linux/drivers/md/bcache/util.h
Kent Overstreet c2a4f3183a bcache: Fix a writeback performance regression
Background writeback works by scanning the btree for dirty data and
adding those keys into a fixed size buffer, then for each dirty key in
the keybuf writing it to the backing device.

When read_dirty() finishes and it's time to scan for more dirty data, we
need to wait for the outstanding writeback IO to finish - they still
take up slots in the keybuf (so that foreground writes can check for
them to avoid races) - without that wait, we'll continually rescan when
we'll be able to add at most a key or two to the keybuf, and that takes
locks that starves foreground IO.  Doh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00

590 lines
15 KiB
C

#ifndef _BCACHE_UTIL_H
#define _BCACHE_UTIL_H
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/llist.h>
#include <linux/ratelimit.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
#include "closure.h"
#define PAGE_SECTORS (PAGE_SIZE / 512)
struct closure;
#ifdef CONFIG_BCACHE_EDEBUG
#define atomic_dec_bug(v) BUG_ON(atomic_dec_return(v) < 0)
#define atomic_inc_bug(v, i) BUG_ON(atomic_inc_return(v) <= i)
#else /* EDEBUG */
#define atomic_dec_bug(v) atomic_dec(v)
#define atomic_inc_bug(v, i) atomic_inc(v)
#endif
#define BITMASK(name, type, field, offset, size) \
static inline uint64_t name(const type *k) \
{ return (k->field >> offset) & ~(((uint64_t) ~0) << size); } \
\
static inline void SET_##name(type *k, uint64_t v) \
{ \
k->field &= ~(~((uint64_t) ~0 << size) << offset); \
k->field |= v << offset; \
}
#define DECLARE_HEAP(type, name) \
struct { \
size_t size, used; \
type *data; \
} name
#define init_heap(heap, _size, gfp) \
({ \
size_t _bytes; \
(heap)->used = 0; \
(heap)->size = (_size); \
_bytes = (heap)->size * sizeof(*(heap)->data); \
(heap)->data = NULL; \
if (_bytes < KMALLOC_MAX_SIZE) \
(heap)->data = kmalloc(_bytes, (gfp)); \
if ((!(heap)->data) && ((gfp) & GFP_KERNEL)) \
(heap)->data = vmalloc(_bytes); \
(heap)->data; \
})
#define free_heap(heap) \
do { \
if (is_vmalloc_addr((heap)->data)) \
vfree((heap)->data); \
else \
kfree((heap)->data); \
(heap)->data = NULL; \
} while (0)
#define heap_swap(h, i, j) swap((h)->data[i], (h)->data[j])
#define heap_sift(h, i, cmp) \
do { \
size_t _r, _j = i; \
\
for (; _j * 2 + 1 < (h)->used; _j = _r) { \
_r = _j * 2 + 1; \
if (_r + 1 < (h)->used && \
cmp((h)->data[_r], (h)->data[_r + 1])) \
_r++; \
\
if (cmp((h)->data[_r], (h)->data[_j])) \
break; \
heap_swap(h, _r, _j); \
} \
} while (0)
#define heap_sift_down(h, i, cmp) \
do { \
while (i) { \
size_t p = (i - 1) / 2; \
if (cmp((h)->data[i], (h)->data[p])) \
break; \
heap_swap(h, i, p); \
i = p; \
} \
} while (0)
#define heap_add(h, d, cmp) \
({ \
bool _r = !heap_full(h); \
if (_r) { \
size_t _i = (h)->used++; \
(h)->data[_i] = d; \
\
heap_sift_down(h, _i, cmp); \
heap_sift(h, _i, cmp); \
} \
_r; \
})
#define heap_pop(h, d, cmp) \
({ \
bool _r = (h)->used; \
if (_r) { \
(d) = (h)->data[0]; \
(h)->used--; \
heap_swap(h, 0, (h)->used); \
heap_sift(h, 0, cmp); \
} \
_r; \
})
#define heap_peek(h) ((h)->size ? (h)->data[0] : NULL)
#define heap_full(h) ((h)->used == (h)->size)
#define DECLARE_FIFO(type, name) \
struct { \
size_t front, back, size, mask; \
type *data; \
} name
#define fifo_for_each(c, fifo, iter) \
for (iter = (fifo)->front; \
c = (fifo)->data[iter], iter != (fifo)->back; \
iter = (iter + 1) & (fifo)->mask)
#define __init_fifo(fifo, gfp) \
({ \
size_t _allocated_size, _bytes; \
BUG_ON(!(fifo)->size); \
\
_allocated_size = roundup_pow_of_two((fifo)->size + 1); \
_bytes = _allocated_size * sizeof(*(fifo)->data); \
\
(fifo)->mask = _allocated_size - 1; \
(fifo)->front = (fifo)->back = 0; \
(fifo)->data = NULL; \
\
if (_bytes < KMALLOC_MAX_SIZE) \
(fifo)->data = kmalloc(_bytes, (gfp)); \
if ((!(fifo)->data) && ((gfp) & GFP_KERNEL)) \
(fifo)->data = vmalloc(_bytes); \
(fifo)->data; \
})
#define init_fifo_exact(fifo, _size, gfp) \
({ \
(fifo)->size = (_size); \
__init_fifo(fifo, gfp); \
})
#define init_fifo(fifo, _size, gfp) \
({ \
(fifo)->size = (_size); \
if ((fifo)->size > 4) \
(fifo)->size = roundup_pow_of_two((fifo)->size) - 1; \
__init_fifo(fifo, gfp); \
})
#define free_fifo(fifo) \
do { \
if (is_vmalloc_addr((fifo)->data)) \
vfree((fifo)->data); \
else \
kfree((fifo)->data); \
(fifo)->data = NULL; \
} while (0)
#define fifo_used(fifo) (((fifo)->back - (fifo)->front) & (fifo)->mask)
#define fifo_free(fifo) ((fifo)->size - fifo_used(fifo))
#define fifo_empty(fifo) (!fifo_used(fifo))
#define fifo_full(fifo) (!fifo_free(fifo))
#define fifo_front(fifo) ((fifo)->data[(fifo)->front])
#define fifo_back(fifo) \
((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
#define fifo_idx(fifo, p) (((p) - &fifo_front(fifo)) & (fifo)->mask)
#define fifo_push_back(fifo, i) \
({ \
bool _r = !fifo_full((fifo)); \
if (_r) { \
(fifo)->data[(fifo)->back++] = (i); \
(fifo)->back &= (fifo)->mask; \
} \
_r; \
})
#define fifo_pop_front(fifo, i) \
({ \
bool _r = !fifo_empty((fifo)); \
if (_r) { \
(i) = (fifo)->data[(fifo)->front++]; \
(fifo)->front &= (fifo)->mask; \
} \
_r; \
})
#define fifo_push_front(fifo, i) \
({ \
bool _r = !fifo_full((fifo)); \
if (_r) { \
--(fifo)->front; \
(fifo)->front &= (fifo)->mask; \
(fifo)->data[(fifo)->front] = (i); \
} \
_r; \
})
#define fifo_pop_back(fifo, i) \
({ \
bool _r = !fifo_empty((fifo)); \
if (_r) { \
--(fifo)->back; \
(fifo)->back &= (fifo)->mask; \
(i) = (fifo)->data[(fifo)->back] \
} \
_r; \
})
#define fifo_push(fifo, i) fifo_push_back(fifo, (i))
#define fifo_pop(fifo, i) fifo_pop_front(fifo, (i))
#define fifo_swap(l, r) \
do { \
swap((l)->front, (r)->front); \
swap((l)->back, (r)->back); \
swap((l)->size, (r)->size); \
swap((l)->mask, (r)->mask); \
swap((l)->data, (r)->data); \
} while (0)
#define fifo_move(dest, src) \
do { \
typeof(*((dest)->data)) _t; \
while (!fifo_full(dest) && \
fifo_pop(src, _t)) \
fifo_push(dest, _t); \
} while (0)
/*
* Simple array based allocator - preallocates a number of elements and you can
* never allocate more than that, also has no locking.
*
* Handy because if you know you only need a fixed number of elements you don't
* have to worry about memory allocation failure, and sometimes a mempool isn't
* what you want.
*
* We treat the free elements as entries in a singly linked list, and the
* freelist as a stack - allocating and freeing push and pop off the freelist.
*/
#define DECLARE_ARRAY_ALLOCATOR(type, name, size) \
struct { \
type *freelist; \
type data[size]; \
} name
#define array_alloc(array) \
({ \
typeof((array)->freelist) _ret = (array)->freelist; \
\
if (_ret) \
(array)->freelist = *((typeof((array)->freelist) *) _ret);\
\
_ret; \
})
#define array_free(array, ptr) \
do { \
typeof((array)->freelist) _ptr = ptr; \
\
*((typeof((array)->freelist) *) _ptr) = (array)->freelist; \
(array)->freelist = _ptr; \
} while (0)
#define array_allocator_init(array) \
do { \
typeof((array)->freelist) _i; \
\
BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *)); \
(array)->freelist = NULL; \
\
for (_i = (array)->data; \
_i < (array)->data + ARRAY_SIZE((array)->data); \
_i++) \
array_free(array, _i); \
} while (0)
#define array_freelist_empty(array) ((array)->freelist == NULL)
#define ANYSINT_MAX(t) \
((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
int bch_strtoint_h(const char *, int *);
int bch_strtouint_h(const char *, unsigned int *);
int bch_strtoll_h(const char *, long long *);
int bch_strtoull_h(const char *, unsigned long long *);
static inline int bch_strtol_h(const char *cp, long *res)
{
#if BITS_PER_LONG == 32
return bch_strtoint_h(cp, (int *) res);
#else
return bch_strtoll_h(cp, (long long *) res);
#endif
}
static inline int bch_strtoul_h(const char *cp, long *res)
{
#if BITS_PER_LONG == 32
return bch_strtouint_h(cp, (unsigned int *) res);
#else
return bch_strtoull_h(cp, (unsigned long long *) res);
#endif
}
#define strtoi_h(cp, res) \
(__builtin_types_compatible_p(typeof(*res), int) \
? bch_strtoint_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), long) \
? bch_strtol_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), long long) \
? bch_strtoll_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned int) \
? bch_strtouint_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned long) \
? bch_strtoul_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
? bch_strtoull_h(cp, (void *) res) : -EINVAL)
#define strtoul_safe(cp, var) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (!_r) \
var = _v; \
_r; \
})
#define strtoul_safe_clamp(cp, var, min, max) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (!_r) \
var = clamp_t(typeof(var), _v, min, max); \
_r; \
})
#define snprint(buf, size, var) \
snprintf(buf, size, \
__builtin_types_compatible_p(typeof(var), int) \
? "%i\n" : \
__builtin_types_compatible_p(typeof(var), unsigned) \
? "%u\n" : \
__builtin_types_compatible_p(typeof(var), long) \
? "%li\n" : \
__builtin_types_compatible_p(typeof(var), unsigned long)\
? "%lu\n" : \
__builtin_types_compatible_p(typeof(var), int64_t) \
? "%lli\n" : \
__builtin_types_compatible_p(typeof(var), uint64_t) \
? "%llu\n" : \
__builtin_types_compatible_p(typeof(var), const char *) \
? "%s\n" : "%i\n", var)
ssize_t bch_hprint(char *buf, int64_t v);
bool bch_is_zero(const char *p, size_t n);
int bch_parse_uuid(const char *s, char *uuid);
ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
size_t selected);
ssize_t bch_read_string_list(const char *buf, const char * const list[]);
struct time_stats {
/*
* all fields are in nanoseconds, averages are ewmas stored left shifted
* by 8
*/
uint64_t max_duration;
uint64_t average_duration;
uint64_t average_frequency;
uint64_t last;
};
void bch_time_stats_update(struct time_stats *stats, uint64_t time);
#define NSEC_PER_ns 1L
#define NSEC_PER_us NSEC_PER_USEC
#define NSEC_PER_ms NSEC_PER_MSEC
#define NSEC_PER_sec NSEC_PER_SEC
#define __print_time_stat(stats, name, stat, units) \
sysfs_print(name ## _ ## stat ## _ ## units, \
div_u64((stats)->stat >> 8, NSEC_PER_ ## units))
#define sysfs_print_time_stats(stats, name, \
frequency_units, \
duration_units) \
do { \
__print_time_stat(stats, name, \
average_frequency, frequency_units); \
__print_time_stat(stats, name, \
average_duration, duration_units); \
__print_time_stat(stats, name, \
max_duration, duration_units); \
\
sysfs_print(name ## _last_ ## frequency_units, (stats)->last \
? div_s64(local_clock() - (stats)->last, \
NSEC_PER_ ## frequency_units) \
: -1LL); \
} while (0)
#define sysfs_time_stats_attribute(name, \
frequency_units, \
duration_units) \
read_attribute(name ## _average_frequency_ ## frequency_units); \
read_attribute(name ## _average_duration_ ## duration_units); \
read_attribute(name ## _max_duration_ ## duration_units); \
read_attribute(name ## _last_ ## frequency_units)
#define sysfs_time_stats_attribute_list(name, \
frequency_units, \
duration_units) \
&sysfs_ ## name ## _average_frequency_ ## frequency_units, \
&sysfs_ ## name ## _average_duration_ ## duration_units, \
&sysfs_ ## name ## _max_duration_ ## duration_units, \
&sysfs_ ## name ## _last_ ## frequency_units,
#define ewma_add(ewma, val, weight, factor) \
({ \
(ewma) *= (weight) - 1; \
(ewma) += (val) << factor; \
(ewma) /= (weight); \
(ewma) >> factor; \
})
struct bch_ratelimit {
/* Next time we want to do some work, in nanoseconds */
uint64_t next;
/*
* Rate at which we want to do work, in units per nanosecond
* The units here correspond to the units passed to bch_next_delay()
*/
unsigned rate;
};
static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
{
d->next = local_clock();
}
uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);
#define __DIV_SAFE(n, d, zero) \
({ \
typeof(n) _n = (n); \
typeof(d) _d = (d); \
_d ? _n / _d : zero; \
})
#define DIV_SAFE(n, d) __DIV_SAFE(n, d, 0)
#define container_of_or_null(ptr, type, member) \
({ \
typeof(ptr) _ptr = ptr; \
_ptr ? container_of(_ptr, type, member) : NULL; \
})
#define RB_INSERT(root, new, member, cmp) \
({ \
__label__ dup; \
struct rb_node **n = &(root)->rb_node, *parent = NULL; \
typeof(new) this; \
int res, ret = -1; \
\
while (*n) { \
parent = *n; \
this = container_of(*n, typeof(*(new)), member); \
res = cmp(new, this); \
if (!res) \
goto dup; \
n = res < 0 \
? &(*n)->rb_left \
: &(*n)->rb_right; \
} \
\
rb_link_node(&(new)->member, parent, n); \
rb_insert_color(&(new)->member, root); \
ret = 0; \
dup: \
ret; \
})
#define RB_SEARCH(root, search, member, cmp) \
({ \
struct rb_node *n = (root)->rb_node; \
typeof(&(search)) this, ret = NULL; \
int res; \
\
while (n) { \
this = container_of(n, typeof(search), member); \
res = cmp(&(search), this); \
if (!res) { \
ret = this; \
break; \
} \
n = res < 0 \
? n->rb_left \
: n->rb_right; \
} \
ret; \
})
#define RB_GREATER(root, search, member, cmp) \
({ \
struct rb_node *n = (root)->rb_node; \
typeof(&(search)) this, ret = NULL; \
int res; \
\
while (n) { \
this = container_of(n, typeof(search), member); \
res = cmp(&(search), this); \
if (res < 0) { \
ret = this; \
n = n->rb_left; \
} else \
n = n->rb_right; \
} \
ret; \
})
#define RB_FIRST(root, type, member) \
container_of_or_null(rb_first(root), type, member)
#define RB_LAST(root, type, member) \
container_of_or_null(rb_last(root), type, member)
#define RB_NEXT(ptr, member) \
container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)
#define RB_PREV(ptr, member) \
container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)
/* Does linear interpolation between powers of two */
static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
{
unsigned fract = x & ~(~0 << fract_bits);
x >>= fract_bits;
x = 1 << x;
x += (x * fract) >> fract_bits;
return x;
}
void bch_bio_map(struct bio *bio, void *base);
static inline sector_t bdev_sectors(struct block_device *bdev)
{
return bdev->bd_inode->i_size >> 9;
}
#define closure_bio_submit(bio, cl, dev) \
do { \
closure_get(cl); \
bch_generic_make_request(bio, &(dev)->bio_split_hook); \
} while (0)
uint64_t bch_crc64_update(uint64_t, const void *, size_t);
uint64_t bch_crc64(const void *, size_t);
#endif /* _BCACHE_UTIL_H */