DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem); #define cgroup_assert_mutex_or_rcu_locked() \ RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ @@ -5616,7 +5616,6 @@ int __init cgroup_init(void) int ssid; BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16); - BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem)); BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files)); BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files)); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 78f61bfc6b79..97c367f0a9aa 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -46,7 +46,7 @@ static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; #define uprobes_mmap_hash(v) (&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ]) -static struct percpu_rw_semaphore dup_mmap_sem; +DEFINE_STATIC_PERCPU_RWSEM(dup_mmap_sem); /* Have a copy of original instruction */ #define UPROBE_COPY_INSN 0 @@ -2302,7 +2302,5 @@ void __init uprobes_init(void) for (i = 0; i < UPROBES_HASH_SZ; i++) mutex_init(&uprobes_mmap_mutex[i]); - BUG_ON(percpu_init_rwsem(&dup_mmap_sem)); - BUG_ON(register_die_notifier(&uprobe_exception_nb)); } diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 80a463d31a8d..c513031cd7e3 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -975,7 +975,7 @@ static int __init lock_torture_init(void) goto unwind; } if (stutter > 0) { - firsterr = torture_stutter_init(stutter); + firsterr = torture_stutter_init(stutter, stutter); if (firsterr) goto unwind; } diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c index f17dad99eec8..48cab93a47fd 100644 --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -17,7 +17,7 @@ int __percpu_init_rwsem(struct percpu_rw_semaphore *sem, return -ENOMEM; /* ->rw_sem represents the whole percpu_rw_semaphore for lockdep */ - rcu_sync_init(&sem->rss, RCU_SCHED_SYNC); + rcu_sync_init(&sem->rss); __init_rwsem(&sem->rw_sem, name, rwsem_key); rcuwait_init(&sem->writer); sem->readers_block = 0; diff --git a/kernel/module.c b/kernel/module.c index 6e6712b3aaf5..c79a53b629b6 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3095,6 +3095,11 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->tracepoints_ptrs), &mod->num_tracepoints); #endif +#ifdef CONFIG_TREE_SRCU + mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", + sizeof(*mod->srcu_struct_ptrs), + &mod->num_srcu_structs); +#endif #ifdef CONFIG_BPF_EVENTS mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", sizeof(*mod->bpf_raw_events), diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 390aab20115e..5290b01de534 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -446,6 +446,7 @@ void rcu_request_urgent_qs_task(struct task_struct *t); enum rcutorture_type { RCU_FLAVOR, RCU_TASKS_FLAVOR, + RCU_TRIVIAL_FLAVOR, SRCU_FLAVOR, INVALID_RCU_FLAVOR }; @@ -479,6 +480,10 @@ void do_trace_rcu_torture_read(const char *rcutorturename, #endif #endif +#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST) +long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask); +#endif + #ifdef CONFIG_TINY_SRCU static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index efaa5b3f4d3f..fce4e7e6f502 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -299,6 +299,7 @@ struct rcu_torture_ops { int irq_capable; int can_boost; int extendables; + int slow_gps; const char *name; }; @@ -667,9 +668,51 @@ static struct rcu_torture_ops tasks_ops = { .fqs = NULL, .stats = NULL, .irq_capable = 1, + .slow_gps = 1, .name = "tasks" }; +/* + * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. + * This implementation does not necessarily work well with CPU hotplug. + */ + +static void synchronize_rcu_trivial(void) +{ + int cpu; + + for_each_online_cpu(cpu) { + rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu)); + WARN_ON_ONCE(raw_smp_processor_id() != cpu); + } +} + +static int rcu_torture_read_lock_trivial(void) __acquires(RCU) +{ + preempt_disable(); + return 0; +} + +static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU) +{ + preempt_enable(); +} + +static struct rcu_torture_ops trivial_ops = { + .ttype = RCU_TRIVIAL_FLAVOR, + .init = rcu_sync_torture_init, + .readlock = rcu_torture_read_lock_trivial, + .read_delay = rcu_read_delay, /* just reuse rcu's version. */ + .readunlock = rcu_torture_read_unlock_trivial, + .get_gp_seq = rcu_no_completed, + .sync = synchronize_rcu_trivial, + .exp_sync = synchronize_rcu_trivial, + .fqs = NULL, + .stats = NULL, + .irq_capable = 1, + .name = "trivial" +}; + static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) { if (!cur_ops->gp_diff) @@ -1010,10 +1053,17 @@ rcu_torture_writer(void *arg) !rcu_gp_is_normal(); } rcu_torture_writer_state = RTWS_STUTTER; - if (stutter_wait("rcu_torture_writer")) + if (stutter_wait("rcu_torture_writer") && + !READ_ONCE(rcu_fwd_cb_nodelay) && + !cur_ops->slow_gps && + !torture_must_stop()) for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) - if (list_empty(&rcu_tortures[i].rtort_free)) - WARN_ON_ONCE(1); + if (list_empty(&rcu_tortures[i].rtort_free) && + rcu_access_pointer(rcu_torture_current) != + &rcu_tortures[i]) { + rcu_ftrace_dump(DUMP_ALL); + WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); + } } while (!torture_must_stop()); /* Reset expediting back to unexpedited. */ if (expediting > 0) @@ -1358,8 +1408,9 @@ rcu_torture_stats_print(void) } pr_alert("%s%s ", torture_type, TORTURE_FLAG); - pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", + pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", rcu_torture_current, + rcu_torture_current ? "ver" : "VER", rcu_torture_current_version, list_empty(&rcu_torture_freelist), atomic_read(&n_rcu_torture_alloc), @@ -1661,6 +1712,17 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) spin_unlock_irqrestore(&rcu_fwd_lock, flags); } +// Give the scheduler a chance, even on nohz_full CPUs. +static void rcu_torture_fwd_prog_cond_resched(void) +{ + if (IS_ENABLED(CONFIG_PREEMPT) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { + if (need_resched()) + schedule(); + } else { + cond_resched(); + } +} + /* * Free all callbacks on the rcu_fwd_cb_head list, either because the * test is over or because we hit an OOM event. @@ -1674,16 +1736,18 @@ static unsigned long rcu_torture_fwd_prog_cbfree(void) for (;;) { spin_lock_irqsave(&rcu_fwd_lock, flags); rfcp = rcu_fwd_cb_head; - if (!rfcp) + if (!rfcp) { + spin_unlock_irqrestore(&rcu_fwd_lock, flags); break; + } rcu_fwd_cb_head = rfcp->rfc_next; if (!rcu_fwd_cb_head) rcu_fwd_cb_tail = &rcu_fwd_cb_head; spin_unlock_irqrestore(&rcu_fwd_lock, flags); kfree(rfcp); freed++; + rcu_torture_fwd_prog_cond_resched(); } - spin_unlock_irqrestore(&rcu_fwd_lock, flags); return freed; } @@ -1707,6 +1771,8 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries) } /* Tight loop containing cond_resched(). */ + WRITE_ONCE(rcu_fwd_cb_nodelay, true); + cur_ops->sync(); /* Later readers see above write. */ if (selfpropcb) { WRITE_ONCE(fcs.stop, 0); cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); @@ -1724,7 +1790,7 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries) udelay(10); cur_ops->readunlock(idx); if (!fwd_progress_need_resched || need_resched()) - cond_resched(); + rcu_torture_fwd_prog_cond_resched(); } (*tested_tries)++; if (!time_before(jiffies, stopat) && @@ -1745,6 +1811,8 @@ static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries) WARN_ON(READ_ONCE(fcs.stop) != 2); destroy_rcu_head_on_stack(&fcs.rh); } + schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ + WRITE_ONCE(rcu_fwd_cb_nodelay, false); } /* Carry out call_rcu() forward-progress testing. */ @@ -1765,6 +1833,8 @@ static void rcu_torture_fwd_prog_cr(void) if (READ_ONCE(rcu_fwd_emergency_stop)) return; /* Get out of the way quickly, no GP wait! */ + if (!cur_ops->call) + return; /* Can't do call_rcu() fwd prog without ->call. */ /* Loop continuously posting RCU callbacks. */ WRITE_ONCE(rcu_fwd_cb_nodelay, true); @@ -1805,7 +1875,7 @@ static void rcu_torture_fwd_prog_cr(void) rfcp->rfc_gps = 0; } cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); - cond_resched(); + rcu_torture_fwd_prog_cond_resched(); } stoppedat = jiffies; n_launders_cb_snap = READ_ONCE(n_launders_cb); @@ -1814,7 +1884,6 @@ static void rcu_torture_fwd_prog_cr(void) cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ (void)rcu_torture_fwd_prog_cbfree(); - WRITE_ONCE(rcu_fwd_cb_nodelay, false); if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop)) { WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED); pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n", @@ -1825,6 +1894,8 @@ static void rcu_torture_fwd_prog_cr(void) n_max_gps, n_max_cbs, cver, gps); rcu_torture_fwd_cb_hist(); } + schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ + WRITE_ONCE(rcu_fwd_cb_nodelay, false); } @@ -2240,7 +2311,7 @@ rcu_torture_init(void) int firsterr = 0; static struct rcu_torture_ops *torture_ops[] = { &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, - &busted_srcud_ops, &tasks_ops, + &busted_srcud_ops, &tasks_ops, &trivial_ops, }; if (!torture_init_begin(torture_type, verbose)) @@ -2363,7 +2434,10 @@ rcu_torture_init(void) if (stutter < 0) stutter = 0; if (stutter) { - firsterr = torture_stutter_init(stutter * HZ); + int t; + + t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; + firsterr = torture_stutter_init(stutter * HZ, t); if (firsterr) goto unwind; } diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 9b761e546de8..cf0e886314f2 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -831,8 +831,8 @@ static void srcu_leak_callback(struct rcu_head *rhp) * srcu_read_lock(), and srcu_read_unlock() that are all passed the same * srcu_struct structure. */ -void __call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp, - rcu_callback_t func, bool do_norm) +static void __call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp, + rcu_callback_t func, bool do_norm) { unsigned long flags; int idx; @@ -1310,3 +1310,68 @@ void __init srcu_init(void) queue_work(rcu_gp_wq, &ssp->work.work); } } + +#ifdef CONFIG_MODULES + +/* Initialize any global-scope srcu_struct structures used by this module. */ +static int srcu_module_coming(struct module *mod) +{ + int i; + struct srcu_struct **sspp = mod->srcu_struct_ptrs; + int ret; + + for (i = 0; i < mod->num_srcu_structs; i++) { + ret = init_srcu_struct(*(sspp++)); + if (WARN_ON_ONCE(ret)) + return ret; + } + return 0; +} + +/* Clean up any global-scope srcu_struct structures used by this module. */ +static void srcu_module_going(struct module *mod) +{ + int i; + struct srcu_struct **sspp = mod->srcu_struct_ptrs; + + for (i = 0; i < mod->num_srcu_structs; i++) + cleanup_srcu_struct(*(sspp++)); +} + +/* Handle one module, either coming or going. */ +static int srcu_module_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct module *mod = data; + int ret = 0; + + switch (val) { + case MODULE_STATE_COMING: + ret = srcu_module_coming(mod); + break; + case MODULE_STATE_GOING: + srcu_module_going(mod); + break; + default: + break; + } + return ret; +} + +static struct notifier_block srcu_module_nb = { + .notifier_call = srcu_module_notify, + .priority = 0, +}; + +static __init int init_srcu_module_notifier(void) +{ + int ret; + + ret = register_module_notifier(&srcu_module_nb); + if (ret) + pr_warn("Failed to register srcu module notifier\n"); + return ret; +} +late_initcall(init_srcu_module_notifier); + +#endif /* #ifdef CONFIG_MODULES */ diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index a8304d90573f..d4558ab7a07d 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -10,65 +10,18 @@ #include <linux/rcu_sync.h> #include <linux/sched.h> -#ifdef CONFIG_PROVE_RCU -#define __INIT_HELD(func) .held = func, -#else -#define __INIT_HELD(func) -#endif - -static const struct { - void (*sync)(void); - void (*call)(struct rcu_head *, void (*)(struct rcu_head *)); - void (*wait)(void); -#ifdef CONFIG_PROVE_RCU - int (*held)(void); -#endif -} gp_ops[] = { - [RCU_SYNC] = { - .sync = synchronize_rcu, - .call = call_rcu, - .wait = rcu_barrier, - __INIT_HELD(rcu_read_lock_held) - }, - [RCU_SCHED_SYNC] = { - .sync = synchronize_rcu, - .call = call_rcu, - .wait = rcu_barrier, - __INIT_HELD(rcu_read_lock_sched_held) - }, - [RCU_BH_SYNC] = { - .sync = synchronize_rcu, - .call = call_rcu, - .wait = rcu_barrier, - __INIT_HELD(rcu_read_lock_bh_held) - }, -}; - -enum { GP_IDLE = 0, GP_PENDING, GP_PASSED }; -enum { CB_IDLE = 0, CB_PENDING, CB_REPLAY }; +enum { GP_IDLE = 0, GP_ENTER, GP_PASSED, GP_EXIT, GP_REPLAY }; #define rss_lock gp_wait.lock -#ifdef CONFIG_PROVE_RCU -void rcu_sync_lockdep_assert(struct rcu_sync *rsp) -{ - RCU_LOCKDEP_WARN(!gp_ops[rsp->gp_type].held(), - "suspicious rcu_sync_is_idle() usage"); -} - -EXPORT_SYMBOL_GPL(rcu_sync_lockdep_assert); -#endif - /** * rcu_sync_init() - Initialize an rcu_sync structure * @rsp: Pointer to rcu_sync structure to be initialized - * @type: Flavor of RCU with which to synchronize rcu_sync structure */ -void rcu_sync_init(struct rcu_sync *rsp, enum rcu_sync_type type) +void rcu_sync_init(struct rcu_sync *rsp) { memset(rsp, 0, sizeof(*rsp)); init_waitqueue_head(&rsp->gp_wait); - rsp->gp_type = type; } /** @@ -86,56 +39,26 @@ void rcu_sync_enter_start(struct rcu_sync *rsp) rsp->gp_state = GP_PASSED; } -/** - * rcu_sync_enter() - Force readers onto slowpath - * @rsp: Pointer to rcu_sync structure to use for synchronization - * - * This function is used by updaters who need readers to make use of - * a slowpath during the update. After this function returns, all - * subsequent calls to rcu_sync_is_idle() will return false, which - * tells readers to stay off their fastpaths. A later call to - * rcu_sync_exit() re-enables reader slowpaths. - * - * When called in isolation, rcu_sync_enter() must wait for a grace - * period, however, closely spaced calls to rcu_sync_enter() can - * optimize away the grace-period wait via a state machine implemented - * by rcu_sync_enter(), rcu_sync_exit(), and rcu_sync_func(). - */ -void rcu_sync_enter(struct rcu_sync *rsp) -{ - bool need_wait, need_sync; - spin_lock_irq(&rsp->rss_lock); - need_wait = rsp->gp_count++; - need_sync = rsp->gp_state == GP_IDLE; - if (need_sync) - rsp->gp_state = GP_PENDING; - spin_unlock_irq(&rsp->rss_lock); +static void rcu_sync_func(struct rcu_head *rhp); - WARN_ON_ONCE(need_wait && need_sync); - if (need_sync) { - gp_ops[rsp->gp_type].sync(); - rsp->gp_state = GP_PASSED; - wake_up_all(&rsp->gp_wait); - } else if (need_wait) { - wait_event(rsp->gp_wait, rsp->gp_state == GP_PASSED); - } else { - /* - * Possible when there's a pending CB from a rcu_sync_exit(). - * Nobody has yet been allowed the 'fast' path and thus we can - * avoid doing any sync(). The callback will get 'dropped'. - */ - WARN_ON_ONCE(rsp->gp_state != GP_PASSED); - } +static void rcu_sync_call(struct rcu_sync *rsp) +{ + call_rcu(&rsp->cb_head, rcu_sync_func); } /** * rcu_sync_func() - Callback function managing reader access to fastpath * @rhp: Pointer to rcu_head in rcu_sync structure to use for synchronization * - * This function is passed to one of the call_rcu() functions by + * This function is passed to call_rcu() function by rcu_sync_enter() and * rcu_sync_exit(), so that it is invoked after a grace period following the - * that invocation of rcu_sync_exit(). It takes action based on events that + * that invocation of enter/exit. + * + * If it is called by rcu_sync_enter() it signals that all the readers were + * switched onto slow path. + * + * If it is called by rcu_sync_exit() it takes action based on events that * have taken place in the meantime, so that closely spaced rcu_sync_enter() * and rcu_sync_exit() pairs need not wait for a grace period. * @@ -152,35 +75,88 @@ static void rcu_sync_func(struct rcu_head *rhp) struct rcu_sync *rsp = container_of(rhp, struct rcu_sync, cb_head); unsigned long flags; - WARN_ON_ONCE(rsp->gp_state != GP_PASSED); - WARN_ON_ONCE(rsp->cb_state == CB_IDLE); + WARN_ON_ONCE(READ_ONCE(rsp->gp_state) == GP_IDLE); + WARN_ON_ONCE(READ_ONCE(rsp->gp_state) == GP_PASSED); spin_lock_irqsave(&rsp->rss_lock, flags); if (rsp->gp_count) { /* - * A new rcu_sync_begin() has happened; drop the callback. + * We're at least a GP after the GP_IDLE->GP_ENTER transition. */ - rsp->cb_state = CB_IDLE; - } else if (rsp->cb_state == CB_REPLAY) { + WRITE_ONCE(rsp->gp_state, GP_PASSED); + wake_up_locked(&rsp->gp_wait); + } else if (rsp->gp_state == GP_REPLAY) { /* - * A new rcu_sync_exit() has happened; requeue the callback - * to catch a later GP. + * A new rcu_sync_exit() has happened; requeue the callback to + * catch a later GP. */ - rsp->cb_state = CB_PENDING; - gp_ops[rsp->gp_type].call(&rsp->cb_head, rcu_sync_func); + WRITE_ONCE(rsp->gp_state, GP_EXIT); + rcu_sync_call(rsp); } else { /* - * We're at least a GP after rcu_sync_exit(); eveybody will now - * have observed the write side critical section. Let 'em rip!. + * We're at least a GP after the last rcu_sync_exit(); eveybody + * will now have observed the write side critical section. + * Let 'em rip!. */ - rsp->cb_state = CB_IDLE; - rsp->gp_state = GP_IDLE; + WRITE_ONCE(rsp->gp_state, GP_IDLE); } spin_unlock_irqrestore(&rsp->rss_lock, flags); } /** - * rcu_sync_exit() - Allow readers back onto fast patch after grace period + * rcu_sync_enter() - Force readers onto slowpath + * @rsp: Pointer to rcu_sync structure to use for synchronization + * + * This function is used by updaters who need readers to make use of + * a slowpath during the update. After this function returns, all + * subsequent calls to rcu_sync_is_idle() will return false, which + * tells readers to stay off their fastpaths. A later call to + * rcu_sync_exit() re-enables reader slowpaths. + * + * When called in isolation, rcu_sync_enter() must wait for a grace + * period, however, closely spaced calls to rcu_sync_enter() can + * optimize away the grace-period wait via a state machine implemented + * by rcu_sync_enter(), rcu_sync_exit(), and rcu_sync_func(). + */ +void rcu_sync_enter(struct rcu_sync *rsp) +{ + int gp_state; + + spin_lock_irq(&rsp->rss_lock); + gp_state = rsp->gp_state; + if (gp_state == GP_IDLE) { + WRITE_ONCE(rsp->gp_state, GP_ENTER); + WARN_ON_ONCE(rsp->gp_count); + /* + * Note that we could simply do rcu_sync_call(rsp) here and + * avoid the "if (gp_state == GP_IDLE)" block below. + * + * However, synchronize_rcu() can be faster if rcu_expedited + * or rcu_blocking_is_gp() is true. + * + * Another reason is that we can't wait for rcu callback if + * we are called at early boot time but this shouldn't happen. + */ + } + rsp->gp_count++; + spin_unlock_irq(&rsp->rss_lock); + + if (gp_state == GP_IDLE) { + /* + * See the comment above, this simply does the "synchronous" + * call_rcu(rcu_sync_func) which does GP_ENTER -> GP_PASSED. + */ + synchronize_rcu(); + rcu_sync_func(&rsp->cb_head); + /* Not really needed, wait_event() would see GP_PASSED. */ + return; + } + + wait_event(rsp->gp_wait, READ_ONCE(rsp->gp_state) >= GP_PASSED); +} + +/** + * rcu_sync_exit() - Allow readers back onto fast path after grace period * @rsp: Pointer to rcu_sync structure to use for synchronization * * This function is used by updaters who have completed, and can therefore @@ -191,13 +167,16 @@ static void rcu_sync_func(struct rcu_head *rhp) */ void rcu_sync_exit(struct rcu_sync *rsp) { + WARN_ON_ONCE(READ_ONCE(rsp->gp_state) == GP_IDLE); + WARN_ON_ONCE(READ_ONCE(rsp->gp_count) == 0); + spin_lock_irq(&rsp->rss_lock); if (!--rsp->gp_count) { - if (rsp->cb_state == CB_IDLE) { - rsp->cb_state = CB_PENDING; - gp_ops[rsp->gp_type].call(&rsp->cb_head, rcu_sync_func); - } else if (rsp->cb_state == CB_PENDING) { - rsp->cb_state = CB_REPLAY; + if (rsp->gp_state == GP_PASSED) { + WRITE_ONCE(rsp->gp_state, GP_EXIT); + rcu_sync_call(rsp); + } else if (rsp->gp_state == GP_EXIT) { + WRITE_ONCE(rsp->gp_state, GP_REPLAY); } } spin_unlock_irq(&rsp->rss_lock); @@ -209,18 +188,19 @@ void rcu_sync_exit(struct rcu_sync *rsp) */ void rcu_sync_dtor(struct rcu_sync *rsp) { - int cb_state; + int gp_state; - WARN_ON_ONCE(rsp->gp_count); + WARN_ON_ONCE(READ_ONCE(rsp->gp_count)); + WARN_ON_ONCE(READ_ONCE(rsp->gp_state) == GP_PASSED); spin_lock_irq(&rsp->rss_lock); - if (rsp->cb_state == CB_REPLAY) - rsp->cb_state = CB_PENDING; - cb_state = rsp->cb_state; + if (rsp->gp_state == GP_REPLAY) + WRITE_ONCE(rsp->gp_state, GP_EXIT); + gp_state = rsp->gp_state; spin_unlock_irq(&rsp->rss_lock); - if (cb_state != CB_IDLE) { - gp_ops[rsp->gp_type].wait(); - WARN_ON_ONCE(rsp->cb_state != CB_IDLE); + if (gp_state != GP_IDLE) { + rcu_barrier(); + WARN_ON_ONCE(rsp->gp_state != GP_IDLE); } } diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index b9629cf08f94..a14e5fbbea46 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -401,7 +401,8 @@ static int rcu_is_cpu_rrupt_from_idle(void) return __this_cpu_read(rcu_data.dynticks_nesting) == 0; } -#define DEFAULT_RCU_BLIMIT 10 /* Maximum callbacks per rcu_do_batch. */ +#define DEFAULT_RCU_BLIMIT 10 /* Maximum callbacks per rcu_do_batch ... */ +#define DEFAULT_MAX_RCU_BLIMIT 10000 /* ... even during callback flood. */ static long blimit = DEFAULT_RCU_BLIMIT; #define DEFAULT_RCU_QHIMARK 10000 /* If this many pending, ignore blimit. */ static long qhimark = DEFAULT_RCU_QHIMARK; @@ -2134,7 +2135,7 @@ static void rcu_do_batch(struct rcu_data *rdp) /* Reinstate batch limit if we have worked down the excess. */ count = rcu_segcblist_n_cbs(&rdp->cblist); - if (rdp->blimit == LONG_MAX && count <= qlowmark) + if (rdp->blimit >= DEFAULT_MAX_RCU_BLIMIT && count <= qlowmark) rdp->blimit = blimit; /* Reset ->qlen_last_fqs_check trigger if enough CBs have drained. */ @@ -2464,7 +2465,7 @@ static void __call_rcu_core(struct rcu_data *rdp, struct rcu_head *head, rcu_accelerate_cbs_unlocked(rdp->mynode, rdp); } else { /* Give the grace period a kick. */ - rdp->blimit = LONG_MAX; + rdp->blimit = DEFAULT_MAX_RCU_BLIMIT; if (rcu_state.n_force_qs == rdp->n_force_qs_snap && rcu_segcblist_first_pend_cb(&rdp->cblist) != head) rcu_force_quiescent_state(); diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 8e539710721a..af7e7b9c86af 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -259,8 +259,7 @@ static bool sync_exp_work_done(unsigned long s) { if (rcu_exp_gp_seq_done(s)) { trace_rcu_exp_grace_period(rcu_state.name, s, TPS("done")); - /* Ensure test happens before caller kfree(). */ - smp_mb__before_atomic(); /* ^^^ */ + smp_mb(); /* Ensure test happens before caller kfree(). */ return true; } return false; diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 1aeb4ae187ce..acb225023ed1 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -777,7 +777,7 @@ dump_blkd_tasks(struct rcu_node *rnp, int ncheck) i = 0; list_for_each(lhp, &rnp->blkd_tasks) { pr_cont(" %p", lhp); - if (++i >= 10) + if (++i >= ncheck) break; } pr_cont("\n"); diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index f65a73a97323..065183391f75 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -630,7 +630,9 @@ static void rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp, time_before(j, rcu_state.gp_req_activity + gpssdelay) || time_before(j, rcu_state.gp_activity + gpssdelay) || atomic_xchg(&warned, 1)) { - raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */ + if (rnp_root != rnp) + /* irqs remain disabled. */ + raw_spin_unlock_rcu_node(rnp_root); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; } diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index c3bf44ba42e5..61df2bf08563 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -423,6 +423,19 @@ EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read); do { } while (0) #endif +#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST) +/* Get rcutorture access to sched_setaffinity(). */ +long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask) +{ + int ret; + + ret = sched_setaffinity(pid, in_mask); + WARN_ONCE(ret, "%s: sched_setaffinity() returned %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(rcutorture_sched_setaffinity); +#endif + #ifdef CONFIG_RCU_STALL_COMMON int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress); diff --git a/kernel/torture.c b/kernel/torture.c index 17b2be9bde12..a8d9bdfba7c3 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -570,6 +570,7 @@ static void torture_shutdown_cleanup(void) static struct task_struct *stutter_task; static int stutter_pause_test; static int stutter; +static int stutter_gap; /* * Block until the stutter interval ends. This must be called periodically @@ -578,10 +579,12 @@ static int stutter; bool stutter_wait(const char *title) { int spt; + bool ret = false; cond_resched_tasks_rcu_qs(); spt = READ_ONCE(stutter_pause_test); for (; spt; spt = READ_ONCE(stutter_pause_test)) { + ret = true; if (spt == 1) { schedule_timeout_interruptible(1); } else if (spt == 2) { @@ -592,7 +595,7 @@ bool stutter_wait(const char *title) } torture_shutdown_absorb(title); } - return !!spt; + return ret; } EXPORT_SYMBOL_GPL(stutter_wait); @@ -602,17 +605,24 @@ EXPORT_SYMBOL_GPL(stutter_wait); */ static int torture_stutter(void *arg) { + int wtime; + VERBOSE_TOROUT_STRING("torture_stutter task started"); do { if (!torture_must_stop() && stutter > 1) { - WRITE_ONCE(stutter_pause_test, 1); - schedule_timeout_interruptible(stutter - 1); + wtime = stutter; + if (stutter > HZ + 1) { + WRITE_ONCE(stutter_pause_test, 1); + wtime = stutter - HZ - 1; + schedule_timeout_interruptible(wtime); + wtime = HZ + 1; + } WRITE_ONCE(stutter_pause_test, 2); - schedule_timeout_interruptible(1); + schedule_timeout_interruptible(wtime); } WRITE_ONCE(stutter_pause_test, 0); if (!torture_must_stop()) - schedule_timeout_interruptible(stutter); + schedule_timeout_interruptible(stutter_gap); torture_shutdown_absorb("torture_stutter"); } while (!torture_must_stop()); torture_kthread_stopping("torture_stutter"); @@ -622,9 +632,10 @@ static int torture_stutter(void *arg) /* * Initialize and kick off the torture_stutter kthread. */ -int torture_stutter_init(const int s) +int torture_stutter_init(const int s, const int sgap) { stutter = s; + stutter_gap = sgap; return torture_create_kthread(torture_stutter, NULL, stutter_task); } EXPORT_SYMBOL_GPL(torture_stutter_init); diff --git a/tools/include/linux/rcu.h b/tools/include/linux/rcu.h index 7d02527e5bce..9554d3fa54f3 100644 --- a/tools/include/linux/rcu.h +++ b/tools/include/linux/rcu.h @@ -19,7 +19,7 @@ static inline bool rcu_is_watching(void) return false; } -#define rcu_assign_pointer(p, v) ((p) = (v)) -#define RCU_INIT_POINTER(p, v) p=(v) +#define rcu_assign_pointer(p, v) do { (p) = (v); } while (0) +#define RCU_INIT_POINTER(p, v) do { (p) = (v); } while (0) #endif diff --git a/tools/testing/radix-tree/linux/rcupdate.h b/tools/testing/radix-tree/linux/rcupdate.h index fd280b070fdb..fed468fb0c78 100644 --- a/tools/testing/radix-tree/linux/rcupdate.h +++ b/tools/testing/radix-tree/linux/rcupdate.h @@ -7,6 +7,6 @@ #define rcu_dereference_raw(p) rcu_dereference(p) #define rcu_dereference_protected(p, cond) rcu_dereference(p) #define rcu_dereference_check(p, cond) rcu_dereference(p) -#define RCU_INIT_POINTER(p, v) (p) = (v) +#define RCU_INIT_POINTER(p, v) do { (p) = (v); } while (0) #endif diff --git a/tools/testing/selftests/rcutorture/Makefile b/tools/testing/selftests/rcutorture/Makefile new file mode 100644 index 000000000000..5202dc666206 --- /dev/null +++ b/tools/testing/selftests/rcutorture/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0+ +all: + ( cd ../../../..; tools/testing/selftests/rcutorture/bin/kvm.sh --duration 10 --configs TREE01 ) diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh index 40359486b3a8..93e80a42249a 100755 --- a/tools/testing/selftests/rcutorture/bin/configinit.sh +++ b/tools/testing/selftests/rcutorture/bin/configinit.sh @@ -1,7 +1,7 @@ #!/bin/bash # SPDX-License-Identifier: GPL-2.0+ # -# Usage: configinit.sh config-spec-file build-output-dir results-dir +# Usage: configinit.sh config-spec-file results-dir # # Create a .config file from the spec file. Run from the kernel source tree. # Exits with 0 if all went well, with 1 if all went well but the config @@ -11,10 +11,6 @@ # desired settings, for example, "CONFIG_NO_HZ=y". For best results, # this should be a full pathname. # -# The second argument is a optional path to a build output directory, -# for example, "O=/tmp/foo". If this argument is omitted, the .config -# file will be generated directly in the current directory. -# # Copyright (C) IBM Corporation, 2013 # # Authors: Paul E. McKenney <paulmck@linux.ibm.com> @@ -26,34 +22,23 @@ mkdir $T # Capture config spec file. c=$1 -buildloc=$2 -resdir=$3 -builddir= -if echo $buildloc | grep -q '^O=' -then - builddir=`echo $buildloc | sed -e 's/^O=//'` - if test ! -d $builddir - then - mkdir $builddir - fi -else - echo Bad build directory: \"$buildloc\" - exit 2 -fi +resdir=$2 sed -e 's/^\(CONFIG[0-9A-Z_]*\)=.*$/grep -v "^# \1" |/' < $c > $T/u.sh sed -e 's/^\(CONFIG[0-9A-Z_]*=\).*$/grep -v \1 |/' < $c >> $T/u.sh grep '^grep' < $T/u.sh > $T/upd.sh echo "cat - $c" >> $T/upd.sh -make mrproper -make $buildloc distclean > $resdir/Make.distclean 2>&1 -make $buildloc $TORTURE_DEFCONFIG > $resdir/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 > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err +if test -z "$TORTURE_TRUST_MAKE" +then + make clean > $resdir/Make.clean 2>&1 +fi +make $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1 +mv .config .config.sav +sh $T/upd.sh < .config.sav > .config +cp .config .config.new +yes '' | make oldconfig > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err # verify new config matches specification. -configcheck.sh $builddir/.config $c +configcheck.sh .config $c exit 0 diff --git a/tools/testing/selftests/rcutorture/bin/cpus2use.sh b/tools/testing/selftests/rcutorture/bin/cpus2use.sh index ff7102212703..4e9485590c10 100755 --- a/tools/testing/selftests/rcutorture/bin/cpus2use.sh +++ b/tools/testing/selftests/rcutorture/bin/cpus2use.sh @@ -9,6 +9,11 @@ # # Authors: Paul E. McKenney <paulmck@linux.ibm.com> +if test -n "$TORTURE_ALLOTED_CPUS" +then + echo $TORTURE_ALLOTED_CPUS + exit 0 +fi ncpus=`grep '^processor' /proc/cpuinfo | wc -l` idlecpus=`mpstat | tail -1 | \ awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'` diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh index 6bcb8b5b2ff2..c3a49fb4d6f6 100644 --- a/tools/testing/selftests/rcutorture/bin/functions.sh +++ b/tools/testing/selftests/rcutorture/bin/functions.sh @@ -172,7 +172,7 @@ identify_qemu_append () { local console=ttyS0 case "$1" in qemu-system-x86_64|qemu-system-i386) - echo noapic selinux=0 initcall_debug debug + echo selinux=0 initcall_debug debug ;; qemu-system-aarch64) console=ttyAMA0 @@ -191,8 +191,19 @@ identify_qemu_append () { # Output arguments for qemu arguments based on the TORTURE_QEMU_MAC # and TORTURE_QEMU_INTERACTIVE environment variables. identify_qemu_args () { + local KVM_CPU="" + case "$1" in + qemu-system-x86_64) + KVM_CPU=kvm64 + ;; + qemu-system-i386) + KVM_CPU=kvm32 + ;; + esac case "$1" in qemu-system-x86_64|qemu-system-i386) + echo -machine q35,accel=kvm + echo -cpu ${KVM_CPU} ;; qemu-system-aarch64) echo -machine virt,gic-version=host -cpu host diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh index 435b60933985..dc49a3ba6111 100755 --- a/tools/testing/selftests/rcutorture/bin/jitter.sh +++ b/tools/testing/selftests/rcutorture/bin/jitter.sh @@ -34,10 +34,15 @@ do exit 0; fi - # Set affinity to randomly selected CPU - cpus=`ls /sys/devices/system/cpu/*/online | - sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' | - grep -v '^0*$'` + # Set affinity to randomly selected online CPU + cpus=`grep 1 /sys/devices/system/cpu/*/online | + sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//'` + + # Do not leave out poor old cpu0 which may not be hot-pluggable + if [ ! -f "/sys/devices/system/cpu/cpu0/online" ]; then + cpus="0 $cpus" + fi + cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN { srand(n + me + systime()); ncpus = split(cpus, ca); diff --git a/tools/testing/selftests/rcutorture/bin/kvm-build.sh b/tools/testing/selftests/rcutorture/bin/kvm-build.sh index c27a0bbb9c02..18d6518504ee 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-build.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-build.sh @@ -3,7 +3,7 @@ # # Build a kvm-ready Linux kernel from the tree in the current directory. # -# Usage: kvm-build.sh config-template build-dir resdir +# Usage: kvm-build.sh config-template resdir # # Copyright (C) IBM Corporation, 2011 # @@ -15,8 +15,7 @@ then echo "kvm-build.sh :$config_template: Not a readable file" exit 1 fi -builddir=${2} -resdir=${3} +resdir=${2} T=${TMPDIR-/tmp}/test-linux.sh.$$ trap 'rm -rf $T' 0 @@ -29,14 +28,14 @@ CONFIG_VIRTIO_PCI=y CONFIG_VIRTIO_CONSOLE=y ___EOF___ -configinit.sh $T/config O=$builddir $resdir +configinit.sh $T/config $resdir retval=$? if test $retval -gt 1 then exit 2 fi ncpus=`cpus2use.sh` -make O=$builddir -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1 +make -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1 retval=$? if test $retval -ne 0 || grep "rcu[^/]*": < $resdir/Make.out | egrep -q "Stop|Error|error:|warning:" || egrep -q "Stop|Error|error:" < $resdir/Make.out then diff --git a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh index 8426fe1f15ee..1871d00bccd7 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh @@ -11,6 +11,7 @@ # # The "directory" above should end with the date/time directory, for example, # "tools/testing/selftests/rcutorture/res/2018.02.25-14:27:27". +# Returns error status reflecting the success (or not) of the specified run. # # Copyright (C) IBM Corporation, 2018 # @@ -56,6 +57,8 @@ done if test -n "$files" then $editor $files + exit 1 else echo No errors in console logs. + exit 0 fi diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh index 2adde6aaafdb..e5edd5198725 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh @@ -7,6 +7,8 @@ # # Usage: kvm-recheck.sh resdir ... # +# Returns status reflecting the success or not of the last run specified. +# # Copyright (C) IBM Corporation, 2011 # # Authors: Paul E. McKenney <paulmck@linux.ibm.com> @@ -28,8 +30,16 @@ do TORTURE_SUITE="`cat $i/../TORTURE_SUITE`" rm -f $i/console.log.*.diags kvm-recheck-${TORTURE_SUITE}.sh $i - if test -f "$i/console.log" + if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -ne 0 && test "`cat $i/qemu-retval`" -ne 137 + then + echo QEMU error, output: + cat $i/qemu-output + elif test -f "$i/console.log" then + if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -eq 137 + then + echo QEMU killed + fi configcheck.sh $i/.config $i/ConfigFragment if test -r $i/Make.oldconfig.err then @@ -58,3 +68,4 @@ do fi done done +EDITOR=echo kvm-find-errors.sh "${@: -1}" > /dev/null 2>&1 diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh index 0eb1ec16d78a..27b7b5693ede 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh @@ -36,11 +36,6 @@ config_template=${1} config_dir=`echo $config_template | sed -e 's,/[^/]*$,,'` title=`echo $config_template | sed -e 's/^.*\///'` builddir=${2} -if test -z "$builddir" -o ! -d "$builddir" -o ! -w "$builddir" -then - echo "kvm-test-1-run.sh :$builddir: Not a writable directory, cannot build into it" - exit 1 -fi resdir=${3} if test -z "$resdir" -o ! -d "$resdir" -o ! -w "$resdir" then @@ -85,18 +80,18 @@ then ln -s $base_resdir/.config $resdir # for kvm-recheck.sh # Arch-independent indicator touch $resdir/builtkernel -elif kvm-build.sh $T/Kc2 $builddir $resdir +elif kvm-build.sh $T/Kc2 $resdir then # Had to build a kernel for this test. - QEMU="`identify_qemu $builddir/vmlinux`" + QEMU="`identify_qemu vmlinux`" BOOT_IMAGE="`identify_boot_image $QEMU`" - cp $builddir/vmlinux $resdir - cp $builddir/.config $resdir - cp $builddir/Module.symvers $resdir > /dev/null || : - cp $builddir/System.map $resdir > /dev/null || : + cp vmlinux $resdir + cp .config $resdir + cp Module.symvers $resdir > /dev/null || : + cp System.map $resdir > /dev/null || : if test -n "$BOOT_IMAGE" then - cp $builddir/$BOOT_IMAGE $resdir + cp $BOOT_IMAGE $resdir KERNEL=$resdir/${BOOT_IMAGE##*/} # Arch-independent indicator touch $resdir/builtkernel @@ -107,7 +102,7 @@ then parse-build.sh $resdir/Make.out $title else # Build failed. - cp $builddir/.config $resdir || : + cp .config $resdir || : echo Build failed, not running KVM, see $resdir. if test -f $builddir.wait then @@ -165,7 +160,7 @@ then fi echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd -( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append "$qemu_append $boot_args"& echo $! > $resdir/qemu_pid; wait `cat $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) & +( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append "$qemu_append $boot_args" > $resdir/qemu-output 2>&1 & echo $! > $resdir/qemu_pid; wait `cat $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) & commandcompleted=0 sleep 10 # Give qemu's pid a chance to reach the file if test -s "$resdir/qemu_pid" diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh index 8f1e337b9b54..72518580df23 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm.sh @@ -24,6 +24,7 @@ dur=$((30*60)) dryrun="" KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM PATH=${KVM}/bin:$PATH; export PATH +TORTURE_ALLOTED_CPUS="" TORTURE_DEFCONFIG=defconfig TORTURE_BOOT_IMAGE="" TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD @@ -32,6 +33,7 @@ TORTURE_KMAKE_ARG="" TORTURE_QEMU_MEM=512 TORTURE_SHUTDOWN_GRACE=180 TORTURE_SUITE=rcu +TORTURE_TRUST_MAKE="" resdir="" configs="" cpus=0 @@ -62,6 +64,7 @@ usage () { echo " --qemu-cmd qemu-system-..." echo " --results absolute-pathname" echo " --torture rcu" + echo " --trust-make" exit 1 } @@ -89,6 +92,7 @@ do --cpus) checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--' cpus=$2 + TORTURE_ALLOTED_CPUS="$2" shift ;; --datestamp) @@ -173,6 +177,9 @@ do jitter=0 fi ;; + --trust-make) + TORTURE_TRUST_MAKE="y" + ;; *) echo Unknown argument $1 usage @@ -285,6 +292,7 @@ cat << ___EOF___ > $T/script CONFIGFRAG="$CONFIGFRAG"; export CONFIGFRAG KVM="$KVM"; export KVM PATH="$PATH"; export PATH +TORTURE_ALLOTED_CPUS="$TORTURE_ALLOTED_CPUS"; export TORTURE_ALLOTED_CPUS TORTURE_BOOT_IMAGE="$TORTURE_BOOT_IMAGE"; export TORTURE_BOOT_IMAGE TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG @@ -297,6 +305,7 @@ TORTURE_QEMU_MAC="$TORTURE_QEMU_MAC"; export TORTURE_QEMU_MAC TORTURE_QEMU_MEM="$TORTURE_QEMU_MEM"; export TORTURE_QEMU_MEM TORTURE_SHUTDOWN_GRACE="$TORTURE_SHUTDOWN_GRACE"; export TORTURE_SHUTDOWN_GRACE TORTURE_SUITE="$TORTURE_SUITE"; export TORTURE_SUITE +TORTURE_TRUST_MAKE="$TORTURE_TRUST_MAKE"; export TORTURE_TRUST_MAKE if ! test -e $resdir then mkdir -p "$resdir" || : @@ -342,7 +351,7 @@ function dump(first, pastlast, batchnum) print "needqemurun=" jn=1 for (j = first; j < pastlast; j++) { - builddir=KVM "/b1" + builddir=KVM "/b" j - first + 1 cpusr[jn] = cpus[j]; if (cfrep[cf[j]] == "") { cfr[jn] = cf[j]; @@ -358,7 +367,6 @@ function dump(first, pastlast, batchnum) print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` | tee -a " rd "log"; print "rm -f " builddir ".*"; print "touch " builddir ".wait"; - print "mkdir " builddir " > /dev/null 2>&1 || :"; print "mkdir " rd cfr[jn] " || :"; print "kvm-test-1-run.sh " CONFIGDIR cf[j], builddir, rd cfr[jn], dur " \"" TORTURE_QEMU_ARG "\" \"" TORTURE_BOOTARGS "\" > " rd cfr[jn] "/kvm-test-1-run.sh.out 2>&1 &" print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` | tee -a " rd "log"; @@ -464,3 +472,5 @@ else fi # Tracing: trace_event=rcu:rcu_grace_period,rcu:rcu_future_grace_period,rcu:rcu_grace_period_init,rcu:rcu_nocb_wake,rcu:rcu_preempt_task,rcu:rcu_unlock_preempted_task,rcu:rcu_quiescent_state_report,rcu:rcu_fqs,rcu:rcu_callback,rcu:rcu_kfree_callback,rcu:rcu_batch_start,rcu:rcu_invoke_callback,rcu:rcu_invoke_kfree_callback,rcu:rcu_batch_end,rcu:rcu_torture_read,rcu:rcu_barrier +# Function-graph tracing: ftrace=function_graph ftrace_graph_filter=sched_setaffinity,migration_cpu_stop +# Also --kconfig "CONFIG_FUNCTION_TRACER=y CONFIG_FUNCTION_GRAPH_TRACER=y" diff --git a/tools/testing/selftests/rcutorture/bin/parse-build.sh b/tools/testing/selftests/rcutorture/bin/parse-build.sh index 0701b3bf6ade..09155c15ea65 100755 --- a/tools/testing/selftests/rcutorture/bin/parse-build.sh +++ b/tools/testing/selftests/rcutorture/bin/parse-build.sh @@ -21,7 +21,7 @@ mkdir $T . functions.sh -if grep -q CC < $F +if grep -q CC < $F || test -n "$TORTURE_TRUST_MAKE" then : else diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh index 4508373a922f..4bf62d7b1cbc 100755 --- a/tools/testing/selftests/rcutorture/bin/parse-console.sh +++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh @@ -106,6 +106,7 @@ fi | tee -a $file.diags egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for' < $file | grep -v 'ODEBUG: ' | +grep -v 'This means that this is a DEBUG kernel and it is' | grep -v 'Warning: unable to open an initial console' > $T.diags if test -s $T.diags then diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon index d2d2a86139db..e19a444a0684 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon +++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon @@ -1,2 +1,5 @@ CONFIG_RCU_TORTURE_TEST=y CONFIG_PRINTK_TIME=y +CONFIG_HYPERVISOR_GUEST=y +CONFIG_PARAVIRT=y +CONFIG_KVM_GUEST=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot index ea47da95374b..d6da9a61d44a 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot @@ -3,3 +3,4 @@ rcutree.gp_preinit_delay=3 rcutree.gp_init_delay=3 rcutree.gp_cleanup_delay=3 rcu_nocbs=0 +rcutorture.fwd_progress=0 diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL new file mode 100644 index 000000000000..4d8eb5bfb6f6 --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL @@ -0,0 +1,14 @@ +CONFIG_SMP=y +CONFIG_NR_CPUS=8 +CONFIG_PREEMPT_NONE=y +CONFIG_PREEMPT_VOLUNTARY=n +CONFIG_PREEMPT=n +CONFIG_HZ_PERIODIC=n +CONFIG_NO_HZ_IDLE=y +CONFIG_NO_HZ_FULL=n +CONFIG_HOTPLUG_CPU=n +CONFIG_SUSPEND=n +CONFIG_HIBERNATION=n +CONFIG_DEBUG_LOCK_ALLOC=n +CONFIG_DEBUG_OBJECTS_RCU_HEAD=n +CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot new file mode 100644 index 000000000000..7017f5f5a55f --- /dev/null +++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot @@ -0,0 +1,3 @@ +rcutorture.torture_type=trivial +rcutorture.onoff_interval=0 +rcutorture.shuffle_interval=0 |