diff options
24 files changed, 308 insertions, 191 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bdc1f33fd3d1..6d984f153669 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4269,6 +4269,18 @@ are zero, rcutorture acts as if is interpreted they are all non-zero. + rcutorture.irqreader= [KNL] + Run RCU readers from irq handlers, or, more + accurately, from a timer handler. Not all RCU + flavors take kindly to this sort of thing. + + rcutorture.leakpointer= [KNL] + Leak an RCU-protected pointer out of the reader. + This can of course result in splats, and is + intended to test the ability of things like + CONFIG_RCU_STRICT_GRACE_PERIOD=y to detect + such leaks. + rcutorture.n_barrier_cbs= [KNL] Set callbacks/threads for rcu_barrier() testing. diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index a84a141a2ad2..8443a675715b 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -229,7 +229,8 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, return; idx = srcu_read_lock(&head->track_srcu); - hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) + hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, + srcu_read_lock_held(&head->track_srcu)) if (n->track_write) n->track_write(vcpu, gpa, new, bytes, n); srcu_read_unlock(&head->track_srcu, idx); @@ -254,7 +255,8 @@ void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot) return; idx = srcu_read_lock(&head->track_srcu); - hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) + hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, + srcu_read_lock_held(&head->track_srcu)) if (n->track_flush_slot) n->track_flush_slot(kvm, slot, n); srcu_read_unlock(&head->track_srcu, idx); diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 7a6fc9956510..f8633d37e358 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -63,9 +63,17 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list) RCU_LOCKDEP_WARN(!(cond) && !rcu_read_lock_any_held(), \ "RCU-list traversed in non-reader section!"); \ }) + +#define __list_check_srcu(cond) \ + ({ \ + RCU_LOCKDEP_WARN(!(cond), \ + "RCU-list traversed without holding the required lock!");\ + }) #else #define __list_check_rcu(dummy, cond, extra...) \ ({ check_arg_count_one(extra); }) + +#define __list_check_srcu(cond) ({ }) #endif /* @@ -386,6 +394,25 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, pos = list_entry_rcu(pos->member.next, typeof(*pos), member)) /** + * list_for_each_entry_srcu - iterate over rcu list of given type + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_head within the struct. + * @cond: lockdep expression for the lock required to traverse the list. + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as list_add_rcu() + * as long as the traversal is guarded by srcu_read_lock(). + * The lockdep expression srcu_read_lock_held() can be passed as the + * cond argument from read side. + */ +#define list_for_each_entry_srcu(pos, head, member, cond) \ + for (__list_check_srcu(cond), \ + pos = list_entry_rcu((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry_rcu(pos->member.next, typeof(*pos), member)) + +/** * list_entry_lockless - get the struct for this entry * @ptr: the &struct list_head pointer. * @type: the type of the struct this is embedded in. @@ -684,6 +711,27 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, &(pos)->member)), typeof(*(pos)), member)) /** + * hlist_for_each_entry_srcu - iterate over rcu list of given type + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + * @cond: lockdep expression for the lock required to traverse the list. + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as hlist_add_head_rcu() + * as long as the traversal is guarded by srcu_read_lock(). + * The lockdep expression srcu_read_lock_held() can be passed as the + * cond argument from read side. + */ +#define hlist_for_each_entry_srcu(pos, head, member, cond) \ + for (__list_check_srcu(cond), \ + pos = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),\ + typeof(*(pos)), member); \ + pos; \ + pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(\ + &(pos)->member)), typeof(*(pos)), member)) + +/** * hlist_for_each_entry_rcu_notrace - iterate over rcu list of given type (for tracing) * @pos: the type * to use as a loop cursor. * @head: the head for your list. diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index d15d46db61f7..b47d6b66665e 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -709,8 +709,8 @@ static inline void rcu_read_lock_bh(void) "rcu_read_lock_bh() used illegally while idle"); } -/* - * rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section +/** + * rcu_read_unlock_bh() - marks the end of a softirq-only RCU critical section * * See rcu_read_lock_bh() for more information. */ @@ -751,10 +751,10 @@ static inline notrace void rcu_read_lock_sched_notrace(void) __acquire(RCU_SCHED); } -/* - * rcu_read_unlock_sched - marks the end of a RCU-classic critical section +/** + * rcu_read_unlock_sched() - marks the end of a RCU-classic critical section * - * See rcu_read_lock_sched for more information. + * See rcu_read_lock_sched() for more information. */ static inline void rcu_read_unlock_sched(void) { @@ -945,7 +945,7 @@ static inline void rcu_head_init(struct rcu_head *rhp) } /** - * rcu_head_after_call_rcu - Has this rcu_head been passed to call_rcu()? + * rcu_head_after_call_rcu() - Has this rcu_head been passed to call_rcu()? * @rhp: The rcu_head structure to test. * @f: The function passed to call_rcu() along with @rhp. * diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 5cc9637cac16..7c1ecdb356d8 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -103,7 +103,6 @@ static inline void rcu_scheduler_starting(void) { } static inline void rcu_end_inkernel_boot(void) { } static inline bool rcu_inkernel_boot_has_ended(void) { return true; } static inline bool rcu_is_watching(void) { return true; } -static inline bool __rcu_is_watching(void) { return true; } static inline void rcu_momentary_dyntick_idle(void) { } static inline void kfree_rcu_scheduler_running(void) { } static inline bool rcu_gp_might_be_stalled(void) { return false; } diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index d2f4064ebd1d..59eb5cd567d7 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -64,7 +64,6 @@ extern int rcu_scheduler_active __read_mostly; void rcu_end_inkernel_boot(void); bool rcu_inkernel_boot_has_ended(void); bool rcu_is_watching(void); -bool __rcu_is_watching(void); #ifndef CONFIG_PREEMPTION void rcu_all_qs(void); #endif diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index ced71237b7e4..155b5cb43cfd 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -74,17 +74,17 @@ TRACE_EVENT_RCU(rcu_grace_period, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(const char *, gpevent) ), TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->gpevent = gpevent; ), - TP_printk("%s %lu %s", + TP_printk("%s %ld %s", __entry->rcuname, __entry->gp_seq, __entry->gpevent) ); @@ -114,8 +114,8 @@ TRACE_EVENT_RCU(rcu_future_grace_period, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) - __field(unsigned long, gp_seq_req) + __field(long, gp_seq) + __field(long, gp_seq_req) __field(u8, level) __field(int, grplo) __field(int, grphi) @@ -124,16 +124,16 @@ TRACE_EVENT_RCU(rcu_future_grace_period, TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; - __entry->gp_seq_req = gp_seq_req; + __entry->gp_seq = (long)gp_seq; + __entry->gp_seq_req = (long)gp_seq_req; __entry->level = level; __entry->grplo = grplo; __entry->grphi = grphi; __entry->gpevent = gpevent; ), - TP_printk("%s %lu %lu %u %d %d %s", - __entry->rcuname, __entry->gp_seq, __entry->gp_seq_req, __entry->level, + TP_printk("%s %ld %ld %u %d %d %s", + __entry->rcuname, (long)__entry->gp_seq, (long)__entry->gp_seq_req, __entry->level, __entry->grplo, __entry->grphi, __entry->gpevent) ); @@ -153,7 +153,7 @@ TRACE_EVENT_RCU(rcu_grace_period_init, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(u8, level) __field(int, grplo) __field(int, grphi) @@ -162,14 +162,14 @@ TRACE_EVENT_RCU(rcu_grace_period_init, TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->level = level; __entry->grplo = grplo; __entry->grphi = grphi; __entry->qsmask = qsmask; ), - TP_printk("%s %lu %u %d %d %lx", + TP_printk("%s %ld %u %d %d %lx", __entry->rcuname, __entry->gp_seq, __entry->level, __entry->grplo, __entry->grphi, __entry->qsmask) ); @@ -197,17 +197,17 @@ TRACE_EVENT_RCU(rcu_exp_grace_period, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gpseq) + __field(long, gpseq) __field(const char *, gpevent) ), TP_fast_assign( __entry->rcuname = rcuname; - __entry->gpseq = gpseq; + __entry->gpseq = (long)gpseq; __entry->gpevent = gpevent; ), - TP_printk("%s %lu %s", + TP_printk("%s %ld %s", __entry->rcuname, __entry->gpseq, __entry->gpevent) ); @@ -316,17 +316,17 @@ TRACE_EVENT_RCU(rcu_preempt_task, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(int, pid) ), TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->pid = pid; ), - TP_printk("%s %lu %d", + TP_printk("%s %ld %d", __entry->rcuname, __entry->gp_seq, __entry->pid) ); @@ -343,17 +343,17 @@ TRACE_EVENT_RCU(rcu_unlock_preempted_task, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(int, pid) ), TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->pid = pid; ), - TP_printk("%s %lu %d", __entry->rcuname, __entry->gp_seq, __entry->pid) + TP_printk("%s %ld %d", __entry->rcuname, __entry->gp_seq, __entry->pid) ); /* @@ -374,7 +374,7 @@ TRACE_EVENT_RCU(rcu_quiescent_state_report, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(unsigned long, mask) __field(unsigned long, qsmask) __field(u8, level) @@ -385,7 +385,7 @@ TRACE_EVENT_RCU(rcu_quiescent_state_report, TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->mask = mask; __entry->qsmask = qsmask; __entry->level = level; @@ -394,7 +394,7 @@ TRACE_EVENT_RCU(rcu_quiescent_state_report, __entry->gp_tasks = gp_tasks; ), - TP_printk("%s %lu %lx>%lx %u %d %d %u", + TP_printk("%s %ld %lx>%lx %u %d %d %u", __entry->rcuname, __entry->gp_seq, __entry->mask, __entry->qsmask, __entry->level, __entry->grplo, __entry->grphi, __entry->gp_tasks) @@ -415,19 +415,19 @@ TRACE_EVENT_RCU(rcu_fqs, TP_STRUCT__entry( __field(const char *, rcuname) - __field(unsigned long, gp_seq) + __field(long, gp_seq) __field(int, cpu) __field(const char *, qsevent) ), TP_fast_assign( __entry->rcuname = rcuname; - __entry->gp_seq = gp_seq; + __entry->gp_seq = (long)gp_seq; __entry->cpu = cpu; __entry->qsevent = qsevent; ), - TP_printk("%s %lu %d %s", + TP_printk("%s %ld %d %s", __entry->rcuname, __entry->gp_seq, __entry->cpu, __entry->qsevent) ); diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 9852e0d62d95..ad794a10fa80 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -278,7 +278,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) * terminate a grace period, if and only if the timer interrupt is * not nested into another interrupt. * - * Checking for __rcu_is_watching() here would prevent the nesting + * Checking for rcu_is_watching() here would prevent the nesting * interrupt to invoke rcu_irq_enter(). If that nested interrupt is * the tick then rcu_flavor_sched_clock_irq() would wrongfully * assume that it is the first interupt and eventually claim diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 9cfa5e89cff7..62d215b2e39f 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -566,7 +566,7 @@ static struct lock_torture_ops rwsem_lock_ops = { #include <linux/percpu-rwsem.h> static struct percpu_rw_semaphore pcpu_rwsem; -void torture_percpu_rwsem_init(void) +static void torture_percpu_rwsem_init(void) { BUG_ON(percpu_init_rwsem(&pcpu_rwsem)); } diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c index 9a0f66133b4b..2d2a6b6b9dfb 100644 --- a/kernel/rcu/rcu_segcblist.c +++ b/kernel/rcu/rcu_segcblist.c @@ -475,8 +475,16 @@ bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq) * Also advance to the oldest segment of callbacks whose * ->gp_seq[] completion is at or after that passed in via "seq", * skipping any empty segments. + * + * Note that segment "i" (and any lower-numbered segments + * containing older callbacks) will be unaffected, and their + * grace-period numbers remain unchanged. For example, if i == + * WAIT_TAIL, then neither WAIT_TAIL nor DONE_TAIL will be touched. + * Instead, the CBs in NEXT_TAIL will be merged with those in + * NEXT_READY_TAIL and the grace-period number of NEXT_READY_TAIL + * would be updated. NEXT_TAIL would then be empty. */ - if (++i >= RCU_NEXT_TAIL) + if (rcu_segcblist_restempty(rsclp, i) || ++i >= RCU_NEXT_TAIL) return false; /* diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index f453bf8d2f1e..916ea4f66e4b 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -52,19 +52,6 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); -#ifndef data_race -#define data_race(expr) \ - ({ \ - expr; \ - }) -#endif -#ifndef ASSERT_EXCLUSIVE_WRITER -#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0) -#endif -#ifndef ASSERT_EXCLUSIVE_ACCESS -#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0) -#endif - /* Bits for ->extendables field, extendables param, and related definitions. */ #define RCUTORTURE_RDR_SHIFT 8 /* Put SRCU index in upper bits. */ #define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1) @@ -100,6 +87,7 @@ torture_param(bool, gp_normal, false, "Use normal (non-expedited) GP wait primitives"); torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); +torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers"); torture_param(int, n_barrier_cbs, 0, "# of callbacks/kthreads for barrier testing"); torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); @@ -185,6 +173,7 @@ static long n_barrier_successes; /* did rcu_barrier test succeed? */ static unsigned long n_read_exits; static struct list_head rcu_torture_removed; static unsigned long shutdown_jiffies; +static unsigned long start_gp_seq; static int rcu_torture_writer_state; #define RTWS_FIXED_DELAY 0 @@ -1413,6 +1402,9 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp) preempt_enable(); rcutorture_one_extend(&readstate, 0, trsp, rtrsp); WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK); + // This next splat is expected behavior if leakpointer, especially + // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. + WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1); /* If error or close call, record the sequence of reader protections. */ if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { @@ -1808,6 +1800,7 @@ struct rcu_fwd { unsigned long rcu_launder_gp_seq_start; }; +static DEFINE_MUTEX(rcu_fwd_mutex); static struct rcu_fwd *rcu_fwds; static bool rcu_fwd_emergency_stop; @@ -2074,8 +2067,14 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) static int rcutorture_oom_notify(struct notifier_block *self, unsigned long notused, void *nfreed) { - struct rcu_fwd *rfp = rcu_fwds; + struct rcu_fwd *rfp; + mutex_lock(&rcu_fwd_mutex); + rfp = rcu_fwds; + if (!rfp) { + mutex_unlock(&rcu_fwd_mutex); + return NOTIFY_OK; + } WARN(1, "%s invoked upon OOM during forward-progress testing.\n", __func__); rcu_torture_fwd_cb_hist(rfp); @@ -2093,6 +2092,7 @@ static int rcutorture_oom_notify(struct notifier_block *self, smp_mb(); /* Frees before return to avoid redoing OOM. */ (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ pr_info("%s returning after OOM processing.\n", __func__); + mutex_unlock(&rcu_fwd_mutex); return NOTIFY_OK; } @@ -2114,13 +2114,11 @@ static int rcu_torture_fwd_prog(void *args) do { schedule_timeout_interruptible(fwd_progress_holdoff * HZ); WRITE_ONCE(rcu_fwd_emergency_stop, false); - register_oom_notifier(&rcutorture_oom_nb); if (!IS_ENABLED(CONFIG_TINY_RCU) || rcu_inkernel_boot_has_ended()) rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); if (rcu_inkernel_boot_has_ended()) rcu_torture_fwd_prog_cr(rfp); - unregister_oom_notifier(&rcutorture_oom_nb); /* Avoid slow periods, better to test when busy. */ stutter_wait("rcu_torture_fwd_prog"); @@ -2160,9 +2158,26 @@ static int __init rcu_torture_fwd_prog_init(void) return -ENOMEM; spin_lock_init(&rfp->rcu_fwd_lock); rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; + mutex_lock(&rcu_fwd_mutex); + rcu_fwds = rfp; + mutex_unlock(&rcu_fwd_mutex); + register_oom_notifier(&rcutorture_oom_nb); return torture_create_kthread(rcu_torture_fwd_prog, rfp, fwd_prog_task); } +static void rcu_torture_fwd_prog_cleanup(void) +{ + struct rcu_fwd *rfp; + + torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task); + rfp = rcu_fwds; + mutex_lock(&rcu_fwd_mutex); + rcu_fwds = NULL; + mutex_unlock(&rcu_fwd_mutex); + unregister_oom_notifier(&rcutorture_oom_nb); + kfree(rfp); +} + /* Callback function for RCU barrier testing. */ static void rcu_torture_barrier_cbf(struct rcu_head *rcu) { @@ -2460,7 +2475,7 @@ rcu_torture_cleanup(void) show_rcu_gp_kthreads(); rcu_torture_read_exit_cleanup(); rcu_torture_barrier_cleanup(); - torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task); + rcu_torture_fwd_prog_cleanup(); torture_stop_kthread(rcu_torture_stall, stall_task); torture_stop_kthread(rcu_torture_writer, writer_task); @@ -2482,8 +2497,9 @@ rcu_torture_cleanup(void) rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq); srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq); - pr_alert("%s: End-test grace-period state: g%lu f%#x\n", - cur_ops->name, gp_seq, flags); + pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n", + cur_ops->name, (long)gp_seq, flags, + rcutorture_seq_diff(gp_seq, start_gp_seq)); torture_stop_kthread(rcu_torture_stats, stats_task); torture_stop_kthread(rcu_torture_fqs, fqs_task); if (rcu_torture_can_boost()) @@ -2607,6 +2623,8 @@ rcu_torture_init(void) long i; int cpu; int firsterr = 0; + int flags = 0; + unsigned long gp_seq = 0; static struct rcu_torture_ops *torture_ops[] = { &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops, &tasks_ops, &tasks_rude_ops, @@ -2649,6 +2667,11 @@ rcu_torture_init(void) nrealreaders = 1; } rcu_torture_print_module_parms(cur_ops, "Start of test"); + rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq); + srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq); + start_gp_seq = gp_seq; + pr_alert("%s: Start-test grace-period state: g%ld f%#x\n", + cur_ops->name, (long)gp_seq, flags); /* Set up the freelist. */ diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index d9291f883b54..952595c678b3 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -546,9 +546,11 @@ static int main_func(void *arg) // Print the average of all experiments SCALEOUT("END OF TEST. Calculating average duration per loop (nanoseconds)...\n"); - buf[0] = 0; - strcat(buf, "\n"); - strcat(buf, "Runs\tTime(ns)\n"); + if (!errexit) { + buf[0] = 0; + strcat(buf, "\n"); + strcat(buf, "Runs\tTime(ns)\n"); + } for (exp = 0; exp < nruns; exp++) { u64 avg; diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index c100acf332ed..c13348ee80a5 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -29,19 +29,6 @@ #include "rcu.h" #include "rcu_segcblist.h" -#ifndef data_race -#define data_race(expr) \ - ({ \ - expr; \ - }) -#endif -#ifndef ASSERT_EXCLUSIVE_WRITER -#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0) -#endif -#ifndef ASSERT_EXCLUSIVE_ACCESS -#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0) -#endif - /* Holdoff in nanoseconds for auto-expediting. */ #define DEFAULT_SRCU_EXP_HOLDOFF (25 * 1000) static ulong exp_holdoff = DEFAULT_SRCU_EXP_HOLDOFF; diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8ce77d9ac716..92450642c4d8 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -70,19 +70,6 @@ #endif #define MODULE_PARAM_PREFIX "rcutree." -#ifndef data_race -#define data_race(expr) \ - ({ \ - expr; \ - }) -#endif -#ifndef ASSERT_EXCLUSIVE_WRITER -#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0) -#endif -#ifndef ASSERT_EXCLUSIVE_ACCESS -#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0) -#endif - /* Data structures. */ /* @@ -1090,11 +1077,6 @@ static void rcu_disable_urgency_upon_qs(struct rcu_data *rdp) } } -noinstr bool __rcu_is_watching(void) -{ - return !rcu_dynticks_curr_cpu_in_eqs(); -} - /** * rcu_is_watching - see if RCU thinks that the current CPU is not idle * @@ -1227,13 +1209,28 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) return 1; } - /* If waiting too long on an offline CPU, complain. */ - if (!(rdp->grpmask & rcu_rnp_online_cpus(rnp)) && - time_after(jiffies, rcu_state.gp_start + HZ)) { + /* + * Complain if a CPU that is considered to be offline from RCU's + * perspective has not yet reported a quiescent state. After all, + * the offline CPU should have reported a quiescent state during + * the CPU-offline process, or, failing that, by rcu_gp_init() + * if it ran concurrently with either the CPU going offline or the + * last task on a leaf rcu_node structure exiting its RCU read-side + * critical section while all CPUs corresponding to that structure + * are offline. This added warning detects bugs in any of these + * code paths. + * + * The rcu_node structure's ->lock is held here, which excludes + * the relevant portions the CPU-hotplug code, the grace-period + * initialization code, and the rcu_read_unlock() code paths. + * + * For more detail, please refer to the "Hotplug CPU" section + * of RCU's Requirements documentation. + */ + if (WARN_ON_ONCE(!(rdp->grpmask & rcu_rnp_online_cpus(rnp)))) { bool onl; struct rcu_node *rnp1; - WARN_ON(1); /* Offline CPUs are supposed to report QS! */ pr_info("%s: grp: %d-%d level: %d ->gp_seq %ld ->completedqs %ld\n", __func__, rnp->grplo, rnp->grphi, rnp->level, (long)rnp->gp_seq, (long)rnp->completedqs); @@ -1496,9 +1493,10 @@ static bool rcu_accelerate_cbs(struct rcu_node *rnp, struct rcu_data *rdp) /* Trace depending on how much we were able to accelerate. */ if (rcu_segcblist_restempty(&rdp->cblist, RCU_WAIT_TAIL)) - trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("AccWaitCB")); + trace_rcu_grace_period(rcu_state.name, gp_seq_req, TPS("AccWaitCB")); else - trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("AccReadyCB")); + trace_rcu_grace_period(rcu_state.name, gp_seq_req, TPS("AccReadyCB")); + return ret; } @@ -1718,10 +1716,13 @@ static bool rcu_gp_init(void) raw_spin_unlock_irq_rcu_node(rnp); /* - * Apply per-leaf buffered online and offline operations to the - * rcu_node tree. Note that this new grace period need not wait - * for subsequent online CPUs, and that quiescent-state forcing - * will handle subsequent offline CPUs. + * Apply per-leaf buffered online and offline operations to + * the rcu_node tree. Note that this new grace period need not + * wait for subsequent online CPUs, and that RCU hooks in the CPU + * offlining path, when combined with checks in this function, + * will handle CPUs that are currently going offline or that will + * go offline later. Please also refer to "Hotplug CPU" section + * of RCU's Requirements documentation. */ rcu_state.gp_state = RCU_GP_ONOFF; rcu_for_each_leaf_node(rnp) { @@ -1896,7 +1897,7 @@ static void rcu_gp_fqs_loop(void) break; /* If time for quiescent-state forcing, do it. */ if (!time_after(rcu_state.jiffies_force_qs, jiffies) || - (gf & RCU_GP_FLAG_FQS)) { + (gf & (RCU_GP_FLAG_FQS | RCU_GP_FLAG_OVLD))) { trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, TPS("fqsstart")); rcu_gp_fqs(first_gp_fqs); @@ -2374,6 +2375,7 @@ int rcutree_dead_cpu(unsigned int cpu) */ static void rcu_do_batch(struct rcu_data *rdp) { + int div; unsigned long flags; const bool offloaded = IS_ENABLED(CONFIG_RCU_NOCB_CPU) && rcu_segcblist_is_offloaded(&rdp->cblist); @@ -2402,9 +2404,15 @@ static void rcu_do_batch(struct rcu_data *rdp) rcu_nocb_lock(rdp); WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); pending = rcu_segcblist_n_cbs(&rdp->cblist); - bl = max(rdp->blimit, pending >> rcu_divisor); - if (unlikely(bl > 100)) - tlimit = local_clock() + rcu_resched_ns; + div = READ_ONCE(rcu_divisor); + div = div < 0 ? 7 : div > sizeof(long) * 8 - 2 ? sizeof(long) * 8 - 2 : div; + bl = max(rdp->blimit, pending >> div); + if (unlikely(bl > 100)) { + long rrn = READ_ONCE(rcu_resched_ns); + + rrn = rrn < NSEC_PER_MSEC ? NSEC_PER_MSEC : rrn > NSEC_PER_SEC ? NSEC_PER_SEC : rrn; + tlimit = local_clock() + rrn; + } trace_rcu_batch_start(rcu_state.name, rcu_segcblist_n_cbs(&rdp->cblist), bl); rcu_segcblist_extract_done_cbs(&rdp->cblist, &rcl); @@ -2545,8 +2553,7 @@ static void force_qs_rnp(int (*f)(struct rcu_data *rdp)) raw_spin_lock_irqsave_rcu_node(rnp, flags); rcu_state.cbovldnext |= !!rnp->cbovldmask; if (rnp->qsmask == 0) { - if (!IS_ENABLED(CONFIG_PREEMPT_RCU) || - rcu_preempt_blocked_readers_cgp(rnp)) { + if (rcu_preempt_blocked_readers_cgp(rnp)) { /* * No point in scanning bits because they * are all zero. But we might need to @@ -3443,7 +3450,7 @@ kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) unsigned long count = 0; /* Snapshot count of all CPUs */ - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); count += READ_ONCE(krcp->count); @@ -3458,7 +3465,7 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) int cpu, freed = 0; unsigned long flags; - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { int count; struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); @@ -3491,7 +3498,7 @@ void __init kfree_rcu_scheduler_running(void) int cpu; unsigned long flags; - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); raw_spin_lock_irqsave(&krcp->lock, flags); @@ -3973,8 +3980,6 @@ int rcutree_offline_cpu(unsigned int cpu) return 0; } -static DEFINE_PER_CPU(int, rcu_cpu_started); - /* * Mark the specified CPU as being online so that subsequent grace periods * (both expedited and normal) will wait on it. Note that this means that @@ -3994,12 +3999,11 @@ void rcu_cpu_starting(unsigned int cpu) struct rcu_node *rnp; bool newcpu; - if (per_cpu(rcu_cpu_started, cpu)) + rdp = per_cpu_ptr(&rcu_data, cpu); + if (rdp->cpu_started) return; + rdp->cpu_started = true; - per_cpu(rcu_cpu_started, cpu) = 1; - - rdp = per_cpu_ptr(&rcu_data, cpu); rnp = rdp->mynode; mask = rdp->grpmask; raw_spin_lock_irqsave_rcu_node(rnp, flags); @@ -4059,7 +4063,7 @@ void rcu_report_dead(unsigned int cpu) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); raw_spin_unlock(&rcu_state.ofl_lock); - per_cpu(rcu_cpu_started, cpu) = 0; + rdp->cpu_started = false; } /* diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index c96ae351688b..309bc7f41d35 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -156,6 +156,7 @@ struct rcu_data { bool beenonline; /* CPU online at least once. */ bool gpwrap; /* Possible ->gp_seq wrap. */ bool exp_deferred_qs; /* This CPU awaiting a deferred QS? */ + bool cpu_started; /* RCU watching this onlining CPU. */ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ unsigned long grpmask; /* Mask to apply to leaf qsmask. */ unsigned long ticks_this_gp; /* The number of scheduling-clock */ diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 1888c0eb1216..8760b6ead770 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -732,11 +732,9 @@ static void rcu_exp_need_qs(void) /* Invoked on each online non-idle CPU for expedited quiescent state. */ static void rcu_exp_handler(void *unused) { - struct rcu_data *rdp; - struct rcu_node *rnp; + struct rcu_data *rdp = this_cpu_ptr(&rcu_data); + struct rcu_node *rnp = rdp->mynode; - rdp = this_cpu_ptr(&rcu_data); - rnp = rdp->mynode; if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) || __this_cpu_read(rcu_data.cpu_no_qs.b.exp)) return; diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 982fc5be5269..cb1e8c8befb9 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1926,6 +1926,7 @@ static void nocb_gp_wait(struct rcu_data *my_rdp) * nearest grace period (if any) to wait for next. The CB kthreads * and the global grace-period kthread are awakened if needed. */ + WARN_ON_ONCE(my_rdp->nocb_gp_rdp != my_rdp); for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_cb_rdp) { trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Check")); rcu_nocb_lock_irqsave(rdp, flags); @@ -2411,13 +2412,12 @@ static void show_rcu_nocb_state(struct rcu_data *rdp) return; waslocked = raw_spin_is_locked(&rdp->nocb_gp_lock); - wastimer = timer_pending(&rdp->nocb_timer); + wastimer = timer_pending(&rdp->nocb_bypass_timer); wassleep = swait_active(&rdp->nocb_gp_wq); - if (!rdp->nocb_defer_wakeup && !rdp->nocb_gp_sleep && - !waslocked && !wastimer && !wassleep) + if (!rdp->nocb_gp_sleep && !waslocked && !wastimer && !wassleep) return; /* Nothing untowards. */ - pr_info(" !!! %c%c%c%c %c\n", + pr_info(" nocb GP activity on CB-only CPU!!! %c%c%c%c %c\n", "lL"[waslocked], "dD"[!!rdp->nocb_defer_wakeup], "tT"[wastimer], diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index b5d3b4794db4..0fde39b8daab 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -158,7 +158,7 @@ static void rcu_stall_kick_kthreads(void) { unsigned long j; - if (!rcu_kick_kthreads) + if (!READ_ONCE(rcu_kick_kthreads)) return; j = READ_ONCE(rcu_state.jiffies_kick_kthreads); if (time_after(jiffies, j) && rcu_state.gp_kthread && @@ -580,7 +580,7 @@ static void check_cpu_stall(struct rcu_data *rdp) unsigned long js; struct rcu_node *rnp; - if ((rcu_stall_is_suppressed() && !rcu_kick_kthreads) || + if ((rcu_stall_is_suppressed() && !READ_ONCE(rcu_kick_kthreads)) || !rcu_gp_in_progress()) return; rcu_stall_kick_kthreads(); @@ -623,7 +623,7 @@ static void check_cpu_stall(struct rcu_data *rdp) /* We haven't checked in, so go dump stack. */ print_cpu_stall(gps); - if (rcu_cpu_stall_ftrace_dump) + if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) rcu_ftrace_dump(DUMP_ALL); } else if (rcu_gp_in_progress() && @@ -632,7 +632,7 @@ static void check_cpu_stall(struct rcu_data *rdp) /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(gs2, gps); - if (rcu_cpu_stall_ftrace_dump) + if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) rcu_ftrace_dump(DUMP_ALL); } } diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 2de49b5d8dd2..5f7713a27dbb 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -53,19 +53,6 @@ #endif #define MODULE_PARAM_PREFIX "rcupdate." -#ifndef data_race -#define data_race(expr) \ - ({ \ - expr; \ - }) -#endif -#ifndef ASSERT_EXCLUSIVE_WRITER -#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0) -#endif -#ifndef ASSERT_EXCLUSIVE_ACCESS -#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0) -#endif - #ifndef CONFIG_TINY_RCU module_param(rcu_expedited, int, 0); module_param(rcu_normal, int, 0); 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 e07779a62634..6dc2b49b85ea 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh @@ -66,6 +66,7 @@ config_override_param () { echo > $T/KcList config_override_param "$config_dir/CFcommon" KcList "`cat $config_dir/CFcommon 2> /dev/null`" config_override_param "$config_template" KcList "`cat $config_template 2> /dev/null`" +config_override_param "--gdb options" KcList "$TORTURE_KCONFIG_GDB_ARG" config_override_param "--kasan options" KcList "$TORTURE_KCONFIG_KASAN_ARG" config_override_param "--kcsan options" KcList "$TORTURE_KCONFIG_KCSAN_ARG" config_override_param "--kconfig argument" KcList "$TORTURE_KCONFIG_ARG" @@ -152,7 +153,11 @@ qemu_append="`identify_qemu_append "$QEMU"`" boot_args="`configfrag_boot_params "$boot_args" "$config_template"`" # Generate kernel-version-specific boot parameters boot_args="`per_version_boot_params "$boot_args" $resdir/.config $seconds`" -echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd +if test -n "$TORTURE_BOOT_GDB_ARG" +then + boot_args="$boot_args $TORTURE_BOOT_GDB_ARG" +fi +echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" $TORTURE_QEMU_GDB_ARG > $resdir/qemu-cmd if test -n "$TORTURE_BUILDONLY" then @@ -171,14 +176,26 @@ echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log # Attempt to run qemu ( . $T/qemu-cmd; 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" +if test -z "$TORTURE_KCONFIG_GDB_ARG" then - qemu_pid=`cat "$resdir/qemu_pid"` - echo Monitoring qemu job at pid $qemu_pid -else - qemu_pid="" - echo Monitoring qemu job at yet-as-unknown pid + sleep 10 # Give qemu's pid a chance to reach the file + if test -s "$resdir/qemu_pid" + then + qemu_pid=`cat "$resdir/qemu_pid"` + echo Monitoring qemu job at pid $qemu_pid + else + qemu_pid="" + echo Monitoring qemu job at yet-as-unknown pid + fi +fi +if test -n "$TORTURE_KCONFIG_GDB_ARG" +then + echo Waiting for you to attach a debug session, for example: > /dev/tty + echo " gdb $base_resdir/vmlinux" > /dev/tty + echo 'After symbols load and the "(gdb)" prompt appears:' > /dev/tty + echo " target remote :1234" > /dev/tty + echo " continue" > /dev/tty + kstarttime=`gawk 'BEGIN { print systime() }' < /dev/null` fi while : do diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh index e655983b7429..c30047e52b54 100755 --- a/tools/testing/selftests/rcutorture/bin/kvm.sh +++ b/tools/testing/selftests/rcutorture/bin/kvm.sh @@ -31,6 +31,9 @@ TORTURE_DEFCONFIG=defconfig TORTURE_BOOT_IMAGE="" TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD TORTURE_KCONFIG_ARG="" +TORTURE_KCONFIG_GDB_ARG="" +TORTURE_BOOT_GDB_ARG="" +TORTURE_QEMU_GDB_ARG="" TORTURE_KCONFIG_KASAN_ARG="" TORTURE_KCONFIG_KCSAN_ARG="" TORTURE_KMAKE_ARG="" @@ -46,6 +49,7 @@ jitter="-1" usage () { echo "Usage: $scriptname optional arguments:" + echo " --allcpus" echo " --bootargs kernel-boot-arguments" echo " --bootimage relative-path-to-kernel-boot-image" echo " --buildonly" @@ -55,17 +59,19 @@ usage () { echo " --defconfig string" echo " --dryrun sched|script" echo " --duration minutes" + echo " --gdb" + echo " --help" echo " --interactive" echo " --jitter N [ maxsleep (us) [ maxspin (us) ] ]" echo " --kconfig Kconfig-options" echo " --kmake-arg kernel-make-arguments" echo " --mac nn:nn:nn:nn:nn:nn" - echo " --memory megabytes | nnnG" + echo " --memory megabytes|nnnG" echo " --no-initrd" echo " --qemu-args qemu-arguments" echo " --qemu-cmd qemu-system-..." echo " --results absolute-pathname" - echo " --torture rcu" + echo " --torture lock|rcu|rcuperf|refscale|scf" echo " --trust-make" exit 1 } @@ -126,6 +132,14 @@ do dur=$(($2*60)) shift ;; + --gdb) + TORTURE_KCONFIG_GDB_ARG="CONFIG_DEBUG_INFO=y"; export TORTURE_KCONFIG_GDB_ARG + TORTURE_BOOT_GDB_ARG="nokaslr"; export TORTURE_BOOT_GDB_ARG + TORTURE_QEMU_GDB_ARG="-s -S"; export TORTURE_QEMU_GDB_ARG + ;; + --help|-h) + usage + ;; --interactive) TORTURE_QEMU_INTERACTIVE=1; export TORTURE_QEMU_INTERACTIVE ;; @@ -248,6 +262,15 @@ do done touch $T/cfgcpu configs_derep="`echo $configs_derep | sed -e "s/\<CFLIST\>/$defaultconfigs/g"`" +if test -n "$TORTURE_KCONFIG_GDB_ARG" +then + if test "`echo $configs_derep | wc -w`" -gt 1 + then + echo "The --config list is: $configs_derep." + echo "Only one --config permitted with --gdb, terminating." + exit 1 + fi +fi for CF1 in $configs_derep do if test -f "$CONFIGFRAG/$CF1" @@ -323,6 +346,9 @@ TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG TORTURE_INITRD="$TORTURE_INITRD"; export TORTURE_INITRD TORTURE_KCONFIG_ARG="$TORTURE_KCONFIG_ARG"; export TORTURE_KCONFIG_ARG +TORTURE_KCONFIG_GDB_ARG="$TORTURE_KCONFIG_GDB_ARG"; export TORTURE_KCONFIG_GDB_ARG +TORTURE_BOOT_GDB_ARG="$TORTURE_BOOT_GDB_ARG"; export TORTURE_BOOT_GDB_ARG +TORTURE_QEMU_GDB_ARG="$TORTURE_QEMU_GDB_ARG"; export TORTURE_QEMU_GDB_ARG TORTURE_KCONFIG_KASAN_ARG="$TORTURE_KCONFIG_KASAN_ARG"; export TORTURE_KCONFIG_KASAN_ARG TORTURE_KCONFIG_KCSAN_ARG="$TORTURE_KCONFIG_KCSAN_ARG"; export TORTURE_KCONFIG_KCSAN_ARG TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 index 2dde0d9964e3..4f95f8544f3f 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE05 @@ -16,5 +16,6 @@ CONFIG_RCU_NOCB_CPU=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y #CHECK#CONFIG_PROVE_RCU=y +CONFIG_PROVE_RCU_LIST=y CONFIG_DEBUG_OBJECTS_RCU_HEAD=n CONFIG_RCU_EXPERT=y diff --git a/tools/testing/selftests/rcutorture/doc/initrd.txt b/tools/testing/selftests/rcutorture/doc/initrd.txt index 933b4fd12327..41a4255865d4 100644 --- a/tools/testing/selftests/rcutorture/doc/initrd.txt +++ b/tools/testing/selftests/rcutorture/doc/initrd.txt @@ -1,12 +1,11 @@ -The rcutorture scripting tools automatically create the needed initrd -directory using dracut. Failing that, this tool will create an initrd -containing a single statically linked binary named "init" that loops -over a very long sleep() call. In both cases, this creation is done -by tools/testing/selftests/rcutorture/bin/mkinitrd.sh. +The rcutorture scripting tools automatically create an initrd containing +a single statically linked binary named "init" that loops over a +very long sleep() call. In both cases, this creation is done by +tools/testing/selftests/rcutorture/bin/mkinitrd.sh. -However, if you are attempting to run rcutorture on a system that does -not have dracut installed, and if you don't like the notion of static -linking, you might wish to press an existing initrd into service: +However, if you don't like the notion of statically linked bare-bones +userspace environments, you might wish to press an existing initrd +into service: ------------------------------------------------------------------------ cd tools/testing/selftests/rcutorture @@ -15,24 +14,3 @@ mkdir initrd cd initrd cpio -id < /tmp/initrd.img.zcat # Manually verify that initrd contains needed binaries and libraries. ------------------------------------------------------------------------- - -Interestingly enough, if you are running rcutorture, you don't really -need userspace in many cases. Running without userspace has the -advantage of allowing you to test your kernel independently of the -distro in place, the root-filesystem layout, and so on. To make this -happen, put the following script in the initrd's tree's "/init" file, -with 0755 mode. - ------------------------------------------------------------------------- -#!/bin/sh - -while : -do - sleep 10 -done ------------------------------------------------------------------------- - -This approach also allows most of the binaries and libraries in the -initrd filesystem to be dispensed with, which can save significant -space in rcutorture's "res" directory. diff --git a/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt b/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt index 449cf579d6f9..b2fc247976b1 100644 --- a/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt +++ b/tools/testing/selftests/rcutorture/doc/rcu-test-image.txt @@ -1,8 +1,33 @@ -This document describes one way to create the rcu-test-image file -that contains the filesystem used by the guest-OS kernel. There are -probably much better ways of doing this, and this filesystem could no -doubt be smaller. It is probably also possible to simply download -an appropriate image from any number of places. +Normally, a minimal initrd is created automatically by the rcutorture +scripting. But minimal really does mean "minimal", namely just a single +root directory with a single statically linked executable named "init": + +$ size tools/testing/selftests/rcutorture/initrd/init + text data bss dec hex filename + 328 0 8 336 150 tools/testing/selftests/rcutorture/initrd/init + +Suppose you need to run some scripts, perhaps to monitor or control +some aspect of the rcutorture testing. This will require a more fully +filled-out userspace, perhaps containing libraries, executables for +the shell and other utilities, and soforth. In that case, place your +desired filesystem here: + + tools/testing/selftests/rcutorture/initrd + +For example, your tools/testing/selftests/rcutorture/initrd/init might +be a script that does any needed mount operations and starts whatever +scripts need starting to properly monitor or control your testing. +The next rcutorture build will then incorporate this filesystem into +the kernel image that is passed to qemu. + +Or maybe you need a real root filesystem for some reason, in which case +please read on! + +The remainder of this document describes one way to create the +rcu-test-image file that contains the filesystem used by the guest-OS +kernel. There are probably much better ways of doing this, and this +filesystem could no doubt be smaller. It is probably also possible to +simply download an appropriate image from any number of places. That said, here are the commands: @@ -36,7 +61,7 @@ References: https://help.ubuntu.com/community/JeOSVMBuilder http://wiki.libvirt.org/page/UbuntuKVMWalkthrough http://www.moe.co.uk/2011/01/07/pci_add_option_rom-failed-to-find-romfile-pxe-rtl8139-bin/ -- "apt-get install kvm-pxe" - http://www.landley.net/writing/rootfs-howto.html - http://en.wikipedia.org/wiki/Initrd - http://en.wikipedia.org/wiki/Cpio + https://www.landley.net/writing/rootfs-howto.html + https://en.wikipedia.org/wiki/Initrd + https://en.wikipedia.org/wiki/Cpio http://wiki.libvirt.org/page/UbuntuKVMWalkthrough |