1 #include <linux/errno.h>
2 #include <linux/numa.h>
3 #include <linux/slab.h>
4 #include <linux/rculist.h>
5 #include <linux/threads.h>
6 #include <linux/preempt.h>
7 #include <linux/irqflags.h>
8 #include <linux/vmalloc.h>
10 #include <linux/module.h>
11 #include <linux/device-mapper.h>
16 #define DM_MSG_PREFIX "stats"
18 static int dm_stat_need_rcu_barrier
;
21 * Using 64-bit values to avoid overflow (which is a
22 * problem that block/genhd.c's IO accounting has).
24 struct dm_stat_percpu
{
25 unsigned long long sectors
[2];
26 unsigned long long ios
[2];
27 unsigned long long merges
[2];
28 unsigned long long ticks
[2];
29 unsigned long long io_ticks
[2];
30 unsigned long long io_ticks_total
;
31 unsigned long long time_in_queue
;
32 unsigned long long *histogram
;
35 struct dm_stat_shared
{
36 atomic_t in_flight
[2];
37 unsigned long long stamp
;
38 struct dm_stat_percpu tmp
;
42 struct list_head list_entry
;
49 unsigned n_histogram_entries
;
50 unsigned long long *histogram_boundaries
;
51 const char *program_id
;
53 struct rcu_head rcu_head
;
54 size_t shared_alloc_size
;
55 size_t percpu_alloc_size
;
56 size_t histogram_alloc_size
;
57 struct dm_stat_percpu
*stat_percpu
[NR_CPUS
];
58 struct dm_stat_shared stat_shared
[0];
61 #define STAT_PRECISE_TIMESTAMPS 1
63 struct dm_stats_last_position
{
69 * A typo on the command line could possibly make the kernel run out of memory
70 * and crash. To prevent the crash we account all used memory. We fail if we
71 * exhaust 1/4 of all memory or 1/2 of vmalloc space.
73 #define DM_STATS_MEMORY_FACTOR 4
74 #define DM_STATS_VMALLOC_FACTOR 2
76 static DEFINE_SPINLOCK(shared_memory_lock
);
78 static unsigned long shared_memory_amount
;
80 static bool __check_shared_memory(size_t alloc_size
)
84 a
= shared_memory_amount
+ alloc_size
;
85 if (a
< shared_memory_amount
)
87 if (a
>> PAGE_SHIFT
> totalram_pages
/ DM_STATS_MEMORY_FACTOR
)
90 if (a
> (VMALLOC_END
- VMALLOC_START
) / DM_STATS_VMALLOC_FACTOR
)
96 static bool check_shared_memory(size_t alloc_size
)
100 spin_lock_irq(&shared_memory_lock
);
102 ret
= __check_shared_memory(alloc_size
);
104 spin_unlock_irq(&shared_memory_lock
);
109 static bool claim_shared_memory(size_t alloc_size
)
111 spin_lock_irq(&shared_memory_lock
);
113 if (!__check_shared_memory(alloc_size
)) {
114 spin_unlock_irq(&shared_memory_lock
);
118 shared_memory_amount
+= alloc_size
;
120 spin_unlock_irq(&shared_memory_lock
);
125 static void free_shared_memory(size_t alloc_size
)
129 spin_lock_irqsave(&shared_memory_lock
, flags
);
131 if (WARN_ON_ONCE(shared_memory_amount
< alloc_size
)) {
132 spin_unlock_irqrestore(&shared_memory_lock
, flags
);
133 DMCRIT("Memory usage accounting bug.");
137 shared_memory_amount
-= alloc_size
;
139 spin_unlock_irqrestore(&shared_memory_lock
, flags
);
142 static void *dm_kvzalloc(size_t alloc_size
, int node
)
146 if (!claim_shared_memory(alloc_size
))
149 p
= kvzalloc_node(alloc_size
, GFP_KERNEL
| __GFP_NOMEMALLOC
, node
);
153 free_shared_memory(alloc_size
);
158 static void dm_kvfree(void *ptr
, size_t alloc_size
)
163 free_shared_memory(alloc_size
);
168 static void dm_stat_free(struct rcu_head
*head
)
171 struct dm_stat
*s
= container_of(head
, struct dm_stat
, rcu_head
);
173 kfree(s
->histogram_boundaries
);
174 kfree(s
->program_id
);
176 for_each_possible_cpu(cpu
) {
177 dm_kvfree(s
->stat_percpu
[cpu
][0].histogram
, s
->histogram_alloc_size
);
178 dm_kvfree(s
->stat_percpu
[cpu
], s
->percpu_alloc_size
);
180 dm_kvfree(s
->stat_shared
[0].tmp
.histogram
, s
->histogram_alloc_size
);
181 dm_kvfree(s
, s
->shared_alloc_size
);
184 static int dm_stat_in_flight(struct dm_stat_shared
*shared
)
186 return atomic_read(&shared
->in_flight
[READ
]) +
187 atomic_read(&shared
->in_flight
[WRITE
]);
190 void dm_stats_init(struct dm_stats
*stats
)
193 struct dm_stats_last_position
*last
;
195 mutex_init(&stats
->mutex
);
196 INIT_LIST_HEAD(&stats
->list
);
197 stats
->last
= alloc_percpu(struct dm_stats_last_position
);
198 for_each_possible_cpu(cpu
) {
199 last
= per_cpu_ptr(stats
->last
, cpu
);
200 last
->last_sector
= (sector_t
)ULLONG_MAX
;
201 last
->last_rw
= UINT_MAX
;
205 void dm_stats_cleanup(struct dm_stats
*stats
)
209 struct dm_stat_shared
*shared
;
211 while (!list_empty(&stats
->list
)) {
212 s
= container_of(stats
->list
.next
, struct dm_stat
, list_entry
);
213 list_del(&s
->list_entry
);
214 for (ni
= 0; ni
< s
->n_entries
; ni
++) {
215 shared
= &s
->stat_shared
[ni
];
216 if (WARN_ON(dm_stat_in_flight(shared
))) {
217 DMCRIT("leaked in-flight counter at index %lu "
218 "(start %llu, end %llu, step %llu): reads %d, writes %d",
220 (unsigned long long)s
->start
,
221 (unsigned long long)s
->end
,
222 (unsigned long long)s
->step
,
223 atomic_read(&shared
->in_flight
[READ
]),
224 atomic_read(&shared
->in_flight
[WRITE
]));
227 dm_stat_free(&s
->rcu_head
);
229 free_percpu(stats
->last
);
232 static int dm_stats_create(struct dm_stats
*stats
, sector_t start
, sector_t end
,
233 sector_t step
, unsigned stat_flags
,
234 unsigned n_histogram_entries
,
235 unsigned long long *histogram_boundaries
,
236 const char *program_id
, const char *aux_data
,
237 void (*suspend_callback
)(struct mapped_device
*),
238 void (*resume_callback
)(struct mapped_device
*),
239 struct mapped_device
*md
)
242 struct dm_stat
*s
, *tmp_s
;
245 size_t shared_alloc_size
;
246 size_t percpu_alloc_size
;
247 size_t histogram_alloc_size
;
248 struct dm_stat_percpu
*p
;
253 if (end
< start
|| !step
)
256 n_entries
= end
- start
;
257 if (dm_sector_div64(n_entries
, step
))
260 if (n_entries
!= (size_t)n_entries
|| !(size_t)(n_entries
+ 1))
263 shared_alloc_size
= sizeof(struct dm_stat
) + (size_t)n_entries
* sizeof(struct dm_stat_shared
);
264 if ((shared_alloc_size
- sizeof(struct dm_stat
)) / sizeof(struct dm_stat_shared
) != n_entries
)
267 percpu_alloc_size
= (size_t)n_entries
* sizeof(struct dm_stat_percpu
);
268 if (percpu_alloc_size
/ sizeof(struct dm_stat_percpu
) != n_entries
)
271 histogram_alloc_size
= (n_histogram_entries
+ 1) * (size_t)n_entries
* sizeof(unsigned long long);
272 if (histogram_alloc_size
/ (n_histogram_entries
+ 1) != (size_t)n_entries
* sizeof(unsigned long long))
275 if (!check_shared_memory(shared_alloc_size
+ histogram_alloc_size
+
276 num_possible_cpus() * (percpu_alloc_size
+ histogram_alloc_size
)))
279 s
= dm_kvzalloc(shared_alloc_size
, NUMA_NO_NODE
);
283 s
->stat_flags
= stat_flags
;
284 s
->n_entries
= n_entries
;
288 s
->shared_alloc_size
= shared_alloc_size
;
289 s
->percpu_alloc_size
= percpu_alloc_size
;
290 s
->histogram_alloc_size
= histogram_alloc_size
;
292 s
->n_histogram_entries
= n_histogram_entries
;
293 s
->histogram_boundaries
= kmemdup(histogram_boundaries
,
294 s
->n_histogram_entries
* sizeof(unsigned long long), GFP_KERNEL
);
295 if (!s
->histogram_boundaries
) {
300 s
->program_id
= kstrdup(program_id
, GFP_KERNEL
);
301 if (!s
->program_id
) {
305 s
->aux_data
= kstrdup(aux_data
, GFP_KERNEL
);
311 for (ni
= 0; ni
< n_entries
; ni
++) {
312 atomic_set(&s
->stat_shared
[ni
].in_flight
[READ
], 0);
313 atomic_set(&s
->stat_shared
[ni
].in_flight
[WRITE
], 0);
316 if (s
->n_histogram_entries
) {
317 unsigned long long *hi
;
318 hi
= dm_kvzalloc(s
->histogram_alloc_size
, NUMA_NO_NODE
);
323 for (ni
= 0; ni
< n_entries
; ni
++) {
324 s
->stat_shared
[ni
].tmp
.histogram
= hi
;
325 hi
+= s
->n_histogram_entries
+ 1;
329 for_each_possible_cpu(cpu
) {
330 p
= dm_kvzalloc(percpu_alloc_size
, cpu_to_node(cpu
));
335 s
->stat_percpu
[cpu
] = p
;
336 if (s
->n_histogram_entries
) {
337 unsigned long long *hi
;
338 hi
= dm_kvzalloc(s
->histogram_alloc_size
, cpu_to_node(cpu
));
343 for (ni
= 0; ni
< n_entries
; ni
++) {
344 p
[ni
].histogram
= hi
;
345 hi
+= s
->n_histogram_entries
+ 1;
351 * Suspend/resume to make sure there is no i/o in flight,
352 * so that newly created statistics will be exact.
354 * (note: we couldn't suspend earlier because we must not
355 * allocate memory while suspended)
357 suspend_callback(md
);
359 mutex_lock(&stats
->mutex
);
361 list_for_each(l
, &stats
->list
) {
362 tmp_s
= container_of(l
, struct dm_stat
, list_entry
);
363 if (WARN_ON(tmp_s
->id
< s
->id
)) {
365 goto out_unlock_resume
;
367 if (tmp_s
->id
> s
->id
)
369 if (unlikely(s
->id
== INT_MAX
)) {
371 goto out_unlock_resume
;
376 list_add_tail_rcu(&s
->list_entry
, l
);
377 mutex_unlock(&stats
->mutex
);
384 mutex_unlock(&stats
->mutex
);
387 dm_stat_free(&s
->rcu_head
);
391 static struct dm_stat
*__dm_stats_find(struct dm_stats
*stats
, int id
)
395 list_for_each_entry(s
, &stats
->list
, list_entry
) {
405 static int dm_stats_delete(struct dm_stats
*stats
, int id
)
410 mutex_lock(&stats
->mutex
);
412 s
= __dm_stats_find(stats
, id
);
414 mutex_unlock(&stats
->mutex
);
418 list_del_rcu(&s
->list_entry
);
419 mutex_unlock(&stats
->mutex
);
422 * vfree can't be called from RCU callback
424 for_each_possible_cpu(cpu
)
425 if (is_vmalloc_addr(s
->stat_percpu
) ||
426 is_vmalloc_addr(s
->stat_percpu
[cpu
][0].histogram
))
428 if (is_vmalloc_addr(s
) ||
429 is_vmalloc_addr(s
->stat_shared
[0].tmp
.histogram
)) {
431 synchronize_rcu_expedited();
432 dm_stat_free(&s
->rcu_head
);
434 ACCESS_ONCE(dm_stat_need_rcu_barrier
) = 1;
435 call_rcu(&s
->rcu_head
, dm_stat_free
);
440 static int dm_stats_list(struct dm_stats
*stats
, const char *program
,
441 char *result
, unsigned maxlen
)
449 * <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
452 mutex_lock(&stats
->mutex
);
453 list_for_each_entry(s
, &stats
->list
, list_entry
) {
454 if (!program
|| !strcmp(program
, s
->program_id
)) {
455 len
= s
->end
- s
->start
;
456 DMEMIT("%d: %llu+%llu %llu %s %s", s
->id
,
457 (unsigned long long)s
->start
,
458 (unsigned long long)len
,
459 (unsigned long long)s
->step
,
462 if (s
->stat_flags
& STAT_PRECISE_TIMESTAMPS
)
463 DMEMIT(" precise_timestamps");
464 if (s
->n_histogram_entries
) {
466 DMEMIT(" histogram:");
467 for (i
= 0; i
< s
->n_histogram_entries
; i
++) {
470 DMEMIT("%llu", s
->histogram_boundaries
[i
]);
476 mutex_unlock(&stats
->mutex
);
481 static void dm_stat_round(struct dm_stat
*s
, struct dm_stat_shared
*shared
,
482 struct dm_stat_percpu
*p
)
485 * This is racy, but so is part_round_stats_single.
487 unsigned long long now
, difference
;
488 unsigned in_flight_read
, in_flight_write
;
490 if (likely(!(s
->stat_flags
& STAT_PRECISE_TIMESTAMPS
)))
493 now
= ktime_to_ns(ktime_get());
495 difference
= now
- shared
->stamp
;
499 in_flight_read
= (unsigned)atomic_read(&shared
->in_flight
[READ
]);
500 in_flight_write
= (unsigned)atomic_read(&shared
->in_flight
[WRITE
]);
502 p
->io_ticks
[READ
] += difference
;
504 p
->io_ticks
[WRITE
] += difference
;
505 if (in_flight_read
+ in_flight_write
) {
506 p
->io_ticks_total
+= difference
;
507 p
->time_in_queue
+= (in_flight_read
+ in_flight_write
) * difference
;
512 static void dm_stat_for_entry(struct dm_stat
*s
, size_t entry
,
513 int idx
, sector_t len
,
514 struct dm_stats_aux
*stats_aux
, bool end
,
515 unsigned long duration_jiffies
)
517 struct dm_stat_shared
*shared
= &s
->stat_shared
[entry
];
518 struct dm_stat_percpu
*p
;
521 * For strict correctness we should use local_irq_save/restore
522 * instead of preempt_disable/enable.
524 * preempt_disable/enable is racy if the driver finishes bios
525 * from non-interrupt context as well as from interrupt context
526 * or from more different interrupts.
528 * On 64-bit architectures the race only results in not counting some
529 * events, so it is acceptable. On 32-bit architectures the race could
530 * cause the counter going off by 2^32, so we need to do proper locking
533 * part_stat_lock()/part_stat_unlock() have this race too.
535 #if BITS_PER_LONG == 32
537 local_irq_save(flags
);
541 p
= &s
->stat_percpu
[smp_processor_id()][entry
];
544 dm_stat_round(s
, shared
, p
);
545 atomic_inc(&shared
->in_flight
[idx
]);
547 unsigned long long duration
;
548 dm_stat_round(s
, shared
, p
);
549 atomic_dec(&shared
->in_flight
[idx
]);
550 p
->sectors
[idx
] += len
;
552 p
->merges
[idx
] += stats_aux
->merged
;
553 if (!(s
->stat_flags
& STAT_PRECISE_TIMESTAMPS
)) {
554 p
->ticks
[idx
] += duration_jiffies
;
555 duration
= jiffies_to_msecs(duration_jiffies
);
557 p
->ticks
[idx
] += stats_aux
->duration_ns
;
558 duration
= stats_aux
->duration_ns
;
560 if (s
->n_histogram_entries
) {
561 unsigned lo
= 0, hi
= s
->n_histogram_entries
+ 1;
562 while (lo
+ 1 < hi
) {
563 unsigned mid
= (lo
+ hi
) / 2;
564 if (s
->histogram_boundaries
[mid
- 1] > duration
) {
575 #if BITS_PER_LONG == 32
576 local_irq_restore(flags
);
582 static void __dm_stat_bio(struct dm_stat
*s
, int bi_rw
,
583 sector_t bi_sector
, sector_t end_sector
,
584 bool end
, unsigned long duration_jiffies
,
585 struct dm_stats_aux
*stats_aux
)
587 sector_t rel_sector
, offset
, todo
, fragment_len
;
590 if (end_sector
<= s
->start
|| bi_sector
>= s
->end
)
592 if (unlikely(bi_sector
< s
->start
)) {
594 todo
= end_sector
- s
->start
;
596 rel_sector
= bi_sector
- s
->start
;
597 todo
= end_sector
- bi_sector
;
599 if (unlikely(end_sector
> s
->end
))
600 todo
-= (end_sector
- s
->end
);
602 offset
= dm_sector_div64(rel_sector
, s
->step
);
605 if (WARN_ON_ONCE(entry
>= s
->n_entries
)) {
606 DMCRIT("Invalid area access in region id %d", s
->id
);
610 if (fragment_len
> s
->step
- offset
)
611 fragment_len
= s
->step
- offset
;
612 dm_stat_for_entry(s
, entry
, bi_rw
, fragment_len
,
613 stats_aux
, end
, duration_jiffies
);
614 todo
-= fragment_len
;
617 } while (unlikely(todo
!= 0));
620 void dm_stats_account_io(struct dm_stats
*stats
, unsigned long bi_rw
,
621 sector_t bi_sector
, unsigned bi_sectors
, bool end
,
622 unsigned long duration_jiffies
,
623 struct dm_stats_aux
*stats_aux
)
627 struct dm_stats_last_position
*last
;
628 bool got_precise_time
;
630 if (unlikely(!bi_sectors
))
633 end_sector
= bi_sector
+ bi_sectors
;
637 * A race condition can at worst result in the merged flag being
638 * misrepresented, so we don't have to disable preemption here.
640 last
= raw_cpu_ptr(stats
->last
);
642 (bi_sector
== (ACCESS_ONCE(last
->last_sector
) &&
644 (ACCESS_ONCE(last
->last_rw
) == WRITE
))
646 ACCESS_ONCE(last
->last_sector
) = end_sector
;
647 ACCESS_ONCE(last
->last_rw
) = bi_rw
;
652 got_precise_time
= false;
653 list_for_each_entry_rcu(s
, &stats
->list
, list_entry
) {
654 if (s
->stat_flags
& STAT_PRECISE_TIMESTAMPS
&& !got_precise_time
) {
656 stats_aux
->duration_ns
= ktime_to_ns(ktime_get());
658 stats_aux
->duration_ns
= ktime_to_ns(ktime_get()) - stats_aux
->duration_ns
;
659 got_precise_time
= true;
661 __dm_stat_bio(s
, bi_rw
, bi_sector
, end_sector
, end
, duration_jiffies
, stats_aux
);
667 static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared
*shared
,
668 struct dm_stat
*s
, size_t x
)
671 struct dm_stat_percpu
*p
;
674 p
= &s
->stat_percpu
[smp_processor_id()][x
];
675 dm_stat_round(s
, shared
, p
);
678 shared
->tmp
.sectors
[READ
] = 0;
679 shared
->tmp
.sectors
[WRITE
] = 0;
680 shared
->tmp
.ios
[READ
] = 0;
681 shared
->tmp
.ios
[WRITE
] = 0;
682 shared
->tmp
.merges
[READ
] = 0;
683 shared
->tmp
.merges
[WRITE
] = 0;
684 shared
->tmp
.ticks
[READ
] = 0;
685 shared
->tmp
.ticks
[WRITE
] = 0;
686 shared
->tmp
.io_ticks
[READ
] = 0;
687 shared
->tmp
.io_ticks
[WRITE
] = 0;
688 shared
->tmp
.io_ticks_total
= 0;
689 shared
->tmp
.time_in_queue
= 0;
691 if (s
->n_histogram_entries
)
692 memset(shared
->tmp
.histogram
, 0, (s
->n_histogram_entries
+ 1) * sizeof(unsigned long long));
694 for_each_possible_cpu(cpu
) {
695 p
= &s
->stat_percpu
[cpu
][x
];
696 shared
->tmp
.sectors
[READ
] += ACCESS_ONCE(p
->sectors
[READ
]);
697 shared
->tmp
.sectors
[WRITE
] += ACCESS_ONCE(p
->sectors
[WRITE
]);
698 shared
->tmp
.ios
[READ
] += ACCESS_ONCE(p
->ios
[READ
]);
699 shared
->tmp
.ios
[WRITE
] += ACCESS_ONCE(p
->ios
[WRITE
]);
700 shared
->tmp
.merges
[READ
] += ACCESS_ONCE(p
->merges
[READ
]);
701 shared
->tmp
.merges
[WRITE
] += ACCESS_ONCE(p
->merges
[WRITE
]);
702 shared
->tmp
.ticks
[READ
] += ACCESS_ONCE(p
->ticks
[READ
]);
703 shared
->tmp
.ticks
[WRITE
] += ACCESS_ONCE(p
->ticks
[WRITE
]);
704 shared
->tmp
.io_ticks
[READ
] += ACCESS_ONCE(p
->io_ticks
[READ
]);
705 shared
->tmp
.io_ticks
[WRITE
] += ACCESS_ONCE(p
->io_ticks
[WRITE
]);
706 shared
->tmp
.io_ticks_total
+= ACCESS_ONCE(p
->io_ticks_total
);
707 shared
->tmp
.time_in_queue
+= ACCESS_ONCE(p
->time_in_queue
);
708 if (s
->n_histogram_entries
) {
710 for (i
= 0; i
< s
->n_histogram_entries
+ 1; i
++)
711 shared
->tmp
.histogram
[i
] += ACCESS_ONCE(p
->histogram
[i
]);
716 static void __dm_stat_clear(struct dm_stat
*s
, size_t idx_start
, size_t idx_end
,
717 bool init_tmp_percpu_totals
)
720 struct dm_stat_shared
*shared
;
721 struct dm_stat_percpu
*p
;
723 for (x
= idx_start
; x
< idx_end
; x
++) {
724 shared
= &s
->stat_shared
[x
];
725 if (init_tmp_percpu_totals
)
726 __dm_stat_init_temporary_percpu_totals(shared
, s
, x
);
728 p
= &s
->stat_percpu
[smp_processor_id()][x
];
729 p
->sectors
[READ
] -= shared
->tmp
.sectors
[READ
];
730 p
->sectors
[WRITE
] -= shared
->tmp
.sectors
[WRITE
];
731 p
->ios
[READ
] -= shared
->tmp
.ios
[READ
];
732 p
->ios
[WRITE
] -= shared
->tmp
.ios
[WRITE
];
733 p
->merges
[READ
] -= shared
->tmp
.merges
[READ
];
734 p
->merges
[WRITE
] -= shared
->tmp
.merges
[WRITE
];
735 p
->ticks
[READ
] -= shared
->tmp
.ticks
[READ
];
736 p
->ticks
[WRITE
] -= shared
->tmp
.ticks
[WRITE
];
737 p
->io_ticks
[READ
] -= shared
->tmp
.io_ticks
[READ
];
738 p
->io_ticks
[WRITE
] -= shared
->tmp
.io_ticks
[WRITE
];
739 p
->io_ticks_total
-= shared
->tmp
.io_ticks_total
;
740 p
->time_in_queue
-= shared
->tmp
.time_in_queue
;
742 if (s
->n_histogram_entries
) {
744 for (i
= 0; i
< s
->n_histogram_entries
+ 1; i
++) {
746 p
= &s
->stat_percpu
[smp_processor_id()][x
];
747 p
->histogram
[i
] -= shared
->tmp
.histogram
[i
];
754 static int dm_stats_clear(struct dm_stats
*stats
, int id
)
758 mutex_lock(&stats
->mutex
);
760 s
= __dm_stats_find(stats
, id
);
762 mutex_unlock(&stats
->mutex
);
766 __dm_stat_clear(s
, 0, s
->n_entries
, true);
768 mutex_unlock(&stats
->mutex
);
774 * This is like jiffies_to_msec, but works for 64-bit values.
776 static unsigned long long dm_jiffies_to_msec64(struct dm_stat
*s
, unsigned long long j
)
778 unsigned long long result
;
781 if (s
->stat_flags
& STAT_PRECISE_TIMESTAMPS
)
786 result
= jiffies_to_msecs(j
& 0x3fffff);
788 mult
= jiffies_to_msecs(1 << 22);
789 result
+= (unsigned long long)mult
* (unsigned long long)jiffies_to_msecs((j
>> 22) & 0x3fffff);
792 result
+= (unsigned long long)mult
* (unsigned long long)mult
* (unsigned long long)jiffies_to_msecs(j
>> 44);
797 static int dm_stats_print(struct dm_stats
*stats
, int id
,
798 size_t idx_start
, size_t idx_len
,
799 bool clear
, char *result
, unsigned maxlen
)
804 sector_t start
, end
, step
;
806 struct dm_stat_shared
*shared
;
810 * <start_sector>+<length> counters
813 mutex_lock(&stats
->mutex
);
815 s
= __dm_stats_find(stats
, id
);
817 mutex_unlock(&stats
->mutex
);
821 idx_end
= idx_start
+ idx_len
;
822 if (idx_end
< idx_start
||
823 idx_end
> s
->n_entries
)
824 idx_end
= s
->n_entries
;
826 if (idx_start
> idx_end
)
830 start
= s
->start
+ (step
* idx_start
);
832 for (x
= idx_start
; x
< idx_end
; x
++, start
= end
) {
833 shared
= &s
->stat_shared
[x
];
835 if (unlikely(end
> s
->end
))
838 __dm_stat_init_temporary_percpu_totals(shared
, s
, x
);
840 DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu",
841 (unsigned long long)start
,
842 (unsigned long long)step
,
843 shared
->tmp
.ios
[READ
],
844 shared
->tmp
.merges
[READ
],
845 shared
->tmp
.sectors
[READ
],
846 dm_jiffies_to_msec64(s
, shared
->tmp
.ticks
[READ
]),
847 shared
->tmp
.ios
[WRITE
],
848 shared
->tmp
.merges
[WRITE
],
849 shared
->tmp
.sectors
[WRITE
],
850 dm_jiffies_to_msec64(s
, shared
->tmp
.ticks
[WRITE
]),
851 dm_stat_in_flight(shared
),
852 dm_jiffies_to_msec64(s
, shared
->tmp
.io_ticks_total
),
853 dm_jiffies_to_msec64(s
, shared
->tmp
.time_in_queue
),
854 dm_jiffies_to_msec64(s
, shared
->tmp
.io_ticks
[READ
]),
855 dm_jiffies_to_msec64(s
, shared
->tmp
.io_ticks
[WRITE
]));
856 if (s
->n_histogram_entries
) {
858 for (i
= 0; i
< s
->n_histogram_entries
+ 1; i
++) {
859 DMEMIT("%s%llu", !i
? " " : ":", shared
->tmp
.histogram
[i
]);
864 if (unlikely(sz
+ 1 >= maxlen
))
865 goto buffer_overflow
;
869 __dm_stat_clear(s
, idx_start
, idx_end
, false);
872 mutex_unlock(&stats
->mutex
);
877 static int dm_stats_set_aux(struct dm_stats
*stats
, int id
, const char *aux_data
)
880 const char *new_aux_data
;
882 mutex_lock(&stats
->mutex
);
884 s
= __dm_stats_find(stats
, id
);
886 mutex_unlock(&stats
->mutex
);
890 new_aux_data
= kstrdup(aux_data
, GFP_KERNEL
);
892 mutex_unlock(&stats
->mutex
);
897 s
->aux_data
= new_aux_data
;
899 mutex_unlock(&stats
->mutex
);
904 static int parse_histogram(const char *h
, unsigned *n_histogram_entries
,
905 unsigned long long **histogram_boundaries
)
909 unsigned long long last
;
911 *n_histogram_entries
= 1;
914 (*n_histogram_entries
)++;
916 *histogram_boundaries
= kmalloc(*n_histogram_entries
* sizeof(unsigned long long), GFP_KERNEL
);
917 if (!*histogram_boundaries
)
923 unsigned long long hi
;
926 s
= sscanf(h
, "%llu%c", &hi
, &ch
);
927 if (!s
|| (s
== 2 && ch
!= ','))
932 (*histogram_boundaries
)[n
] = hi
;
935 h
= strchr(h
, ',') + 1;
940 static int message_stats_create(struct mapped_device
*md
,
941 unsigned argc
, char **argv
,
942 char *result
, unsigned maxlen
)
947 unsigned long long start
, end
, len
, step
;
949 const char *program_id
, *aux_data
;
950 unsigned stat_flags
= 0;
952 unsigned n_histogram_entries
= 0;
953 unsigned long long *histogram_boundaries
= NULL
;
955 struct dm_arg_set as
, as_backup
;
957 unsigned feature_args
;
961 * <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]]
969 dm_consume_args(&as
, 1);
971 a
= dm_shift_arg(&as
);
972 if (!strcmp(a
, "-")) {
974 len
= dm_get_size(md
);
977 } else if (sscanf(a
, "%llu+%llu%c", &start
, &len
, &dummy
) != 2 ||
978 start
!= (sector_t
)start
|| len
!= (sector_t
)len
)
985 a
= dm_shift_arg(&as
);
986 if (sscanf(a
, "/%u%c", &divisor
, &dummy
) == 1) {
990 if (do_div(step
, divisor
))
994 } else if (sscanf(a
, "%llu%c", &step
, &dummy
) != 1 ||
995 step
!= (sector_t
)step
|| !step
)
999 a
= dm_shift_arg(&as
);
1000 if (a
&& sscanf(a
, "%u%c", &feature_args
, &dummy
) == 1) {
1001 while (feature_args
--) {
1002 a
= dm_shift_arg(&as
);
1005 if (!strcasecmp(a
, "precise_timestamps"))
1006 stat_flags
|= STAT_PRECISE_TIMESTAMPS
;
1007 else if (!strncasecmp(a
, "histogram:", 10)) {
1008 if (n_histogram_entries
)
1010 if ((r
= parse_histogram(a
+ 10, &n_histogram_entries
, &histogram_boundaries
)))
1022 a
= dm_shift_arg(&as
);
1026 a
= dm_shift_arg(&as
);
1034 * If a buffer overflow happens after we created the region,
1035 * it's too late (the userspace would retry with a larger
1036 * buffer, but the region id that caused the overflow is already
1037 * leaked). So we must detect buffer overflow in advance.
1039 snprintf(result
, maxlen
, "%d", INT_MAX
);
1040 if (dm_message_test_buffer_overflow(result
, maxlen
)) {
1045 id
= dm_stats_create(dm_get_stats(md
), start
, end
, step
, stat_flags
,
1046 n_histogram_entries
, histogram_boundaries
, program_id
, aux_data
,
1047 dm_internal_suspend_fast
, dm_internal_resume_fast
, md
);
1053 snprintf(result
, maxlen
, "%d", id
);
1061 kfree(histogram_boundaries
);
1065 static int message_stats_delete(struct mapped_device
*md
,
1066 unsigned argc
, char **argv
)
1074 if (sscanf(argv
[1], "%d%c", &id
, &dummy
) != 1 || id
< 0)
1077 return dm_stats_delete(dm_get_stats(md
), id
);
1080 static int message_stats_clear(struct mapped_device
*md
,
1081 unsigned argc
, char **argv
)
1089 if (sscanf(argv
[1], "%d%c", &id
, &dummy
) != 1 || id
< 0)
1092 return dm_stats_clear(dm_get_stats(md
), id
);
1095 static int message_stats_list(struct mapped_device
*md
,
1096 unsigned argc
, char **argv
,
1097 char *result
, unsigned maxlen
)
1100 const char *program
= NULL
;
1102 if (argc
< 1 || argc
> 2)
1106 program
= kstrdup(argv
[1], GFP_KERNEL
);
1111 r
= dm_stats_list(dm_get_stats(md
), program
, result
, maxlen
);
1118 static int message_stats_print(struct mapped_device
*md
,
1119 unsigned argc
, char **argv
, bool clear
,
1120 char *result
, unsigned maxlen
)
1124 unsigned long idx_start
= 0, idx_len
= ULONG_MAX
;
1126 if (argc
!= 2 && argc
!= 4)
1129 if (sscanf(argv
[1], "%d%c", &id
, &dummy
) != 1 || id
< 0)
1133 if (strcmp(argv
[2], "-") &&
1134 sscanf(argv
[2], "%lu%c", &idx_start
, &dummy
) != 1)
1136 if (strcmp(argv
[3], "-") &&
1137 sscanf(argv
[3], "%lu%c", &idx_len
, &dummy
) != 1)
1141 return dm_stats_print(dm_get_stats(md
), id
, idx_start
, idx_len
, clear
,
1145 static int message_stats_set_aux(struct mapped_device
*md
,
1146 unsigned argc
, char **argv
)
1154 if (sscanf(argv
[1], "%d%c", &id
, &dummy
) != 1 || id
< 0)
1157 return dm_stats_set_aux(dm_get_stats(md
), id
, argv
[2]);
1160 int dm_stats_message(struct mapped_device
*md
, unsigned argc
, char **argv
,
1161 char *result
, unsigned maxlen
)
1165 /* All messages here must start with '@' */
1166 if (!strcasecmp(argv
[0], "@stats_create"))
1167 r
= message_stats_create(md
, argc
, argv
, result
, maxlen
);
1168 else if (!strcasecmp(argv
[0], "@stats_delete"))
1169 r
= message_stats_delete(md
, argc
, argv
);
1170 else if (!strcasecmp(argv
[0], "@stats_clear"))
1171 r
= message_stats_clear(md
, argc
, argv
);
1172 else if (!strcasecmp(argv
[0], "@stats_list"))
1173 r
= message_stats_list(md
, argc
, argv
, result
, maxlen
);
1174 else if (!strcasecmp(argv
[0], "@stats_print"))
1175 r
= message_stats_print(md
, argc
, argv
, false, result
, maxlen
);
1176 else if (!strcasecmp(argv
[0], "@stats_print_clear"))
1177 r
= message_stats_print(md
, argc
, argv
, true, result
, maxlen
);
1178 else if (!strcasecmp(argv
[0], "@stats_set_aux"))
1179 r
= message_stats_set_aux(md
, argc
, argv
);
1181 return 2; /* this wasn't a stats message */
1184 DMWARN("Invalid parameters for message %s", argv
[0]);
1189 int __init
dm_statistics_init(void)
1191 shared_memory_amount
= 0;
1192 dm_stat_need_rcu_barrier
= 0;
1196 void dm_statistics_exit(void)
1198 if (dm_stat_need_rcu_barrier
)
1200 if (WARN_ON(shared_memory_amount
))
1201 DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount
);
1204 module_param_named(stats_current_allocated_bytes
, shared_memory_amount
, ulong
, S_IRUGO
);
1205 MODULE_PARM_DESC(stats_current_allocated_bytes
, "Memory currently used by statistics");