提交 ab966241 编写于 作者: C Coly Li 提交者: Greg Kroah-Hartman

bcache: Revert "bcache: fix high CPU occupancy during journal"

commit 249a5f6da57c28a903c75d81505d58ec8c10030d upstream.

This reverts commit c4dc2497.

This patch enlarges a race between normal btree flush code path and
flush_btree_write(), which causes deadlock when journal space is
exhausted. Reverts this patch makes the race window from 128 btree
nodes to only 1 btree nodes.

Fixes: c4dc2497 ("bcache: fix high CPU occupancy during journal")
Signed-off-by: NColy Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Tang Junhui <tang.junhui.linux@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
上级 58169c18
......@@ -708,8 +708,6 @@ struct cache_set {
#define BUCKET_HASH_BITS 12
struct hlist_head bucket_hash[1 << BUCKET_HASH_BITS];
DECLARE_HEAP(struct btree *, flush_btree);
};
struct bbio {
......
......@@ -390,12 +390,6 @@ int bch_journal_replay(struct cache_set *s, struct list_head *list)
}
/* Journalling */
#define journal_max_cmp(l, r) \
(fifo_idx(&c->journal.pin, btree_current_write(l)->journal) < \
fifo_idx(&(c)->journal.pin, btree_current_write(r)->journal))
#define journal_min_cmp(l, r) \
(fifo_idx(&c->journal.pin, btree_current_write(l)->journal) > \
fifo_idx(&(c)->journal.pin, btree_current_write(r)->journal))
static void btree_flush_write(struct cache_set *c)
{
......@@ -403,35 +397,25 @@ static void btree_flush_write(struct cache_set *c)
* Try to find the btree node with that references the oldest journal
* entry, best is our current candidate and is locked if non NULL:
*/
struct btree *b;
int i;
struct btree *b, *best;
unsigned int i;
atomic_long_inc(&c->flush_write);
retry:
spin_lock(&c->journal.lock);
if (heap_empty(&c->flush_btree)) {
for_each_cached_btree(b, c, i)
if (btree_current_write(b)->journal) {
if (!heap_full(&c->flush_btree))
heap_add(&c->flush_btree, b,
journal_max_cmp);
else if (journal_max_cmp(b,
heap_peek(&c->flush_btree))) {
c->flush_btree.data[0] = b;
heap_sift(&c->flush_btree, 0,
journal_max_cmp);
}
best = NULL;
for_each_cached_btree(b, c, i)
if (btree_current_write(b)->journal) {
if (!best)
best = b;
else if (journal_pin_cmp(c,
btree_current_write(best)->journal,
btree_current_write(b)->journal)) {
best = b;
}
}
for (i = c->flush_btree.used / 2 - 1; i >= 0; --i)
heap_sift(&c->flush_btree, i, journal_min_cmp);
}
b = NULL;
heap_pop(&c->flush_btree, b, journal_min_cmp);
spin_unlock(&c->journal.lock);
b = best;
if (b) {
mutex_lock(&b->write_lock);
if (!btree_current_write(b)->journal) {
......@@ -873,8 +857,7 @@ int bch_journal_alloc(struct cache_set *c)
j->w[0].c = c;
j->w[1].c = c;
if (!(init_heap(&c->flush_btree, 128, GFP_KERNEL)) ||
!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
!(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) ||
!(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)))
return -ENOMEM;
......
......@@ -113,8 +113,6 @@ do { \
#define heap_full(h) ((h)->used == (h)->size)
#define heap_empty(h) ((h)->used == 0)
#define DECLARE_FIFO(type, name) \
struct { \
size_t front, back, size, mask; \
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册