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: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>

Changed 'weight' to 'busy'.

Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Omar Sandoval 2017-01-25 14:32:13 -08:00 committed by Jens Axboe
parent 7b3938524c
commit 24af1ccfe1
2 changed files with 121 additions and 0 deletions

View File

@ -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 */

View File

@ -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);