diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2014-01-13 19:13:05 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-01-14 23:23:03 -0500 |
| commit | 55b082e614e219fb5199a6f93e648ed35d3c96d5 (patch) | |
| tree | a2707e62bdd914e9651e78cde6cb55a5f0b88d7f /drivers/md/dm-bufio.h | |
| parent | 55494bf2947dccdf2d98b62374fea7365dfead84 (diff) | |
dm snapshot: use dm-bufio prefetch
This patch modifies dm-snapshot so that it prefetches the buffers when
loading the exceptions.
The number of buffers read ahead is specified in the DM_PREFETCH_CHUNKS
macro. The current value for DM_PREFETCH_CHUNKS (12) was found to
provide the best performance on a single 15k SCSI spindle. In the
future we may modify this default or make it configurable.
Also, introduce the function dm_bufio_set_minimum_buffers to setup
bufio's number of internal buffers before freeing happens. dm-bufio may
hold more buffers if enough memory is available. There is no guarantee
that the specified number of buffers will be available - if you need a
guarantee, use the argument reserved_buffers for
dm_bufio_client_create.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-bufio.h')
| -rw-r--r-- | drivers/md/dm-bufio.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/md/dm-bufio.h b/drivers/md/dm-bufio.h index 3dac37627ba4..c096779a7292 100644 --- a/drivers/md/dm-bufio.h +++ b/drivers/md/dm-bufio.h @@ -115,6 +115,11 @@ void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block); */ void dm_bufio_forget(struct dm_bufio_client *c, sector_t block); +/* + * Set the minimum number of buffers before cleanup happens. + */ +void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n); + unsigned dm_bufio_get_block_size(struct dm_bufio_client *c); sector_t dm_bufio_get_device_size(struct dm_bufio_client *c); sector_t dm_bufio_get_block_number(struct dm_buffer *b); |