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Commit 4a298656 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Paul E. McKenney
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rcu: make rcutorture version numbers available through debugfs 



It is not possible to accurately correlate rcutorture output with that
of debugfs.  This patch therefore adds a debugfs file that prints out
the rcutorture version number, permitting easy correlation.

Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent d71df90e

include/linux/rcupdate.h

+12 −1
Original line number Diff line number Diff line
@@ -47,6 +47,18 @@ 
extern int rcutorture_runnable; /* for sysctl */

#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */



#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)

extern void rcutorture_record_test_transition(void);

extern void rcutorture_record_progress(unsigned long vernum);

#else

static inline void rcutorture_record_test_transition(void)

{

}

static inline void rcutorture_record_progress(unsigned long vernum)

{

}

#endif



#define UINT_CMP_GE(a, b)	(UINT_MAX / 2 >= (a) - (b))

#define UINT_CMP_LT(a, b)	(UINT_MAX / 2 < (a) - (b))

#define ULONG_CMP_GE(a, b)	(ULONG_MAX / 2 >= (a) - (b))
@@ -68,7 +80,6 @@ extern void call_rcu_sched(struct rcu_head *head, 
extern void synchronize_sched(void);

extern void rcu_barrier_bh(void);

extern void rcu_barrier_sched(void);

extern int sched_expedited_torture_stats(char *page);



static inline void __rcu_read_lock_bh(void)

{

include/linux/rcutree.h

+3 −0
Original line number Diff line number Diff line
@@ -58,9 +58,12 @@ static inline void synchronize_rcu_bh_expedited(void) 


extern void rcu_barrier(void);



extern unsigned long rcutorture_testseq;

extern unsigned long rcutorture_vernum;

extern long rcu_batches_completed(void);

extern long rcu_batches_completed_bh(void);

extern long rcu_batches_completed_sched(void);



extern void rcu_force_quiescent_state(void);

extern void rcu_bh_force_quiescent_state(void);

extern void rcu_sched_force_quiescent_state(void);

kernel/rcutorture.c

+5 −3
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ struct rcu_torture { 


static LIST_HEAD(rcu_torture_freelist);

static struct rcu_torture __rcu *rcu_torture_current;

static long rcu_torture_current_version;

static unsigned long rcu_torture_current_version;

static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];

static DEFINE_SPINLOCK(rcu_torture_lock);

static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
@@ -884,7 +884,7 @@ rcu_torture_writer(void *arg) 
			old_rp->rtort_pipe_count++;

			cur_ops->deferred_free(old_rp);

		}

		rcu_torture_current_version++;

		rcutorture_record_progress(++rcu_torture_current_version);

		oldbatch = cur_ops->completed();

		rcu_stutter_wait("rcu_torture_writer");

	} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
@@ -1064,7 +1064,7 @@ rcu_torture_printk(char *page) 
	}

	cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);

	cnt += sprintf(&page[cnt],

		       "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "

		       "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d "

		       "rtmbe: %d rtbke: %ld rtbre: %ld "

		       "rtbf: %ld rtb: %ld nt: %ld",

		       rcu_torture_current,
@@ -1325,6 +1325,7 @@ rcu_torture_cleanup(void) 
	int i;



	mutex_lock(&fullstop_mutex);

	rcutorture_record_test_transition();

	if (fullstop == FULLSTOP_SHUTDOWN) {

		printk(KERN_WARNING /* but going down anyway, so... */

		       "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
@@ -1616,6 +1617,7 @@ rcu_torture_init(void) 
		}

	}

	register_reboot_notifier(&rcutorture_shutdown_nb);

	rcutorture_record_test_transition();

	mutex_unlock(&fullstop_mutex);

	return 0;

kernel/rcutree.c

+37 −0
Original line number Diff line number Diff line
@@ -101,6 +101,18 @@ static void invoke_rcu_cpu_kthread(void); 


#define RCU_KTHREAD_PRIO 1	/* RT priority for per-CPU kthreads. */



/*

 * Track the rcutorture test sequence number and the update version

 * number within a given test.  The rcutorture_testseq is incremented

 * on every rcutorture module load and unload, so has an odd value

 * when a test is running.  The rcutorture_vernum is set to zero

 * when rcutorture starts and is incremented on each rcutorture update.

 * These variables enable correlating rcutorture output with the

 * RCU tracing information.

 */

unsigned long rcutorture_testseq;

unsigned long rcutorture_vernum;



/*

 * Return true if an RCU grace period is in progress.  The ACCESS_ONCE()s

 * permit this function to be invoked without holding the root rcu_node
@@ -192,6 +204,31 @@ void rcu_bh_force_quiescent_state(void) 
}

EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);



/*

 * Record the number of times rcutorture tests have been initiated and

 * terminated.  This information allows the debugfs tracing stats to be

 * correlated to the rcutorture messages, even when the rcutorture module

 * is being repeatedly loaded and unloaded.  In other words, we cannot

 * store this state in rcutorture itself.

 */

void rcutorture_record_test_transition(void)

{

	rcutorture_testseq++;

	rcutorture_vernum = 0;

}

EXPORT_SYMBOL_GPL(rcutorture_record_test_transition);



/*

 * Record the number of writer passes through the current rcutorture test.

 * This is also used to correlate debugfs tracing stats with the rcutorture

 * messages.

 */

void rcutorture_record_progress(unsigned long vernum)

{

	rcutorture_vernum++;

}

EXPORT_SYMBOL_GPL(rcutorture_record_progress);



/*

 * Force a quiescent state for RCU-sched.

 */

kernel/rcutree_trace.c

+28 −0
Original line number Diff line number Diff line
@@ -394,6 +394,29 @@ static const struct file_operations rcu_pending_fops = { 
	.release = single_release,

};



static int show_rcutorture(struct seq_file *m, void *unused)

{

	seq_printf(m, "rcutorture test sequence: %lu %s\n",

		   rcutorture_testseq >> 1,

		   (rcutorture_testseq & 0x1) ? "(test in progress)" : "");

	seq_printf(m, "rcutorture update version number: %lu\n",

		   rcutorture_vernum);

	return 0;

}



static int rcutorture_open(struct inode *inode, struct file *file)

{

	return single_open(file, show_rcutorture, NULL);

}



static const struct file_operations rcutorture_fops = {

	.owner = THIS_MODULE,

	.open = rcutorture_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

};



static struct dentry *rcudir;



static int __init rcutree_trace_init(void)
@@ -430,6 +453,11 @@ static int __init rcutree_trace_init(void) 
						NULL, &rcu_pending_fops);

	if (!retval)

		goto free_out;



	retval = debugfs_create_file("rcutorture", 0444, rcudir,

						NULL, &rcutorture_fops);

	if (!retval)

		goto free_out;

	return 0;

free_out:

	debugfs_remove_recursive(rcudir);