diff options
| author | Bertrand Jacquin | 2014-08-27 20:31:56 +0930 |
|---|---|---|
| committer | Rusty Russell | 2014-08-27 21:54:12 +0930 |
| commit | beb50df39e91745604ce3cb9dc6a503f39f4383d (patch) | |
| tree | eaa6a996228eb532f56f46d1b5004a10062ac4fa /Makefile | |
| parent | 40e42f6a2596bbe757e561d4806fadd924f8c9fd (diff) | |
kbuild: handle module compression while running 'make modules_install'.
Since module-init-tools (gzip) and kmod (gzip and xz) support compressed
modules, it could be useful to include a support for compressing modules
right after having them installed. Doing this in kbuild instead of per
distro can permit to make this kind of usage more generic.
This patch add a Kconfig entry to "Enable loadable module support" menu
and let you choose to compress using gzip (default) or xz.
Both gzip and xz does not used any extra -[1-9] option since Andi Kleen
and Rusty Russell prove no gain is made using them. gzip is called with -n
argument to avoid storing original filename inside compressed file, that
way we can save some more bytes.
On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a
total of 378MB (no strip, no sign, no compress), the following table
shows observed disk space gain based on the allmodconfig .config :
| time |
+-------------+-----------------+
| manual .ko | make | size | percent
| compression | modules_install | | gain
+-------------+-----------------+------+--------
- | | 18.61s | 378M |
GZIP | 3m16s | 3m37s | 102M | 73.41%
XZ | 5m22s | 5m39s | 77M | 79.83%
The gain for restricted environnement seems to be interesting while
uncompress can be time consuming but happens only while loading a module,
that is generally done only once.
This is fully compatible with signed modules while the signed module is
compressed. module-init-tools or kmod handles decompression
and provide to other layer the uncompressed but signed payload.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Bertrand Jacquin <beber@meleeweb.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -842,6 +842,21 @@ mod_strip_cmd = true endif # INSTALL_MOD_STRIP export mod_strip_cmd +# CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed +# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP +# or CONFIG_MODULE_COMPRESS_XZ. + +mod_compress_cmd = true +ifdef CONFIG_MODULE_COMPRESS + ifdef CONFIG_MODULE_COMPRESS_GZIP + mod_compress_cmd = gzip -n + endif # CONFIG_MODULE_COMPRESS_GZIP + ifdef CONFIG_MODULE_COMPRESS_XZ + mod_compress_cmd = xz + endif # CONFIG_MODULE_COMPRESS_XZ +endif # CONFIG_MODULE_COMPRESS +export mod_compress_cmd + # Select initial ramdisk compression format, default is gzip(1). # This shall be used by the dracut(8) tool while creating an initramfs image. # |