*/
#include "bcachefs.h"
+#include "alloc_foreground.h"
#include "btree_iter.h"
+#include "btree_update.h"
#include "buckets.h"
#include "clock.h"
+#include "disk_groups.h"
#include "extents.h"
#include "eytzinger.h"
#include "io.h"
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/math64.h>
+#include <linux/sched/task.h>
#include <linux/sort.h>
#include <linux/wait.h>
-/* Moving GC - IO loop */
-
-static int bucket_idx_cmp(const void *_l, const void *_r, size_t size)
-{
- const struct bucket_heap_entry *l = _l;
- const struct bucket_heap_entry *r = _r;
+/*
+ * We can't use the entire copygc reserve in one iteration of copygc: we may
+ * need the buckets we're freeing up to go back into the copygc reserve to make
+ * forward progress, but if the copygc reserve is full they'll be available for
+ * any allocation - and it's possible that in a given iteration, we free up most
+ * of the buckets we're going to free before we allocate most of the buckets
+ * we're going to allocate.
+ *
+ * If we only use half of the reserve per iteration, then in steady state we'll
+ * always have room in the reserve for the buckets we're going to need in the
+ * next iteration:
+ */
+#define COPYGC_BUCKETS_PER_ITER(ca) \
+ ((ca)->free[RESERVE_MOVINGGC].size / 2)
- if (l->bucket < r->bucket)
- return -1;
- if (l->bucket > r->bucket)
- return 1;
- return 0;
-}
+/*
+ * Max sectors to move per iteration: Have to take into account internal
+ * fragmentation from the multiple write points for each generation:
+ */
+#define COPYGC_SECTORS_PER_ITER(ca) \
+ ((ca)->mi.bucket_size * COPYGC_BUCKETS_PER_ITER(ca))
-static const struct bch_extent_ptr *moving_pred(struct bch_dev *ca,
- struct bkey_s_c k)
+static inline int sectors_used_cmp(copygc_heap *heap,
+ struct copygc_heap_entry l,
+ struct copygc_heap_entry r)
{
- bucket_heap *h = &ca->copygc_heap;
- const struct bch_extent_ptr *ptr;
-
- if (bkey_extent_is_data(k.k) &&
- (ptr = bch2_extent_has_device(bkey_s_c_to_extent(k),
- ca->dev_idx))) {
- struct bucket_heap_entry search = {
- .bucket = PTR_BUCKET_NR(ca, ptr)
- };
-
- size_t i = eytzinger0_find(h->data, h->used,
- sizeof(h->data[0]),
- bucket_idx_cmp, &search);
-
- if (i < h->used)
- return ptr;
- }
-
- return NULL;
+ return (l.sectors > r.sectors) - (l.sectors < r.sectors);
}
-static int issue_moving_gc_move(struct bch_dev *ca,
- struct moving_context *ctxt,
- struct bkey_s_c k)
+static int bucket_offset_cmp(const void *_l, const void *_r, size_t size)
{
- struct bch_fs *c = ca->fs;
- const struct bch_extent_ptr *ptr;
- int ret;
-
- ptr = moving_pred(ca, k);
- if (!ptr) /* We raced - bucket's been reused */
- return 0;
+ const struct copygc_heap_entry *l = _l;
+ const struct copygc_heap_entry *r = _r;
- ret = bch2_data_move(c, ctxt, &ca->self, k, ptr);
- if (!ret)
- trace_gc_copy(k.k);
- else
- trace_moving_gc_alloc_fail(c, k.k->size);
- return ret;
+ return (l->offset > r->offset) - (l->offset < r->offset);
}
-static void read_moving(struct bch_dev *ca, size_t buckets_to_move,
- u64 sectors_to_move)
+static bool __copygc_pred(struct bch_dev *ca,
+ struct bkey_s_c k)
{
- struct bch_fs *c = ca->fs;
- bucket_heap *h = &ca->copygc_heap;
- struct moving_context ctxt;
- struct btree_iter iter;
- struct bkey_s_c k;
- u64 sectors_not_moved = 0;
- size_t buckets_not_moved = 0;
- struct bucket_heap_entry *i;
-
- bch2_ratelimit_reset(&ca->moving_gc_pd.rate);
- bch2_move_ctxt_init(&ctxt, &ca->moving_gc_pd.rate,
- SECTORS_IN_FLIGHT_PER_DEVICE);
- bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN,
- BTREE_ITER_PREFETCH);
-
- while (1) {
- if (kthread_should_stop())
- goto out;
- if (bch2_move_ctxt_wait(&ctxt))
- goto out;
- k = bch2_btree_iter_peek(&iter);
- if (!k.k)
- break;
- if (btree_iter_err(k))
- goto out;
+ copygc_heap *h = &ca->copygc_heap;
- if (!moving_pred(ca, k))
- goto next;
+ switch (k.k->type) {
+ case KEY_TYPE_extent: {
+ struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
+ const struct bch_extent_ptr *ptr =
+ bch2_extent_has_device(e, ca->dev_idx);
- if (issue_moving_gc_move(ca, &ctxt, k)) {
- bch2_btree_iter_unlock(&iter);
+ if (ptr) {
+ struct copygc_heap_entry search = { .offset = ptr->offset };
- /* memory allocation failure, wait for some IO to finish */
- bch2_move_ctxt_wait_for_io(&ctxt);
- continue;
- }
-next:
- bch2_btree_iter_advance_pos(&iter);
- //bch2_btree_iter_cond_resched(&iter);
+ ssize_t i = eytzinger0_find_le(h->data, h->used,
+ sizeof(h->data[0]),
+ bucket_offset_cmp, &search);
- /* unlock before calling moving_context_wait() */
- bch2_btree_iter_unlock(&iter);
- cond_resched();
+ return (i >= 0 &&
+ ptr->offset < h->data[i].offset + ca->mi.bucket_size &&
+ ptr->gen == h->data[i].gen);
+ }
+ break;
+ }
}
- bch2_btree_iter_unlock(&iter);
- bch2_move_ctxt_exit(&ctxt);
- trace_moving_gc_end(ca, ctxt.sectors_moved, ctxt.keys_moved,
- buckets_to_move);
+ return false;
+}
- /* don't check this if we bailed out early: */
- for (i = h->data; i < h->data + h->used; i++) {
- struct bucket_mark m = READ_ONCE(ca->buckets[i->bucket].mark);
+static enum data_cmd copygc_pred(struct bch_fs *c, void *arg,
+ struct bkey_s_c k,
+ struct bch_io_opts *io_opts,
+ struct data_opts *data_opts)
+{
+ struct bch_dev *ca = arg;
- if (i->mark.gen == m.gen && bucket_sectors_used(m)) {
- sectors_not_moved += bucket_sectors_used(m);
- buckets_not_moved++;
- }
- }
+ if (!__copygc_pred(ca, k))
+ return DATA_SKIP;
- if (sectors_not_moved)
- bch_warn(c, "copygc finished but %llu/%llu sectors, %zu/%zu buckets not moved",
- sectors_not_moved, sectors_to_move,
- buckets_not_moved, buckets_to_move);
- return;
-out:
- bch2_btree_iter_unlock(&iter);
- bch2_move_ctxt_exit(&ctxt);
- trace_moving_gc_end(ca, ctxt.sectors_moved, ctxt.keys_moved,
- buckets_to_move);
+ data_opts->target = dev_to_target(ca->dev_idx);
+ data_opts->btree_insert_flags = BTREE_INSERT_USE_RESERVE;
+ data_opts->rewrite_dev = ca->dev_idx;
+ return DATA_REWRITE;
}
static bool have_copygc_reserve(struct bch_dev *ca)
bool ret;
spin_lock(&ca->freelist_lock);
- ret = fifo_used(&ca->free[RESERVE_MOVINGGC]) >=
- COPYGC_BUCKETS_PER_ITER(ca);
+ ret = fifo_full(&ca->free[RESERVE_MOVINGGC]) ||
+ ca->allocator_blocked;
spin_unlock(&ca->freelist_lock);
return ret;
}
-static inline int sectors_used_cmp(bucket_heap *heap,
- struct bucket_heap_entry l,
- struct bucket_heap_entry r)
+static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
{
- return bucket_sectors_used(l.mark) - bucket_sectors_used(r.mark);
-}
-
-static void bch2_moving_gc(struct bch_dev *ca)
-{
- struct bch_fs *c = ca->fs;
- struct bucket *g;
- u64 sectors_to_move = 0;
- size_t buckets_to_move, buckets_unused = 0;
- struct bucket_heap_entry e, *i;
- int reserve_sectors;
-
- if (!have_copygc_reserve(ca)) {
- struct closure cl;
-
- closure_init_stack(&cl);
- while (1) {
- closure_wait(&c->freelist_wait, &cl);
- if (have_copygc_reserve(ca))
- break;
- closure_sync(&cl);
- }
- closure_wake_up(&c->freelist_wait);
- }
-
- reserve_sectors = COPYGC_SECTORS_PER_ITER(ca);
+ copygc_heap *h = &ca->copygc_heap;
+ struct copygc_heap_entry e, *i;
+ struct bucket_array *buckets;
+ struct bch_move_stats move_stats;
+ u64 sectors_to_move = 0, sectors_not_moved = 0;
+ u64 buckets_to_move, buckets_not_moved = 0;
+ size_t b;
+ int ret;
- trace_moving_gc_start(ca);
+ memset(&move_stats, 0, sizeof(move_stats));
+ closure_wait_event(&c->freelist_wait, have_copygc_reserve(ca));
/*
* Find buckets with lowest sector counts, skipping completely
* and repeatedly replacing the maximum element until all
* buckets have been visited.
*/
+ h->used = 0;
/*
* We need bucket marks to be up to date - gc can't be recalculating
* them:
*/
down_read(&c->gc_lock);
- ca->copygc_heap.used = 0;
- for_each_bucket(g, ca) {
- struct bucket_mark m = READ_ONCE(g->mark);
- struct bucket_heap_entry e = { g - ca->buckets, m };
+ down_read(&ca->bucket_lock);
+ buckets = bucket_array(ca);
- if (bucket_unused(m)) {
- buckets_unused++;
- continue;
- }
+ for (b = buckets->first_bucket; b < buckets->nbuckets; b++) {
+ struct bucket_mark m = READ_ONCE(buckets->b[b].mark);
+ struct copygc_heap_entry e;
if (m.owned_by_allocator ||
- m.data_type != BUCKET_DATA)
- continue;
-
- if (bucket_sectors_used(m) >= ca->mi.bucket_size)
+ m.data_type != BCH_DATA_USER ||
+ !bucket_sectors_used(m) ||
+ bucket_sectors_used(m) >= ca->mi.bucket_size)
continue;
- heap_add_or_replace(&ca->copygc_heap, e, -sectors_used_cmp);
+ e = (struct copygc_heap_entry) {
+ .gen = m.gen,
+ .sectors = bucket_sectors_used(m),
+ .offset = bucket_to_sector(ca, b),
+ };
+ heap_add_or_replace(h, e, -sectors_used_cmp, NULL);
}
+ up_read(&ca->bucket_lock);
up_read(&c->gc_lock);
- for (i = ca->copygc_heap.data;
- i < ca->copygc_heap.data + ca->copygc_heap.used;
- i++)
- sectors_to_move += bucket_sectors_used(i->mark);
+ for (i = h->data; i < h->data + h->used; i++)
+ sectors_to_move += i->sectors;
while (sectors_to_move > COPYGC_SECTORS_PER_ITER(ca)) {
- BUG_ON(!heap_pop(&ca->copygc_heap, e, -sectors_used_cmp));
- sectors_to_move -= bucket_sectors_used(e.mark);
+ BUG_ON(!heap_pop(h, e, -sectors_used_cmp, NULL));
+ sectors_to_move -= e.sectors;
}
- buckets_to_move = ca->copygc_heap.used;
+ buckets_to_move = h->used;
+
+ if (!buckets_to_move)
+ return;
+
+ eytzinger0_sort(h->data, h->used,
+ sizeof(h->data[0]),
+ bucket_offset_cmp, NULL);
+
+ ret = bch2_move_data(c, &ca->copygc_pd.rate,
+ writepoint_ptr(&ca->copygc_write_point),
+ POS_MIN, POS_MAX,
+ copygc_pred, ca,
+ &move_stats);
- eytzinger0_sort(ca->copygc_heap.data,
- ca->copygc_heap.used,
- sizeof(ca->copygc_heap.data[0]),
- bucket_idx_cmp, NULL);
+ down_read(&ca->bucket_lock);
+ buckets = bucket_array(ca);
+ for (i = h->data; i < h->data + h->used; i++) {
+ size_t b = sector_to_bucket(ca, i->offset);
+ struct bucket_mark m = READ_ONCE(buckets->b[b].mark);
+
+ if (i->gen == m.gen && bucket_sectors_used(m)) {
+ sectors_not_moved += bucket_sectors_used(m);
+ buckets_not_moved++;
+ }
+ }
+ up_read(&ca->bucket_lock);
+
+ if (sectors_not_moved && !ret)
+ bch_warn(c, "copygc finished but %llu/%llu sectors, %llu/%llu buckets not moved",
+ sectors_not_moved, sectors_to_move,
+ buckets_not_moved, buckets_to_move);
- read_moving(ca, buckets_to_move, sectors_to_move);
+ trace_copygc(ca,
+ atomic64_read(&move_stats.sectors_moved), sectors_not_moved,
+ buckets_to_move, buckets_not_moved);
}
-static int bch2_moving_gc_thread(void *arg)
+static int bch2_copygc_thread(void *arg)
{
struct bch_dev *ca = arg;
struct bch_fs *c = ca->fs;
struct io_clock *clock = &c->io_clock[WRITE];
+ struct bch_dev_usage usage;
unsigned long last;
- u64 available, want, next;
+ u64 available, fragmented, reserve, next;
set_freezable();
break;
last = atomic_long_read(&clock->now);
+
+ reserve = ca->copygc_threshold;
+
+ usage = bch2_dev_usage_read(c, ca);
+
+ available = __dev_buckets_available(ca, usage) *
+ ca->mi.bucket_size;
+ if (available > reserve) {
+ next = last + available - reserve;
+ bch2_kthread_io_clock_wait(clock, next,
+ MAX_SCHEDULE_TIMEOUT);
+ continue;
+ }
+
/*
- * don't start copygc until less than half the gc reserve is
- * available:
+ * don't start copygc until there's more than half the copygc
+ * reserve of fragmented space:
*/
- available = dev_buckets_available(ca);
- want = div64_u64((ca->mi.nbuckets - ca->mi.first_bucket) *
- c->opts.gc_reserve_percent, 200);
- if (available > want) {
- next = last + (available - want) *
- ca->mi.bucket_size;
- bch2_kthread_io_clock_wait(clock, next);
+ fragmented = usage.sectors_fragmented;
+ if (fragmented < reserve) {
+ next = last + reserve - fragmented;
+ bch2_kthread_io_clock_wait(clock, next,
+ MAX_SCHEDULE_TIMEOUT);
continue;
}
- bch2_moving_gc(ca);
+ bch2_copygc(c, ca);
}
return 0;
}
-void bch2_moving_gc_stop(struct bch_dev *ca)
+void bch2_copygc_stop(struct bch_dev *ca)
{
- ca->moving_gc_pd.rate.rate = UINT_MAX;
- bch2_ratelimit_reset(&ca->moving_gc_pd.rate);
+ ca->copygc_pd.rate.rate = UINT_MAX;
+ bch2_ratelimit_reset(&ca->copygc_pd.rate);
- if (ca->moving_gc_read)
- kthread_stop(ca->moving_gc_read);
- ca->moving_gc_read = NULL;
+ if (ca->copygc_thread) {
+ kthread_stop(ca->copygc_thread);
+ put_task_struct(ca->copygc_thread);
+ }
+ ca->copygc_thread = NULL;
}
-int bch2_moving_gc_start(struct bch_dev *ca)
+int bch2_copygc_start(struct bch_fs *c, struct bch_dev *ca)
{
struct task_struct *t;
- BUG_ON(ca->moving_gc_read);
+ BUG_ON(ca->copygc_thread);
- if (ca->fs->opts.nochanges)
+ if (c->opts.nochanges)
return 0;
- if (bch2_fs_init_fault("moving_gc_start"))
+ if (bch2_fs_init_fault("copygc_start"))
return -ENOMEM;
- t = kthread_create(bch2_moving_gc_thread, ca, "bch_copygc_read");
+ t = kthread_create(bch2_copygc_thread, ca,
+ "bch_copygc[%s]", ca->name);
if (IS_ERR(t))
return PTR_ERR(t);
- ca->moving_gc_read = t;
- wake_up_process(ca->moving_gc_read);
+ get_task_struct(t);
+
+ ca->copygc_thread = t;
+ wake_up_process(ca->copygc_thread);
return 0;
}
-void bch2_dev_moving_gc_init(struct bch_dev *ca)
+void bch2_dev_copygc_init(struct bch_dev *ca)
{
- bch2_pd_controller_init(&ca->moving_gc_pd);
- ca->moving_gc_pd.d_term = 0;
+ bch2_pd_controller_init(&ca->copygc_pd);
+ ca->copygc_pd.d_term = 0;
}
projects / bcachefs-tools-debian / blobdiff