linux/fs/btrfs/discard.h
Dennis Zhou a230930084 btrfs: calculate discard delay based on number of extents
An earlier patch keeps track of discardable_extents. These are
undiscarded extents managed by the free space cache. Here, we will use
this to dynamically calculate the discard delay interval.

There are 3 rate to consider. The first is the target convergence rate,
the rate to discard all discardable_extents over the
BTRFS_DISCARD_TARGET_MSEC time frame. This is clamped by the lower
limit, the iops limit or BTRFS_DISCARD_MIN_DELAY (1ms), and the upper
limit, BTRFS_DISCARD_MAX_DELAY (1s). We reevaluate this delay every
transaction commit.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00

32 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef BTRFS_DISCARD_H
#define BTRFS_DISCARD_H
struct btrfs_fs_info;
struct btrfs_discard_ctl;
struct btrfs_block_group;
/* Work operations */
void btrfs_discard_cancel_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group);
void btrfs_discard_queue_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group);
void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl,
bool override);
bool btrfs_run_discard_work(struct btrfs_discard_ctl *discard_ctl);
/* Update operations */
void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl);
void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
struct btrfs_free_space_ctl *ctl);
/* Setup/cleanup operations */
void btrfs_discard_punt_unused_bgs_list(struct btrfs_fs_info *fs_info);
void btrfs_discard_resume(struct btrfs_fs_info *fs_info);
void btrfs_discard_stop(struct btrfs_fs_info *fs_info);
void btrfs_discard_init(struct btrfs_fs_info *fs_info);
void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info);
#endif