rcutorture: Add forward-progress checking for writer
The rcutorture output currently does not distinguish between stalls in the RCU implementation and stalls in the rcu_torture_writer() kthreads. This commit therefore adds some diagnostics to help distinguish between these two conditions, at least for the non-SRCU implementations. (SRCU does not provide evidence of update-side forward progress by design.) Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
Родитель
c9eaa447e7
Коммит
ad0dc7f94d
|
|
@ -51,7 +51,17 @@ extern int rcu_expedited; /* for sysctl */
|
|||
extern int rcutorture_runnable; /* for sysctl */
|
||||
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
|
||||
|
||||
enum rcutorture_type {
|
||||
RCU_FLAVOR,
|
||||
RCU_BH_FLAVOR,
|
||||
RCU_SCHED_FLAVOR,
|
||||
SRCU_FLAVOR,
|
||||
INVALID_RCU_FLAVOR
|
||||
};
|
||||
|
||||
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
|
||||
void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
|
||||
unsigned long *gpnum, unsigned long *completed);
|
||||
void rcutorture_record_test_transition(void);
|
||||
void rcutorture_record_progress(unsigned long vernum);
|
||||
void do_trace_rcu_torture_read(const char *rcutorturename,
|
||||
|
|
@ -60,6 +70,15 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
|
|||
unsigned long c_old,
|
||||
unsigned long c);
|
||||
#else
|
||||
static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
|
||||
int *flags,
|
||||
unsigned long *gpnum,
|
||||
unsigned long *completed)
|
||||
{
|
||||
*flags = 0;
|
||||
*gpnum = 0;
|
||||
*completed = 0;
|
||||
}
|
||||
static inline void rcutorture_record_test_transition(void)
|
||||
{
|
||||
}
|
||||
|
|
|
|||
|
|
@ -138,6 +138,15 @@ static long n_barrier_attempts;
|
|||
static long n_barrier_successes;
|
||||
static struct list_head rcu_torture_removed;
|
||||
|
||||
static int rcu_torture_writer_state;
|
||||
#define RTWS_FIXED_DELAY 0
|
||||
#define RTWS_DELAY 1
|
||||
#define RTWS_REPLACE 2
|
||||
#define RTWS_DEF_FREE 3
|
||||
#define RTWS_EXP_SYNC 4
|
||||
#define RTWS_STUTTER 5
|
||||
#define RTWS_STOPPING 6
|
||||
|
||||
#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
|
||||
#define RCUTORTURE_RUNNABLE_INIT 1
|
||||
#else
|
||||
|
|
@ -214,6 +223,7 @@ rcu_torture_free(struct rcu_torture *p)
|
|||
*/
|
||||
|
||||
struct rcu_torture_ops {
|
||||
int ttype;
|
||||
void (*init)(void);
|
||||
int (*readlock)(void);
|
||||
void (*read_delay)(struct torture_random_state *rrsp);
|
||||
|
|
@ -312,6 +322,7 @@ static void rcu_sync_torture_init(void)
|
|||
}
|
||||
|
||||
static struct rcu_torture_ops rcu_ops = {
|
||||
.ttype = RCU_FLAVOR,
|
||||
.init = rcu_sync_torture_init,
|
||||
.readlock = rcu_torture_read_lock,
|
||||
.read_delay = rcu_read_delay,
|
||||
|
|
@ -355,6 +366,7 @@ static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
|
|||
}
|
||||
|
||||
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. */
|
||||
|
|
@ -397,6 +409,7 @@ call_rcu_busted(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
|
|||
}
|
||||
|
||||
static struct rcu_torture_ops rcu_busted_ops = {
|
||||
.ttype = INVALID_RCU_FLAVOR,
|
||||
.init = rcu_sync_torture_init,
|
||||
.readlock = rcu_torture_read_lock,
|
||||
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
|
||||
|
|
@ -492,6 +505,7 @@ static void srcu_torture_synchronize_expedited(void)
|
|||
}
|
||||
|
||||
static struct rcu_torture_ops srcu_ops = {
|
||||
.ttype = SRCU_FLAVOR,
|
||||
.init = rcu_sync_torture_init,
|
||||
.readlock = srcu_torture_read_lock,
|
||||
.read_delay = srcu_read_delay,
|
||||
|
|
@ -527,6 +541,7 @@ static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
|
|||
}
|
||||
|
||||
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. */
|
||||
|
|
@ -699,12 +714,15 @@ rcu_torture_writer(void *arg)
|
|||
set_user_nice(current, MAX_NICE);
|
||||
|
||||
do {
|
||||
rcu_torture_writer_state = RTWS_FIXED_DELAY;
|
||||
schedule_timeout_uninterruptible(1);
|
||||
rp = rcu_torture_alloc();
|
||||
if (rp == NULL)
|
||||
continue;
|
||||
rp->rtort_pipe_count = 0;
|
||||
rcu_torture_writer_state = RTWS_DELAY;
|
||||
udelay(torture_random(&rand) & 0x3ff);
|
||||
rcu_torture_writer_state = RTWS_REPLACE;
|
||||
old_rp = rcu_dereference_check(rcu_torture_current,
|
||||
current == writer_task);
|
||||
rp->rtort_mbtest = 1;
|
||||
|
|
@ -721,8 +739,10 @@ rcu_torture_writer(void *arg)
|
|||
else
|
||||
exp = gp_exp;
|
||||
if (!exp) {
|
||||
rcu_torture_writer_state = RTWS_DEF_FREE;
|
||||
cur_ops->deferred_free(old_rp);
|
||||
} else {
|
||||
rcu_torture_writer_state = RTWS_EXP_SYNC;
|
||||
cur_ops->exp_sync();
|
||||
list_add(&old_rp->rtort_free,
|
||||
&rcu_torture_removed);
|
||||
|
|
@ -743,8 +763,10 @@ rcu_torture_writer(void *arg)
|
|||
}
|
||||
}
|
||||
rcutorture_record_progress(++rcu_torture_current_version);
|
||||
rcu_torture_writer_state = RTWS_STUTTER;
|
||||
stutter_wait("rcu_torture_writer");
|
||||
} while (!torture_must_stop());
|
||||
rcu_torture_writer_state = RTWS_STOPPING;
|
||||
torture_kthread_stopping("rcu_torture_writer");
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -937,6 +959,7 @@ rcu_torture_printk(char *page)
|
|||
int i;
|
||||
long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
|
||||
long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
|
||||
static unsigned long rtcv_snap = ULONG_MAX;
|
||||
|
||||
for_each_possible_cpu(cpu) {
|
||||
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
|
||||
|
|
@ -997,6 +1020,20 @@ rcu_torture_printk(char *page)
|
|||
page += sprintf(page, "\n");
|
||||
if (cur_ops->stats)
|
||||
cur_ops->stats(page);
|
||||
if (rtcv_snap == rcu_torture_current_version &&
|
||||
rcu_torture_current != NULL) {
|
||||
int __maybe_unused flags;
|
||||
unsigned long __maybe_unused gpnum;
|
||||
unsigned long __maybe_unused completed;
|
||||
|
||||
rcutorture_get_gp_data(cur_ops->ttype,
|
||||
&flags, &gpnum, &completed);
|
||||
page += sprintf(page,
|
||||
"??? Writer stall state %d g%lu c%lu f%#x\n",
|
||||
rcu_torture_writer_state,
|
||||
gpnum, completed, flags);
|
||||
}
|
||||
rtcv_snap = rcu_torture_current_version;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -293,6 +293,39 @@ void rcutorture_record_test_transition(void)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(rcutorture_record_test_transition);
|
||||
|
||||
/*
|
||||
* Send along grace-period-related data for rcutorture diagnostics.
|
||||
*/
|
||||
void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,
|
||||
unsigned long *gpnum, unsigned long *completed)
|
||||
{
|
||||
struct rcu_state *rsp = NULL;
|
||||
|
||||
switch (test_type) {
|
||||
case RCU_FLAVOR:
|
||||
rsp = rcu_state;
|
||||
break;
|
||||
case RCU_BH_FLAVOR:
|
||||
rsp = &rcu_bh_state;
|
||||
break;
|
||||
case RCU_SCHED_FLAVOR:
|
||||
rsp = &rcu_sched_state;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
if (rsp != NULL) {
|
||||
*flags = ACCESS_ONCE(rsp->gp_flags);
|
||||
*gpnum = ACCESS_ONCE(rsp->gpnum);
|
||||
*completed = ACCESS_ONCE(rsp->completed);
|
||||
return;
|
||||
}
|
||||
*flags = 0;
|
||||
*gpnum = 0;
|
||||
*completed = 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(rcutorture_get_gp_data);
|
||||
|
||||
/*
|
||||
* Record the number of writer passes through the current rcutorture test.
|
||||
* This is also used to correlate debugfs tracing stats with the rcutorture
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче