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| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2023-08-10 17:48:59 +0200 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2023-08-11 06:11:17 +0200 |
| commit | ffa09b3bd02427ab631f0c1b64714ce6fc885f61 (patch) | |
| tree | 7b872de63b71a6e3c99c07a7dbd832955f3f35c2 /fs/erofs/Kconfig | |
| parent | Linux 6.5-rc5 (diff) | |
| download | linux-ffa09b3bd02427ab631f0c1b64714ce6fc885f61.tar.xz linux-ffa09b3bd02427ab631f0c1b64714ce6fc885f61.zip | |
erofs: DEFLATE compression support
Add DEFLATE compression as the 3rd supported algorithm.
DEFLATE is a popular generic-purpose compression algorithm for quite
long time (many advanced formats like gzip, zlib, zip, png are all
based on that) as Apple documentation written "If you require
interoperability with non-Apple devices, use COMPRESSION_ZLIB. [1]".
Due to its popularity, there are several hardware on-market DEFLATE
accelerators, such as (s390) DFLTCC, (Intel) IAA/QAT, (HiSilicon) ZIP
accelerator, etc. In addition, there are also several high-performence
IP cores and even open-source FPGA approches available for DEFLATE.
Therefore, it's useful to support DEFLATE compression in order to find
a way to utilize these accelerators for asynchronous I/Os and get
benefits from these later.
Besides, it's a good choice to trade off between compression ratios
and performance compared to LZ4 and LZMA. The DEFLATE core format is
simple as well as easy to understand, therefore the code size of its
decompressor is small even for the bootloader use cases. The runtime
memory consumption is quite limited too (e.g. 32K + ~7K for each zlib
stream). As usual, EROFS ourperforms similar approaches too.
Alternatively, DEFLATE could still be used for some specific files
since EROFS supports multiple compression algorithms in one image.
[1] https://developer.apple.com/documentation/compression/compression_algorithm
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230810154859.118330-1-hsiangkao@linux.alibaba.com
Diffstat (limited to 'fs/erofs/Kconfig')
| -rw-r--r-- | fs/erofs/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index f259d92c9720..56a99ba8ce22 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -99,6 +99,21 @@ config EROFS_FS_ZIP_LZMA If unsure, say N. +config EROFS_FS_ZIP_DEFLATE + bool "EROFS DEFLATE compressed data support" + depends on EROFS_FS_ZIP + select ZLIB_INFLATE + help + Saying Y here includes support for reading EROFS file systems + containing DEFLATE compressed data. It gives better compression + ratios than the default LZ4 format, while it costs more CPU + overhead. + + DEFLATE support is an experimental feature for now and so most + file systems will be readable without selecting this option. + + If unsure, say N. + config EROFS_FS_ONDEMAND bool "EROFS fscache-based on-demand read support" depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y) |