Github/littlefs
1
Fork 0
Code Actions Activity

Added inline_max, to optionally limit the size of inlined files

Browse Source 
Inlined files live in metadata and decrease storage requirements, but
may be limited to improve metadata-related performance. This is
especially important given the current plague of metadata performance.

Though decreasing inline_max may make metadata more dense and increase
block usage, so it's important to benchmark if optimizing for speed.

The underlying limits of inlined files haven't changed:
1. Inlined files need to fit in RAM, so <= cache_size
2. Inlined files need to fit in a single attr, so <= attr_max
3. Inlined files need to fit in 1/8 of a block to avoid metadata
   overflow issues, this is after limiting by metadata_max,
   so <= min(metadata_max, block_size)/8

By default, the largest possible inline_max is used. This preserves
backwards compatibility and is probably a good default for most use
cases.

This does have the awkward effect of requiring inline_max=-1 to
indicate disabled inlined files, but I don't think there's a good
way around this.
This commit is contained in:
Christopher Haster
2023-12-20 22:56:26 -06:00
parent 09972a1710
commit 8b8fd14187
7 changed files with 79 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/test_files.toml
+18 -3
View File
@@ -1,5 +1,6 @@
[cases.test_files_simple]
defines.INLINE_MAX = [0, -1, 8]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
@@ -25,6 +26,7 @@ code = '''
[cases.test_files_large]
defines.SIZE = [32, 8192, 262144, 0, 7, 8193]
defines.CHUNKSIZE = [31, 16, 33, 1, 1023]
defines.INLINE_MAX = [0, -1, 8]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
@@ -67,6 +69,7 @@ code = '''
defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
defines.CHUNKSIZE = [31, 16, 1]
defines.INLINE_MAX = [0, -1, 8]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
@@ -152,6 +155,7 @@ code = '''
defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
defines.CHUNKSIZE = [31, 16, 1]
defines.INLINE_MAX = [0, -1, 8]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
@@ -232,6 +236,7 @@ code = '''
defines.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
defines.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
defines.CHUNKSIZE = [31, 16, 1]
defines.INLINE_MAX = [0, -1, 8]
code = '''
lfs_t lfs;
lfs_format(&lfs, cfg) => 0;
@@ -303,6 +308,7 @@ code = '''
[cases.test_files_reentrant_write]
defines.SIZE = [32, 0, 7, 2049]
defines.CHUNKSIZE = [31, 16, 65]
defines.INLINE_MAX = [0, -1, 8]
reentrant = true
code = '''
lfs_t lfs;
@@ -354,11 +360,20 @@ code = '''
[cases.test_files_reentrant_write_sync]
defines = [
# append (O(n))
{MODE='LFS_O_APPEND', SIZE=[32, 0, 7, 2049], CHUNKSIZE=[31, 16, 65]},
{MODE='LFS_O_APPEND',
SIZE=[32, 0, 7, 2049],
CHUNKSIZE=[31, 16, 65],
INLINE_MAX=[0, -1, 8]},
# truncate (O(n^2))
{MODE='LFS_O_TRUNC', SIZE=[32, 0, 7, 200], CHUNKSIZE=[31, 16, 65]},
{MODE='LFS_O_TRUNC',
SIZE=[32, 0, 7, 200],
CHUNKSIZE=[31, 16, 65],
INLINE_MAX=[0, -1, 8]},
# rewrite (O(n^2))
{MODE=0, SIZE=[32, 0, 7, 200], CHUNKSIZE=[31, 16, 65]},
{MODE=0,
SIZE=[32, 0, 7, 200],
CHUNKSIZE=[31, 16, 65],
INLINE_MAX=[0, -1, 8]},
]
reentrant = true
code = '''