diff options
Diffstat (limited to 'kernel/rcu/rcutorture.c')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 243 |
1 files changed, 123 insertions, 120 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index a02a2f21386b..210c77460365 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -66,15 +66,19 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@jos /* 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) -#define RCUTORTURE_RDR_BH 0x1 /* Extend readers by disabling bh. */ -#define RCUTORTURE_RDR_IRQ 0x2 /* ... disabling interrupts. */ -#define RCUTORTURE_RDR_PREEMPT 0x4 /* ... disabling preemption. */ -#define RCUTORTURE_RDR_RCU 0x8 /* ... entering another RCU reader. */ -#define RCUTORTURE_RDR_NBITS 4 /* Number of bits defined above. */ -#define RCUTORTURE_MAX_EXTEND (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | \ - RCUTORTURE_RDR_PREEMPT) +#define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */ +#define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */ +#define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */ +#define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */ +#define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */ +#define RCUTORTURE_RDR_RCU 0x20 /* ... entering another RCU reader. */ +#define RCUTORTURE_RDR_NBITS 6 /* Number of bits defined above. */ +#define RCUTORTURE_MAX_EXTEND \ + (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ + RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ /* Must be power of two minus one. */ +#define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) torture_param(int, cbflood_inter_holdoff, HZ, "Holdoff between floods (jiffies)"); @@ -131,7 +135,7 @@ torture_param(int, verbose, 1, static char *torture_type = "rcu"; module_param(torture_type, charp, 0444); -MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)"); +MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); static int nrealreaders; static int ncbflooders; @@ -204,6 +208,18 @@ static const char * const rcu_torture_writer_state_names[] = { "RTWS_STOPPING", }; +/* Record reader segment types and duration for first failing read. */ +struct rt_read_seg { + int rt_readstate; + unsigned long rt_delay_jiffies; + unsigned long rt_delay_ms; + unsigned long rt_delay_us; + bool rt_preempted; +}; +static int err_segs_recorded; +static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; +static int rt_read_nsegs; + static const char *rcu_torture_writer_state_getname(void) { unsigned int i = READ_ONCE(rcu_torture_writer_state); @@ -285,7 +301,8 @@ struct rcu_torture_ops { void (*init)(void); void (*cleanup)(void); int (*readlock)(void); - void (*read_delay)(struct torture_random_state *rrsp); + void (*read_delay)(struct torture_random_state *rrsp, + struct rt_read_seg *rtrsp); void (*readunlock)(int idx); unsigned long (*get_gp_seq)(void); unsigned long (*gp_diff)(unsigned long new, unsigned long old); @@ -318,7 +335,8 @@ static int rcu_torture_read_lock(void) __acquires(RCU) return 0; } -static void rcu_read_delay(struct torture_random_state *rrsp) +static void +rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) { unsigned long started; unsigned long completed; @@ -336,15 +354,20 @@ static void rcu_read_delay(struct torture_random_state *rrsp) if (preempt_count() & (SOFTIRQ_MASK | HARDIRQ_MASK)) longdelay_ms = 5; /* Avoid triggering BH limits. */ mdelay(longdelay_ms); + rtrsp->rt_delay_ms = longdelay_ms; completed = cur_ops->get_gp_seq(); do_trace_rcu_torture_read(cur_ops->name, NULL, ts, started, completed); } - if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) + if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { udelay(shortdelay_us); + rtrsp->rt_delay_us = shortdelay_us; + } if (!preempt_count() && - !(torture_random(rrsp) % (nrealreaders * 500))) + !(torture_random(rrsp) % (nrealreaders * 500))) { torture_preempt_schedule(); /* QS only if preemptible. */ + rtrsp->rt_preempted = true; + } } static void rcu_torture_read_unlock(int idx) __releases(RCU) @@ -442,51 +465,11 @@ static struct rcu_torture_ops rcu_ops = { .stall_dur = rcu_jiffies_till_stall_check, .irq_capable = 1, .can_boost = rcu_can_boost(), + .extendables = RCUTORTURE_MAX_EXTEND, .name = "rcu" }; /* - * Definitions for rcu_bh torture testing. - */ - -static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) -{ - rcu_read_lock_bh(); - return 0; -} - -static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) -{ - rcu_read_unlock_bh(); -} - -static void rcu_bh_torture_deferred_free(struct rcu_torture *p) -{ - call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); -} - -static struct rcu_torture_ops rcu_bh_ops = { - .ttype = RCU_BH_FLAVOR, - .init = rcu_sync_torture_init, - .readlock = rcu_bh_torture_read_lock, - .read_delay = rcu_read_delay, /* just reuse rcu's version. */ - .readunlock = rcu_bh_torture_read_unlock, - .get_gp_seq = rcu_bh_get_gp_seq, - .gp_diff = rcu_seq_diff, - .deferred_free = rcu_bh_torture_deferred_free, - .sync = synchronize_rcu_bh, - .exp_sync = synchronize_rcu_bh_expedited, - .call = call_rcu_bh, - .cb_barrier = rcu_barrier_bh, - .fqs = rcu_bh_force_quiescent_state, - .stats = NULL, - .irq_capable = 1, - .extendables = (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ), - .ext_irq_conflict = RCUTORTURE_RDR_RCU, - .name = "rcu_bh" -}; - -/* * Don't even think about trying any of these in real life!!! * The names includes "busted", and they really means it! * The only purpose of these functions is to provide a buggy RCU @@ -542,7 +525,8 @@ static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) return srcu_read_lock(srcu_ctlp); } -static void srcu_read_delay(struct torture_random_state *rrsp) +static void +srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) { long delay; const long uspertick = 1000000 / HZ; @@ -552,10 +536,12 @@ static void srcu_read_delay(struct torture_random_state *rrsp) delay = torture_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); - if (!delay && in_task()) + if (!delay && in_task()) { schedule_timeout_interruptible(longdelay); - else - rcu_read_delay(rrsp); + rtrsp->rt_delay_jiffies = longdelay; + } else { + rcu_read_delay(rrsp, rtrsp); + } } static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) @@ -674,48 +660,6 @@ static struct rcu_torture_ops busted_srcud_ops = { }; /* - * Definitions for sched torture testing. - */ - -static int sched_torture_read_lock(void) -{ - preempt_disable(); - return 0; -} - -static void sched_torture_read_unlock(int idx) -{ - preempt_enable(); -} - -static void rcu_sched_torture_deferred_free(struct rcu_torture *p) -{ - call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); -} - -static struct rcu_torture_ops sched_ops = { - .ttype = RCU_SCHED_FLAVOR, - .init = rcu_sync_torture_init, - .readlock = sched_torture_read_lock, - .read_delay = rcu_read_delay, /* just reuse rcu's version. */ - .readunlock = sched_torture_read_unlock, - .get_gp_seq = rcu_sched_get_gp_seq, - .gp_diff = rcu_seq_diff, - .deferred_free = rcu_sched_torture_deferred_free, - .sync = synchronize_sched, - .exp_sync = synchronize_sched_expedited, - .get_state = get_state_synchronize_sched, - .cond_sync = cond_synchronize_sched, - .call = call_rcu_sched, - .cb_barrier = rcu_barrier_sched, - .fqs = rcu_sched_force_quiescent_state, - .stats = NULL, - .irq_capable = 1, - .extendables = RCUTORTURE_MAX_EXTEND, - .name = "sched" -}; - -/* * Definitions for RCU-tasks torture testing. */ @@ -1214,7 +1158,8 @@ static void rcu_torture_timer_cb(struct rcu_head *rhp) * change, do a ->read_delay(). */ static void rcutorture_one_extend(int *readstate, int newstate, - struct torture_random_state *trsp) + struct torture_random_state *trsp, + struct rt_read_seg *rtrsp) { int idxnew = -1; int idxold = *readstate; @@ -1223,6 +1168,7 @@ static void rcutorture_one_extend(int *readstate, int newstate, WARN_ON_ONCE(idxold < 0); WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 1); + rtrsp->rt_readstate = newstate; /* First, put new protection in place to avoid critical-section gap. */ if (statesnew & RCUTORTURE_RDR_BH) @@ -1231,6 +1177,10 @@ static void rcutorture_one_extend(int *readstate, int newstate, local_irq_disable(); if (statesnew & RCUTORTURE_RDR_PREEMPT) preempt_disable(); + if (statesnew & RCUTORTURE_RDR_RBH) + rcu_read_lock_bh(); + if (statesnew & RCUTORTURE_RDR_SCHED) + rcu_read_lock_sched(); if (statesnew & RCUTORTURE_RDR_RCU) idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT; @@ -1241,12 +1191,16 @@ static void rcutorture_one_extend(int *readstate, int newstate, local_bh_enable(); if (statesold & RCUTORTURE_RDR_PREEMPT) preempt_enable(); + if (statesold & RCUTORTURE_RDR_RBH) + rcu_read_unlock_bh(); + if (statesold & RCUTORTURE_RDR_SCHED) + rcu_read_unlock_sched(); if (statesold & RCUTORTURE_RDR_RCU) cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT); /* Delay if neither beginning nor end and there was a change. */ if ((statesnew || statesold) && *readstate && newstate) - cur_ops->read_delay(trsp); + cur_ops->read_delay(trsp, rtrsp); /* Update the reader state. */ if (idxnew == -1) @@ -1275,18 +1229,19 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) { int mask = rcutorture_extend_mask_max(); unsigned long randmask1 = torture_random(trsp) >> 8; - unsigned long randmask2 = randmask1 >> 1; + unsigned long randmask2 = randmask1 >> 3; WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT); - /* Half the time lots of bits, half the time only one bit. */ - if (randmask1 & 0x1) + /* Most of the time lots of bits, half the time only one bit. */ + if (!(randmask1 & 0x7)) mask = mask & randmask2; else mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); + /* Can't enable bh w/irq disabled. */ if ((mask & RCUTORTURE_RDR_IRQ) && - !(mask & RCUTORTURE_RDR_BH) && - (oldmask & RCUTORTURE_RDR_BH)) - mask |= RCUTORTURE_RDR_BH; /* Can't enable bh w/irq disabled. */ + ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) || + (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH)))) + mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; if ((mask & RCUTORTURE_RDR_IRQ) && !(mask & cur_ops->ext_irq_conflict) && (oldmask & cur_ops->ext_irq_conflict)) @@ -1298,20 +1253,25 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) * Do a randomly selected number of extensions of an existing RCU read-side * critical section. */ -static void rcutorture_loop_extend(int *readstate, - struct torture_random_state *trsp) +static struct rt_read_seg * +rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, + struct rt_read_seg *rtrsp) { int i; + int j; int mask = rcutorture_extend_mask_max(); WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ if (!((mask - 1) & mask)) - return; /* Current RCU flavor not extendable. */ - i = (torture_random(trsp) >> 3) & RCUTORTURE_RDR_MAX_LOOPS; - while (i--) { + return rtrsp; /* Current RCU reader not extendable. */ + /* Bias towards larger numbers of loops. */ + i = (torture_random(trsp) >> 3); + i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; + for (j = 0; j < i; j++) { mask = rcutorture_extend_mask(*readstate, trsp); - rcutorture_one_extend(readstate, mask, trsp); + rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); } + return &rtrsp[j]; } /* @@ -1321,16 +1281,20 @@ static void rcutorture_loop_extend(int *readstate, */ static bool rcu_torture_one_read(struct torture_random_state *trsp) { + int i; unsigned long started; unsigned long completed; int newstate; struct rcu_torture *p; int pipe_count; int readstate = 0; + struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } }; + struct rt_read_seg *rtrsp = &rtseg[0]; + struct rt_read_seg *rtrsp1; unsigned long long ts; newstate = rcutorture_extend_mask(readstate, trsp); - rcutorture_one_extend(&readstate, newstate, trsp); + rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++); started = cur_ops->get_gp_seq(); ts = rcu_trace_clock_local(); p = rcu_dereference_check(rcu_torture_current, @@ -1340,12 +1304,12 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp) torturing_tasks()); if (p == NULL) { /* Wait for rcu_torture_writer to get underway */ - rcutorture_one_extend(&readstate, 0, trsp); + rcutorture_one_extend(&readstate, 0, trsp, rtrsp); return false; } if (p->rtort_mbtest == 0) atomic_inc(&n_rcu_torture_mberror); - rcutorture_loop_extend(&readstate, trsp); + rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp); preempt_disable(); pipe_count = p->rtort_pipe_count; if (pipe_count > RCU_TORTURE_PIPE_LEN) { @@ -1366,8 +1330,17 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp) } __this_cpu_inc(rcu_torture_batch[completed]); preempt_enable(); - rcutorture_one_extend(&readstate, 0, trsp); + rcutorture_one_extend(&readstate, 0, trsp, rtrsp); WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK); + + /* If error or close call, record the sequence of reader protections. */ + if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { + i = 0; + for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++) + err_segs[i++] = *rtrsp1; + rt_read_nsegs = i; + } + return true; } @@ -1956,6 +1929,7 @@ static enum cpuhp_state rcutor_hp; static void rcu_torture_cleanup(void) { + int firsttime; int flags = 0; unsigned long gp_seq = 0; int i; @@ -2000,7 +1974,7 @@ rcu_torture_cleanup(void) cpuhp_remove_state(rcutor_hp); /* - * Wait for all RCU callbacks to fire, then do flavor-specific + * Wait for all RCU callbacks to fire, then do torture-type-specific * cleanup operations. */ if (cur_ops->cb_barrier != NULL) @@ -2010,6 +1984,33 @@ rcu_torture_cleanup(void) rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ + if (err_segs_recorded) { + pr_alert("Failure/close-call rcutorture reader segments:\n"); + if (rt_read_nsegs == 0) + pr_alert("\t: No segments recorded!!!\n"); + firsttime = 1; + for (i = 0; i < rt_read_nsegs; i++) { + pr_alert("\t%d: %#x ", i, err_segs[i].rt_readstate); + if (err_segs[i].rt_delay_jiffies != 0) { + pr_cont("%s%ldjiffies", firsttime ? "" : "+", + err_segs[i].rt_delay_jiffies); + firsttime = 0; + } + if (err_segs[i].rt_delay_ms != 0) { + pr_cont("%s%ldms", firsttime ? "" : "+", + err_segs[i].rt_delay_ms); + firsttime = 0; + } + if (err_segs[i].rt_delay_us != 0) { + pr_cont("%s%ldus", firsttime ? "" : "+", + err_segs[i].rt_delay_us); + firsttime = 0; + } + pr_cont("%s\n", + err_segs[i].rt_preempted ? "preempted" : ""); + + } + } if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); else if (torture_onoff_failures()) @@ -2083,8 +2084,8 @@ rcu_torture_init(void) int cpu; int firsterr = 0; static struct rcu_torture_ops *torture_ops[] = { - &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, - &busted_srcud_ops, &sched_ops, &tasks_ops, + &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, + &busted_srcud_ops, &tasks_ops, }; if (!torture_init_begin(torture_type, verbose)) @@ -2154,6 +2155,8 @@ rcu_torture_init(void) per_cpu(rcu_torture_batch, cpu)[i] = 0; } } + err_segs_recorded = 0; + rt_read_nsegs = 0; /* Start up the kthreads. */ |