Some SSDs perform best when reusing block numbers often, while
others perform much better when clustering strictly allocates
big chunks of unused space.
The default mount -o ssd will find rough groupings of blocks
where there are a bunch of free blocks that might have some
allocated blocks mixed in.
mount -o ssd_spread will make sure there are no allocated blocks
mixed in. It should perform better on lower end SSDs.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
#define BTRFS_MOUNT_COMPRESS (1 << 5)
#define BTRFS_MOUNT_NOTREELOG (1 << 6)
#define BTRFS_MOUNT_FLUSHONCOMMIT (1 << 7)
#define BTRFS_MOUNT_COMPRESS (1 << 5)
#define BTRFS_MOUNT_NOTREELOG (1 << 6)
#define BTRFS_MOUNT_FLUSHONCOMMIT (1 << 7)
+#define BTRFS_MOUNT_SSD_SPREAD (1 << 8)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
last_ptr_loop = 0;
/* allocate a cluster in this block group */
last_ptr_loop = 0;
/* allocate a cluster in this block group */
- ret = btrfs_find_space_cluster(trans,
+ ret = btrfs_find_space_cluster(trans, root,
block_group, last_ptr,
offset, num_bytes,
empty_cluster + empty_size);
block_group, last_ptr,
offset, num_bytes,
empty_cluster + empty_size);
* it returns -enospc
*/
int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
* it returns -enospc
*/
int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 empty_size)
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 empty_size)
int ret;
/* for metadata, allow allocates with more holes */
int ret;
/* for metadata, allow allocates with more holes */
- if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
+ if (btrfs_test_opt(root, SSD_SPREAD)) {
+ min_bytes = bytes + empty_size;
+ } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
/*
* we want to do larger allocations when we are
* flushing out the delayed refs, it helps prevent
/*
* we want to do larger allocations when we are
* flushing out the delayed refs, it helps prevent
u64 bytes);
u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
u64 bytes);
u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group);
int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 empty_size);
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 empty_size);
enum {
Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
enum {
Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
- Opt_ssd, Opt_nossd, Opt_thread_pool, Opt_noacl, Opt_compress,
- Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err,
+ Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
+ Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err,
};
static match_table_t tokens = {
};
static match_table_t tokens = {
{Opt_thread_pool, "thread_pool=%d"},
{Opt_compress, "compress"},
{Opt_ssd, "ssd"},
{Opt_thread_pool, "thread_pool=%d"},
{Opt_compress, "compress"},
{Opt_ssd, "ssd"},
+ {Opt_ssd_spread, "ssd_spread"},
{Opt_nossd, "nossd"},
{Opt_noacl, "noacl"},
{Opt_notreelog, "notreelog"},
{Opt_nossd, "nossd"},
{Opt_noacl, "noacl"},
{Opt_notreelog, "notreelog"},
printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
btrfs_set_opt(info->mount_opt, SSD);
break;
printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
btrfs_set_opt(info->mount_opt, SSD);
break;
+ case Opt_ssd_spread:
+ printk(KERN_INFO "btrfs: use spread ssd "
+ "allocation scheme\n");
+ btrfs_set_opt(info->mount_opt, SSD);
+ btrfs_set_opt(info->mount_opt, SSD_SPREAD);
+ break;
- printk(KERN_INFO "btrfs: not using ssd allocation scheme\n");
+ printk(KERN_INFO "btrfs: not using ssd allocation "
+ "scheme\n");
btrfs_clear_opt(info->mount_opt, SSD);
btrfs_clear_opt(info->mount_opt, SSD);
+ btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
break;
case Opt_nobarrier:
printk(KERN_INFO "btrfs: turning off barriers\n");
break;
case Opt_nobarrier:
printk(KERN_INFO "btrfs: turning off barriers\n");
seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
if (btrfs_test_opt(root, COMPRESS))
seq_puts(seq, ",compress");
seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
if (btrfs_test_opt(root, COMPRESS))
seq_puts(seq, ",compress");
- if (btrfs_test_opt(root, SSD))
+ if (btrfs_test_opt(root, SSD_SPREAD))
+ seq_puts(seq, ",ssd_spread");
+ else if (btrfs_test_opt(root, SSD))
seq_puts(seq, ",ssd");
if (btrfs_test_opt(root, NOTREELOG))
seq_puts(seq, ",notreelog");
seq_puts(seq, ",ssd");
if (btrfs_test_opt(root, NOTREELOG))
seq_puts(seq, ",notreelog");