diff options
| author | Dennis Zhou <dennis@kernel.org> | 2019-02-04 15:20:07 -0500 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2019-02-25 14:13:33 +0100 |
| commit | d3c6ab752c4145cba9af85021f02bc4655534f93 (patch) | |
| tree | 619cc94662837e3fb69c38bb1a1173c95f218e5c /fs/btrfs | |
| parent | e0dc87afcdb890e542f6080296ce591cd348c25d (diff) | |
| download | linux-d3c6ab752c4145cba9af85021f02bc4655534f93.tar.bz2 | |
btrfs: make zstd memory requirements monotonic
It is possible based on the level configurations that a higher level
workspace uses less memory than a lower level workspace. In order to
reuse workspaces, this must be made a monotonic relationship. This
precomputes the required memory for each level and enforces the
monotonicity between level and memory required. This is also done
in upstream zstd in [1].
[1] https://github.com/facebook/zstd/commit/a68b76afefec6876f8e8a538155109a5aeac0143
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/zstd.c | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c index a951d4fe77f7..65018c401c46 100644 --- a/fs/btrfs/zstd.c +++ b/fs/btrfs/zstd.c @@ -20,6 +20,7 @@ #define ZSTD_BTRFS_MAX_WINDOWLOG 17 #define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG) #define ZSTD_BTRFS_DEFAULT_LEVEL 3 +#define ZSTD_BTRFS_MAX_LEVEL 15 static ZSTD_parameters zstd_get_btrfs_parameters(unsigned int level, size_t src_len) @@ -44,8 +45,39 @@ struct workspace { static struct workspace_manager wsm; +static size_t zstd_ws_mem_sizes[ZSTD_BTRFS_MAX_LEVEL]; + +/* + * zstd_calc_ws_mem_sizes - calculate monotonic memory bounds + * + * It is possible based on the level configurations that a higher level + * workspace uses less memory than a lower level workspace. In order to reuse + * workspaces, this must be made a monotonic relationship. This precomputes + * the required memory for each level and enforces the monotonicity between + * level and memory required. + */ +static void zstd_calc_ws_mem_sizes(void) +{ + size_t max_size = 0; + unsigned int level; + + for (level = 1; level <= ZSTD_BTRFS_MAX_LEVEL; level++) { + ZSTD_parameters params = + zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); + size_t level_size = + max_t(size_t, + ZSTD_CStreamWorkspaceBound(params.cParams), + ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT)); + + max_size = max_t(size_t, max_size, level_size); + zstd_ws_mem_sizes[level - 1] = max_size; + } +} + static void zstd_init_workspace_manager(void) { + zstd_calc_ws_mem_sizes(); + btrfs_init_workspace_manager(&wsm, &btrfs_zstd_compress); } @@ -80,17 +112,13 @@ static void zstd_free_workspace(struct list_head *ws) static struct list_head *zstd_alloc_workspace(unsigned int level) { - ZSTD_parameters params = - zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); struct workspace *workspace; workspace = kzalloc(sizeof(*workspace), GFP_KERNEL); if (!workspace) return ERR_PTR(-ENOMEM); - workspace->size = max_t(size_t, - ZSTD_CStreamWorkspaceBound(params.cParams), - ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT)); + workspace->size = zstd_ws_mem_sizes[level - 1]; workspace->mem = kvmalloc(workspace->size, GFP_KERNEL); workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!workspace->mem || !workspace->buf) |