bcachefs: remove heap-related macros and switch to generic min_heap

Drop the heap-related macros from bcachefs and replacing them with the
generic min_heap implementation from include/linux.  By doing so, code
readability is improved by using functions instead of macros.  Moreover,
the min_heap implementation in include/linux adopts a bottom-up variation
compared to the textbook version currently used in bcachefs.  This
bottom-up variation allows for approximately 50% reduction in the number
of comparison operations during heap siftdown, without changing the number
of swaps, thus making it more efficient.

[visitorckw@gmail.com: fix missing assignment of minimum element]
  Link: https://lkml.kernel.org/r/20240602174828.1955320-1-visitorckw@gmail.com
Link: https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
Link: https://lkml.kernel.org/r/20240524152958.919343-17-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kuan-Wei Chiu 2024-05-24 23:29:58 +08:00 committed by Andrew Morton
parent 866898efbb
commit 1fcce6b8a7
5 changed files with 91 additions and 156 deletions

View File

@ -6,16 +6,29 @@
#include <linux/kthread.h>
#include <linux/preempt.h>
static inline long io_timer_cmp(io_timer_heap *h,
struct io_timer *l,
struct io_timer *r)
static inline bool io_timer_cmp(const void *l, const void *r, void __always_unused *args)
{
return l->expire - r->expire;
struct io_timer **_l = (struct io_timer **)l;
struct io_timer **_r = (struct io_timer **)r;
return (*_l)->expire < (*_r)->expire;
}
static inline void io_timer_swp(void *l, void *r, void __always_unused *args)
{
struct io_timer **_l = (struct io_timer **)l;
struct io_timer **_r = (struct io_timer **)r;
swap(*_l, *_r);
}
void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer)
{
size_t i;
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
spin_lock(&clock->timer_lock);
@ -26,11 +39,11 @@ void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer)
return;
}
for (i = 0; i < clock->timers.used; i++)
for (i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[i] == timer)
goto out;
BUG_ON(!heap_add(&clock->timers, timer, io_timer_cmp, NULL));
BUG_ON(!min_heap_push(&clock->timers, &timer, &callbacks, NULL));
out:
spin_unlock(&clock->timer_lock);
}
@ -38,12 +51,16 @@ out:
void bch2_io_timer_del(struct io_clock *clock, struct io_timer *timer)
{
size_t i;
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
spin_lock(&clock->timer_lock);
for (i = 0; i < clock->timers.used; i++)
for (i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[i] == timer) {
heap_del(&clock->timers, i, io_timer_cmp, NULL);
min_heap_del(&clock->timers, i, &callbacks, NULL);
break;
}
@ -131,12 +148,18 @@ static struct io_timer *get_expired_timer(struct io_clock *clock,
unsigned long now)
{
struct io_timer *ret = NULL;
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
spin_lock(&clock->timer_lock);
if (clock->timers.used &&
time_after_eq(now, clock->timers.data[0]->expire))
heap_pop(&clock->timers, ret, io_timer_cmp, NULL);
if (clock->timers.nr &&
time_after_eq(now, clock->timers.data[0]->expire)) {
ret = *min_heap_peek(&clock->timers);
min_heap_pop(&clock->timers, &callbacks, NULL);
}
spin_unlock(&clock->timer_lock);
@ -161,7 +184,7 @@ void bch2_io_timers_to_text(struct printbuf *out, struct io_clock *clock)
spin_lock(&clock->timer_lock);
now = atomic64_read(&clock->now);
for (i = 0; i < clock->timers.used; i++)
for (i = 0; i < clock->timers.nr; i++)
prt_printf(out, "%ps:\t%li\n",
clock->timers.data[i]->fn,
clock->timers.data[i]->expire - now);

View File

@ -23,7 +23,7 @@ struct io_timer {
/* Amount to buffer up on a percpu counter */
#define IO_CLOCK_PCPU_SECTORS 128
typedef HEAP(struct io_timer *) io_timer_heap;
typedef DEFINE_MIN_HEAP(struct io_timer *, io_timer_heap) io_timer_heap;
struct io_clock {
atomic64_t now;

View File

@ -910,8 +910,8 @@ static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
mutex_lock(&c->ec_stripes_heap_lock);
if (n.size > h->size) {
memcpy(n.data, h->data, h->used * sizeof(h->data[0]));
n.used = h->used;
memcpy(n.data, h->data, h->nr * sizeof(h->data[0]));
n.nr = h->nr;
swap(*h, n);
}
mutex_unlock(&c->ec_stripes_heap_lock);
@ -1002,7 +1002,7 @@ static u64 stripe_idx_to_delete(struct bch_fs *c)
lockdep_assert_held(&c->ec_stripes_heap_lock);
if (h->used &&
if (h->nr &&
h->data[0].blocks_nonempty == 0 &&
!bch2_stripe_is_open(c, h->data[0].idx))
return h->data[0].idx;
@ -1010,14 +1010,6 @@ static u64 stripe_idx_to_delete(struct bch_fs *c)
return 0;
}
static inline int ec_stripes_heap_cmp(ec_stripes_heap *h,
struct ec_stripe_heap_entry l,
struct ec_stripe_heap_entry r)
{
return ((l.blocks_nonempty > r.blocks_nonempty) -
(l.blocks_nonempty < r.blocks_nonempty));
}
static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
size_t i)
{
@ -1026,39 +1018,71 @@ static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
}
static inline bool ec_stripes_heap_cmp(const void *l, const void *r, void __always_unused *args)
{
struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l;
struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r;
return ((_l->blocks_nonempty > _r->blocks_nonempty) <
(_l->blocks_nonempty < _r->blocks_nonempty));
}
static inline void ec_stripes_heap_swap(void *l, void *r, void *h)
{
struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l;
struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r;
ec_stripes_heap *_h = (ec_stripes_heap *)h;
size_t i = _l - _h->data;
size_t j = _r - _h->data;
swap(*_l, *_r);
ec_stripes_heap_set_backpointer(_h, i);
ec_stripes_heap_set_backpointer(_h, j);
}
static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
{
ec_stripes_heap *h = &c->ec_stripes_heap;
struct stripe *m = genradix_ptr(&c->stripes, idx);
BUG_ON(m->heap_idx >= h->used);
BUG_ON(m->heap_idx >= h->nr);
BUG_ON(h->data[m->heap_idx].idx != idx);
}
void bch2_stripes_heap_del(struct bch_fs *c,
struct stripe *m, size_t idx)
{
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
mutex_lock(&c->ec_stripes_heap_lock);
heap_verify_backpointer(c, idx);
heap_del(&c->ec_stripes_heap, m->heap_idx,
ec_stripes_heap_cmp,
ec_stripes_heap_set_backpointer);
min_heap_del(&c->ec_stripes_heap, m->heap_idx, &callbacks, &c->ec_stripes_heap);
mutex_unlock(&c->ec_stripes_heap_lock);
}
void bch2_stripes_heap_insert(struct bch_fs *c,
struct stripe *m, size_t idx)
{
mutex_lock(&c->ec_stripes_heap_lock);
BUG_ON(heap_full(&c->ec_stripes_heap));
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) {
mutex_lock(&c->ec_stripes_heap_lock);
BUG_ON(min_heap_full(&c->ec_stripes_heap));
genradix_ptr(&c->stripes, idx)->heap_idx = c->ec_stripes_heap.nr;
min_heap_push(&c->ec_stripes_heap, &((struct ec_stripe_heap_entry) {
.idx = idx,
.blocks_nonempty = m->blocks_nonempty,
}),
ec_stripes_heap_cmp,
ec_stripes_heap_set_backpointer);
&callbacks,
&c->ec_stripes_heap);
heap_verify_backpointer(c, idx);
mutex_unlock(&c->ec_stripes_heap_lock);
@ -1067,6 +1091,10 @@ void bch2_stripes_heap_insert(struct bch_fs *c,
void bch2_stripes_heap_update(struct bch_fs *c,
struct stripe *m, size_t idx)
{
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
ec_stripes_heap *h = &c->ec_stripes_heap;
bool do_deletes;
size_t i;
@ -1077,10 +1105,8 @@ void bch2_stripes_heap_update(struct bch_fs *c,
h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
i = m->heap_idx;
heap_sift_up(h, i, ec_stripes_heap_cmp,
ec_stripes_heap_set_backpointer);
heap_sift_down(h, i, ec_stripes_heap_cmp,
ec_stripes_heap_set_backpointer);
min_heap_sift_up(h, i, &callbacks, &c->ec_stripes_heap);
min_heap_sift_down(h, i, &callbacks, &c->ec_stripes_heap);
heap_verify_backpointer(c, idx);
@ -1873,7 +1899,7 @@ static s64 get_existing_stripe(struct bch_fs *c,
return -1;
mutex_lock(&c->ec_stripes_heap_lock);
for (heap_idx = 0; heap_idx < h->used; heap_idx++) {
for (heap_idx = 0; heap_idx < h->nr; heap_idx++) {
/* No blocks worth reusing, stripe will just be deleted: */
if (!h->data[heap_idx].blocks_nonempty)
continue;
@ -2204,7 +2230,7 @@ void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
size_t i;
mutex_lock(&c->ec_stripes_heap_lock);
for (i = 0; i < min_t(size_t, h->used, 50); i++) {
for (i = 0; i < min_t(size_t, h->nr, 50); i++) {
m = genradix_ptr(&c->stripes, h->data[i].idx);
prt_printf(out, "%zu %u/%u+%u", h->data[i].idx,

View File

@ -36,6 +36,6 @@ struct ec_stripe_heap_entry {
unsigned blocks_nonempty;
};
typedef HEAP(struct ec_stripe_heap_entry) ec_stripes_heap;
typedef DEFINE_MIN_HEAP(struct ec_stripe_heap_entry, ec_stripes_heap) ec_stripes_heap;
#endif /* _BCACHEFS_EC_TYPES_H */

View File

@ -8,6 +8,7 @@
#include <linux/errno.h>
#include <linux/freezer.h>
#include <linux/kernel.h>
#include <linux/min_heap.h>
#include <linux/sched/clock.h>
#include <linux/llist.h>
#include <linux/log2.h>
@ -54,17 +55,9 @@ static inline size_t buf_pages(void *p, size_t len)
PAGE_SIZE);
}
#define HEAP(type) \
struct { \
size_t size, used; \
type *data; \
}
#define DECLARE_HEAP(type, name) HEAP(type) name
#define init_heap(heap, _size, gfp) \
({ \
(heap)->used = 0; \
(heap)->nr = 0; \
(heap)->size = (_size); \
(heap)->data = kvmalloc((heap)->size * sizeof((heap)->data[0]),\
(gfp)); \
@ -76,113 +69,6 @@ do { \
(heap)->data = NULL; \
} while (0)
#define heap_set_backpointer(h, i, _fn) \
do { \
void (*fn)(typeof(h), size_t) = _fn; \
if (fn) \
fn(h, i); \
} while (0)
#define heap_swap(h, i, j, set_backpointer) \
do { \
swap((h)->data[i], (h)->data[j]); \
heap_set_backpointer(h, i, set_backpointer); \
heap_set_backpointer(h, j, set_backpointer); \
} while (0)
#define heap_peek(h) \
({ \
EBUG_ON(!(h)->used); \
(h)->data[0]; \
})
#define heap_full(h) ((h)->used == (h)->size)
#define heap_sift_down(h, i, cmp, set_backpointer) \
do { \
size_t _c, _j = i; \
\
for (; _j * 2 + 1 < (h)->used; _j = _c) { \
_c = _j * 2 + 1; \
if (_c + 1 < (h)->used && \
cmp(h, (h)->data[_c], (h)->data[_c + 1]) >= 0) \
_c++; \
\
if (cmp(h, (h)->data[_c], (h)->data[_j]) >= 0) \
break; \
heap_swap(h, _c, _j, set_backpointer); \
} \
} while (0)
#define heap_sift_up(h, i, cmp, set_backpointer) \
do { \
while (i) { \
size_t p = (i - 1) / 2; \
if (cmp(h, (h)->data[i], (h)->data[p]) >= 0) \
break; \
heap_swap(h, i, p, set_backpointer); \
i = p; \
} \
} while (0)
#define __heap_add(h, d, cmp, set_backpointer) \
({ \
size_t _i = (h)->used++; \
(h)->data[_i] = d; \
heap_set_backpointer(h, _i, set_backpointer); \
\
heap_sift_up(h, _i, cmp, set_backpointer); \
_i; \
})
#define heap_add(h, d, cmp, set_backpointer) \
({ \
bool _r = !heap_full(h); \
if (_r) \
__heap_add(h, d, cmp, set_backpointer); \
_r; \
})
#define heap_add_or_replace(h, new, cmp, set_backpointer) \
do { \
if (!heap_add(h, new, cmp, set_backpointer) && \
cmp(h, new, heap_peek(h)) >= 0) { \
(h)->data[0] = new; \
heap_set_backpointer(h, 0, set_backpointer); \
heap_sift_down(h, 0, cmp, set_backpointer); \
} \
} while (0)
#define heap_del(h, i, cmp, set_backpointer) \
do { \
size_t _i = (i); \
\
BUG_ON(_i >= (h)->used); \
(h)->used--; \
if ((_i) < (h)->used) { \
heap_swap(h, _i, (h)->used, set_backpointer); \
heap_sift_up(h, _i, cmp, set_backpointer); \
heap_sift_down(h, _i, cmp, set_backpointer); \
} \
} while (0)
#define heap_pop(h, d, cmp, set_backpointer) \
({ \
bool _r = (h)->used; \
if (_r) { \
(d) = (h)->data[0]; \
heap_del(h, 0, cmp, set_backpointer); \
} \
_r; \
})
#define heap_resort(heap, cmp, set_backpointer) \
do { \
ssize_t _i; \
for (_i = (ssize_t) (heap)->used / 2 - 1; _i >= 0; --_i) \
heap_sift_down(heap, _i, cmp, set_backpointer); \
} while (0)
#define ANYSINT_MAX(t) \
((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)