mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Coly Li](/assets/img/avatar_default.png)
Commitb144e45fc5
("bcache: make bch_sectors_dirty_init() to be multithreaded") makes bch_sectors_dirty_init() to be much faster when counting dirty sectors by iterating all dirty keys in the btree. But it isn't in ideal shape yet, still can be improved. This patch does the following changes to improve current parallel dirty keys iteration on the btree, - Add read lock to root node when multiple threads iterating the btree, to prevent the root node gets split by I/Os from other registered bcache devices. - Remove local variable "char name[32]" and generate kernel thread name string directly when calling kthread_run(). - Allocate "struct bch_dirty_init_state state" directly on stack and avoid the unnecessary dynamic memory allocation for it. - Decrease BCH_DIRTY_INIT_THRD_MAX from 64 to 12 which is enough indeed. - Increase &state->started to count created kernel thread after it succeeds to create. - When wait for all dirty key counting threads to finish, use wait_event() to replace wait_event_interruptible(). With the above changes, the code is more clear, and some potential error conditions are avoided. Fixes:b144e45fc5
("bcache: make bch_sectors_dirty_init() to be multithreaded") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220524102336.10684-3-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
155 lines
3.8 KiB
C
155 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _BCACHE_WRITEBACK_H
|
|
#define _BCACHE_WRITEBACK_H
|
|
|
|
#define CUTOFF_WRITEBACK 40
|
|
#define CUTOFF_WRITEBACK_SYNC 70
|
|
|
|
#define CUTOFF_WRITEBACK_MAX 70
|
|
#define CUTOFF_WRITEBACK_SYNC_MAX 90
|
|
|
|
#define MAX_WRITEBACKS_IN_PASS 5
|
|
#define MAX_WRITESIZE_IN_PASS 5000 /* *512b */
|
|
|
|
#define WRITEBACK_RATE_UPDATE_SECS_MAX 60
|
|
#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT 5
|
|
|
|
#define BCH_AUTO_GC_DIRTY_THRESHOLD 50
|
|
|
|
#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW 50
|
|
#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID 57
|
|
#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH 64
|
|
|
|
#define BCH_DIRTY_INIT_THRD_MAX 12
|
|
/*
|
|
* 14 (16384ths) is chosen here as something that each backing device
|
|
* should be a reasonable fraction of the share, and not to blow up
|
|
* until individual backing devices are a petabyte.
|
|
*/
|
|
#define WRITEBACK_SHARE_SHIFT 14
|
|
|
|
struct bch_dirty_init_state;
|
|
struct dirty_init_thrd_info {
|
|
struct bch_dirty_init_state *state;
|
|
struct task_struct *thread;
|
|
};
|
|
|
|
struct bch_dirty_init_state {
|
|
struct cache_set *c;
|
|
struct bcache_device *d;
|
|
int total_threads;
|
|
int key_idx;
|
|
spinlock_t idx_lock;
|
|
atomic_t started;
|
|
atomic_t enough;
|
|
wait_queue_head_t wait;
|
|
struct dirty_init_thrd_info infos[BCH_DIRTY_INIT_THRD_MAX];
|
|
};
|
|
|
|
static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
|
|
{
|
|
uint64_t i, ret = 0;
|
|
|
|
for (i = 0; i < d->nr_stripes; i++)
|
|
ret += atomic_read(d->stripe_sectors_dirty + i);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline int offset_to_stripe(struct bcache_device *d,
|
|
uint64_t offset)
|
|
{
|
|
do_div(offset, d->stripe_size);
|
|
|
|
/* d->nr_stripes is in range [1, INT_MAX] */
|
|
if (unlikely(offset >= d->nr_stripes)) {
|
|
pr_err("Invalid stripe %llu (>= nr_stripes %d).\n",
|
|
offset, d->nr_stripes);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Here offset is definitly smaller than INT_MAX,
|
|
* return it as int will never overflow.
|
|
*/
|
|
return offset;
|
|
}
|
|
|
|
static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
|
|
uint64_t offset,
|
|
unsigned int nr_sectors)
|
|
{
|
|
int stripe = offset_to_stripe(&dc->disk, offset);
|
|
|
|
if (stripe < 0)
|
|
return false;
|
|
|
|
while (1) {
|
|
if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
|
|
return true;
|
|
|
|
if (nr_sectors <= dc->disk.stripe_size)
|
|
return false;
|
|
|
|
nr_sectors -= dc->disk.stripe_size;
|
|
stripe++;
|
|
}
|
|
}
|
|
|
|
extern unsigned int bch_cutoff_writeback;
|
|
extern unsigned int bch_cutoff_writeback_sync;
|
|
|
|
static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
|
|
unsigned int cache_mode, bool would_skip)
|
|
{
|
|
unsigned int in_use = dc->disk.c->gc_stats.in_use;
|
|
|
|
if (cache_mode != CACHE_MODE_WRITEBACK ||
|
|
test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
|
|
in_use > bch_cutoff_writeback_sync)
|
|
return false;
|
|
|
|
if (bio_op(bio) == REQ_OP_DISCARD)
|
|
return false;
|
|
|
|
if (dc->partial_stripes_expensive &&
|
|
bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
|
|
bio_sectors(bio)))
|
|
return true;
|
|
|
|
if (would_skip)
|
|
return false;
|
|
|
|
return (op_is_sync(bio->bi_opf) ||
|
|
bio->bi_opf & (REQ_META|REQ_PRIO) ||
|
|
in_use <= bch_cutoff_writeback);
|
|
}
|
|
|
|
static inline void bch_writeback_queue(struct cached_dev *dc)
|
|
{
|
|
if (!IS_ERR_OR_NULL(dc->writeback_thread))
|
|
wake_up_process(dc->writeback_thread);
|
|
}
|
|
|
|
static inline void bch_writeback_add(struct cached_dev *dc)
|
|
{
|
|
if (!atomic_read(&dc->has_dirty) &&
|
|
!atomic_xchg(&dc->has_dirty, 1)) {
|
|
if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
|
|
SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
|
|
/* XXX: should do this synchronously */
|
|
bch_write_bdev_super(dc, NULL);
|
|
}
|
|
|
|
bch_writeback_queue(dc);
|
|
}
|
|
}
|
|
|
|
void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
|
|
uint64_t offset, int nr_sectors);
|
|
|
|
void bch_sectors_dirty_init(struct bcache_device *d);
|
|
void bch_cached_dev_writeback_init(struct cached_dev *dc);
|
|
int bch_cached_dev_writeback_start(struct cached_dev *dc);
|
|
|
|
#endif
|