Commit 24af1ccf authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

sbitmap: add helpers for dumping to a seq_file 



This is useful debugging information that will be used in the blk-mq
debugfs directory.

Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>

Changed 'weight' to 'busy'.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 7b393852

include/linux/sbitmap.h

+30 −0
Original line number Diff line number Diff line
@@ -258,6 +258,26 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) 


unsigned int sbitmap_weight(const struct sbitmap *sb);



/**

 * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file.

 * @sb: Bitmap to show.

 * @m: struct seq_file to write to.

 *

 * This is intended for debugging. The format may change at any time.

 */

void sbitmap_show(struct sbitmap *sb, struct seq_file *m);



/**

 * sbitmap_bitmap_show() - Write a hex dump of a &struct sbitmap to a &struct

 * seq_file.

 * @sb: Bitmap to show.

 * @m: struct seq_file to write to.

 *

 * This is intended for debugging. The output isn't guaranteed to be internally

 * consistent.

 */

void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m);



/**

 * sbitmap_queue_init_node() - Initialize a &struct sbitmap_queue on a specific

 * memory node.
@@ -370,4 +390,14 @@ static inline struct sbq_wait_state *sbq_wait_ptr(struct sbitmap_queue *sbq, 
 */

void sbitmap_queue_wake_all(struct sbitmap_queue *sbq);



/**

 * sbitmap_queue_show() - Dump &struct sbitmap_queue information to a &struct

 * seq_file.

 * @sbq: Bitmap queue to show.

 * @m: struct seq_file to write to.

 *

 * This is intended for debugging. The format may change at any time.

 */

void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m);



#endif /* __LINUX_SCALE_BITMAP_H */

lib/sbitmap.c

+91 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 


#include <linux/random.h>

#include <linux/sbitmap.h>

#include <linux/seq_file.h>



int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,

		      gfp_t flags, int node)
@@ -180,6 +181,62 @@ unsigned int sbitmap_weight(const struct sbitmap *sb) 
}

EXPORT_SYMBOL_GPL(sbitmap_weight);



void sbitmap_show(struct sbitmap *sb, struct seq_file *m)

{

	seq_printf(m, "depth=%u\n", sb->depth);

	seq_printf(m, "busy=%u\n", sbitmap_weight(sb));

	seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift);

	seq_printf(m, "map_nr=%u\n", sb->map_nr);

}

EXPORT_SYMBOL_GPL(sbitmap_show);



static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte)

{

	if ((offset & 0xf) == 0) {

		if (offset != 0)

			seq_putc(m, '\n');

		seq_printf(m, "%08x:", offset);

	}

	if ((offset & 0x1) == 0)

		seq_putc(m, ' ');

	seq_printf(m, "%02x", byte);

}



void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m)

{

	u8 byte = 0;

	unsigned int byte_bits = 0;

	unsigned int offset = 0;

	int i;



	for (i = 0; i < sb->map_nr; i++) {

		unsigned long word = READ_ONCE(sb->map[i].word);

		unsigned int word_bits = READ_ONCE(sb->map[i].depth);



		while (word_bits > 0) {

			unsigned int bits = min(8 - byte_bits, word_bits);



			byte |= (word & (BIT(bits) - 1)) << byte_bits;

			byte_bits += bits;

			if (byte_bits == 8) {

				emit_byte(m, offset, byte);

				byte = 0;

				byte_bits = 0;

				offset++;

			}

			word >>= bits;

			word_bits -= bits;

		}

	}

	if (byte_bits) {

		emit_byte(m, offset, byte);

		offset++;

	}

	if (offset)

		seq_putc(m, '\n');

}

EXPORT_SYMBOL_GPL(sbitmap_bitmap_show);



static unsigned int sbq_calc_wake_batch(unsigned int depth)

{

	unsigned int wake_batch;
@@ -377,3 +434,37 @@ void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) 
	}

}

EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all);



void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m)

{

	bool first;

	int i;



	sbitmap_show(&sbq->sb, m);



	seq_puts(m, "alloc_hint={");

	first = true;

	for_each_possible_cpu(i) {

		if (!first)

			seq_puts(m, ", ");

		first = false;

		seq_printf(m, "%u", *per_cpu_ptr(sbq->alloc_hint, i));

	}

	seq_puts(m, "}\n");



	seq_printf(m, "wake_batch=%u\n", sbq->wake_batch);

	seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index));



	seq_puts(m, "ws={\n");

	for (i = 0; i < SBQ_WAIT_QUEUES; i++) {

		struct sbq_wait_state *ws = &sbq->ws[i];



		seq_printf(m, "\t{.wait_cnt=%d, .wait=%s},\n",

			   atomic_read(&ws->wait_cnt),

			   waitqueue_active(&ws->wait) ? "active" : "inactive");

	}

	seq_puts(m, "}\n");



	seq_printf(m, "round_robin=%d\n", sbq->round_robin);

}

EXPORT_SYMBOL_GPL(sbitmap_queue_show);