lockstat: contend with points (c7e78cff) · Commits · e / devices / android_kernel_oneplus_sm8150

Documentation/lockstat.txt

+32 −18

Original line number	Diff line number	Diff line
		@@ -71,34 +71,48 @@ Look at the current lock statistics:

		# less /proc/lock_stat

		01 lock_stat version 0.2
		01 lock_stat version 0.3
		02 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
		03 class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total
		04 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
		05
		06 &inode->i_data.tree_lock-W: 15 21657 0.18 1093295.30 11547131054.85 58 10415 0.16 87.51 6387.60
		07 &inode->i_data.tree_lock-R: 0 0 0.00 0.00 0.00 23302 231198 0.25 8.45 98023.38
		08 --------------------------
		09 &inode->i_data.tree_lock 0 [<ffffffff8027c08f>] add_to_page_cache+0x5f/0x190
		10
		11 ...............................................................................................................................................................................................
		12
		13 dcache_lock: 1037 1161 0.38 45.32 774.51 6611 243371 0.15 306.48 77387.24
		14 -----------
		15 dcache_lock 180 [<ffffffff802c0d7e>] sys_getcwd+0x11e/0x230
		16 dcache_lock 165 [<ffffffff802c002a>] d_alloc+0x15a/0x210
		17 dcache_lock 33 [<ffffffff8035818d>] _atomic_dec_and_lock+0x4d/0x70
		18 dcache_lock 1 [<ffffffff802beef8>] shrink_dcache_parent+0x18/0x130
		06 &mm->mmap_sem-W: 233 538 18446744073708 22924.27 607243.51 1342 45806 1.71 8595.89 1180582.34
		07 &mm->mmap_sem-R: 205 587 18446744073708 28403.36 731975.00 1940 412426 0.58 187825.45 6307502.88
		08 ---------------
		09 &mm->mmap_sem 487 [<ffffffff8053491f>] do_page_fault+0x466/0x928
		10 &mm->mmap_sem 179 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
		11 &mm->mmap_sem 279 [<ffffffff80210a57>] sys_mmap+0x75/0xce
		12 &mm->mmap_sem 76 [<ffffffff802a490b>] sys_munmap+0x32/0x59
		13 ---------------
		14 &mm->mmap_sem 270 [<ffffffff80210a57>] sys_mmap+0x75/0xce
		15 &mm->mmap_sem 431 [<ffffffff8053491f>] do_page_fault+0x466/0x928
		16 &mm->mmap_sem 138 [<ffffffff802a490b>] sys_munmap+0x32/0x59
		17 &mm->mmap_sem 145 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
		18
		19 ...............................................................................................................................................................................................
		20
		21 dcache_lock: 621 623 0.52 118.26 1053.02 6745 91930 0.29 316.29 118423.41
		22 -----------
		23 dcache_lock 179 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
		24 dcache_lock 113 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
		25 dcache_lock 99 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
		26 dcache_lock 104 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a
		27 -----------
		28 dcache_lock 192 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
		29 dcache_lock 98 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
		30 dcache_lock 72 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
		31 dcache_lock 112 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a

		This excerpt shows the first two lock class statistics. Line 01 shows the
		output version - each time the format changes this will be updated. Line 02-04
		show the header with column descriptions. Lines 05-10 and 13-18 show the actual
		show the header with column descriptions. Lines 05-18 and 20-31 show the actual
		statistics. These statistics come in two parts; the actual stats separated by a
		short separator (line 08, 14) from the contention points.
		short separator (line 08, 13) from the contention points.

		The first lock (05-10) is a read/write lock, and shows two lines above the
		The first lock (05-18) is a read/write lock, and shows two lines above the
		short separator. The contention points don't match the column descriptors,
		they have two: contentions and [<IP>] symbol.
		they have two: contentions and [<IP>] symbol. The second set of contention
		points are the points we're contending with.

		The integer part of the time values is in us.

include/linux/lockdep.h

+9 −4

Original line number	Diff line number	Diff line
		@@ -73,6 +73,8 @@ struct lock_class_key {
		struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
		};

		#define LOCKSTAT_POINTS 4

		/*
		* The lock-class itself:
		*/
		@@ -119,7 +121,8 @@ struct lock_class {
		int name_version;

		#ifdef CONFIG_LOCK_STAT
		unsigned long contention_point[4];
		unsigned long contention_point[LOCKSTAT_POINTS];
		unsigned long contending_point[LOCKSTAT_POINTS];
		#endif
		};

		@@ -144,6 +147,7 @@ enum bounce_type {

		struct lock_class_stats {
		unsigned long contention_point[4];
		unsigned long contending_point[4];
		struct lock_time read_waittime;
		struct lock_time write_waittime;
		struct lock_time read_holdtime;
		@@ -165,6 +169,7 @@ struct lockdep_map {
		const char *name;
		#ifdef CONFIG_LOCK_STAT
		int cpu;
		unsigned long ip;
		#endif
		};

		@@ -355,7 +360,7 @@ struct lock_class_key { };
		#ifdef CONFIG_LOCK_STAT

		extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
		extern void lock_acquired(struct lockdep_map *lock);
		extern void lock_acquired(struct lockdep_map *lock, unsigned long ip);

		#define LOCK_CONTENDED(_lock, try, lock) \
		do { \
		@@ -363,13 +368,13 @@ do { \
		lock_contended(&(_lock)->dep_map, _RET_IP_); \
		lock(_lock); \
		} \
		lock_acquired(&(_lock)->dep_map); \
		lock_acquired(&(_lock)->dep_map, _RET_IP_); \
		} while (0)

		#else /* CONFIG_LOCK_STAT */

		#define lock_contended(lockdep_map, ip) do {} while (0)
		#define lock_acquired(lockdep_map) do {} while (0)
		#define lock_acquired(lockdep_map, ip) do {} while (0)

		#define LOCK_CONTENDED(_lock, try, lock) \
		lock(_lock)

kernel/lockdep.c

+21 −12

Original line number	Diff line number	Diff line
		@@ -136,16 +136,16 @@ static inline struct lock_class hlock_class(struct held_lock hlock)
		#ifdef CONFIG_LOCK_STAT
		static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);

		static int lock_contention_point(struct lock_class *class, unsigned long ip)
		static int lock_point(unsigned long points[], unsigned long ip)
		{
		int i;

		for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
		if (class->contention_point[i] == 0) {
		class->contention_point[i] = ip;
		for (i = 0; i < LOCKSTAT_POINTS; i++) {
		if (points[i] == 0) {
		points[i] = ip;
		break;
		}
		if (class->contention_point[i] == ip)
		if (points[i] == ip)
		break;
		}

		@@ -185,6 +185,9 @@ struct lock_class_stats lock_stats(struct lock_class *class)
		for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
		stats.contention_point[i] += pcs->contention_point[i];

		for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++)
		stats.contending_point[i] += pcs->contending_point[i];

		lock_time_add(&pcs->read_waittime, &stats.read_waittime);
		lock_time_add(&pcs->write_waittime, &stats.write_waittime);

		@@ -209,6 +212,7 @@ void clear_lock_stats(struct lock_class *class)
		memset(cpu_stats, 0, sizeof(struct lock_class_stats));
		}
		memset(class->contention_point, 0, sizeof(class->contention_point));
		memset(class->contending_point, 0, sizeof(class->contending_point));
		}

		static struct lock_class_stats get_lock_stats(struct lock_class class)
		@@ -3001,7 +3005,7 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
		struct held_lock hlock, prev_hlock;
		struct lock_class_stats *stats;
		unsigned int depth;
		int i, point;
		int i, contention_point, contending_point;

		depth = curr->lockdep_depth;
		if (DEBUG_LOCKS_WARN_ON(!depth))
		@@ -3025,18 +3029,22 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
		found_it:
		hlock->waittime_stamp = sched_clock();

		point = lock_contention_point(hlock_class(hlock), ip);
		contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
		contending_point = lock_point(hlock_class(hlock)->contending_point,
		lock->ip);

		stats = get_lock_stats(hlock_class(hlock));
		if (point < ARRAY_SIZE(stats->contention_point))
		stats->contention_point[point]++;
		if (contention_point < LOCKSTAT_POINTS)
		stats->contention_point[contention_point]++;
		if (contending_point < LOCKSTAT_POINTS)
		stats->contending_point[contending_point]++;
		if (lock->cpu != smp_processor_id())
		stats->bounces[bounce_contended + !!hlock->read]++;
		put_lock_stats(stats);
		}

		static void
		__lock_acquired(struct lockdep_map *lock)
		__lock_acquired(struct lockdep_map *lock, unsigned long ip)
		{
		struct task_struct *curr = current;
		struct held_lock hlock, prev_hlock;
		@@ -3085,6 +3093,7 @@ __lock_acquired(struct lockdep_map *lock)
		put_lock_stats(stats);

		lock->cpu = cpu;
		lock->ip = ip;
		}

		void lock_contended(struct lockdep_map *lock, unsigned long ip)
		@@ -3106,7 +3115,7 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
		}
		EXPORT_SYMBOL_GPL(lock_contended);

		void lock_acquired(struct lockdep_map *lock)
		void lock_acquired(struct lockdep_map *lock, unsigned long ip)
		{
		unsigned long flags;

		@@ -3119,7 +3128,7 @@ void lock_acquired(struct lockdep_map *lock)
		raw_local_irq_save(flags);
		check_flags(flags);
		current->lockdep_recursion = 1;
		__lock_acquired(lock);
		__lock_acquired(lock, ip);
		current->lockdep_recursion = 0;
		raw_local_irq_restore(flags);
		}

kernel/lockdep_proc.c

+19 −2

Original line number	Diff line number	Diff line
		@@ -557,7 +557,7 @@ static void seq_stats(struct seq_file m, struct lock_stat_data data)
		if (stats->read_holdtime.nr)
		namelen += 2;

		for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
		for (i = 0; i < LOCKSTAT_POINTS; i++) {
		char sym[KSYM_SYMBOL_LEN];
		char ip[32];

		@@ -574,6 +574,23 @@ static void seq_stats(struct seq_file m, struct lock_stat_data data)
		stats->contention_point[i],
		ip, sym);
		}
		for (i = 0; i < LOCKSTAT_POINTS; i++) {
		char sym[KSYM_SYMBOL_LEN];
		char ip[32];

		if (class->contending_point[i] == 0)
		break;

		if (!i)
		seq_line(m, '-', 40-namelen, namelen);

		sprint_symbol(sym, class->contending_point[i]);
		snprintf(ip, sizeof(ip), "[<%p>]",
		(void *)class->contending_point[i]);
		seq_printf(m, "%40s %14lu %29s %s\n", name,
		stats->contending_point[i],
		ip, sym);
		}
		if (i) {
		seq_puts(m, "\n");
		seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
		@@ -583,7 +600,7 @@ static void seq_stats(struct seq_file m, struct lock_stat_data data)

		static void seq_header(struct seq_file *m)
		{
		seq_printf(m, "lock_stat version 0.2\n");
		seq_printf(m, "lock_stat version 0.3\n");
		seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
		seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
		"%14s %14s\n",

kernel/mutex.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -184,7 +184,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
		}

		done:
		lock_acquired(&lock->dep_map);
		lock_acquired(&lock->dep_map, ip);
		/* got the lock - rejoice! */
		mutex_remove_waiter(lock, &waiter, task_thread_info(task));
		debug_mutex_set_owner(lock, task_thread_info(task));