diff options
Diffstat (limited to 'init/Kconfig')
| -rw-r--r-- | init/Kconfig | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/init/Kconfig b/init/Kconfig index 54c655ce9c0..d95ca7cd5d4 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -115,10 +115,13 @@ config HAVE_KERNEL_BZIP2 config HAVE_KERNEL_LZMA bool +config HAVE_KERNEL_LZO + bool + choice prompt "Kernel compression mode" default KERNEL_GZIP - depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA + depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO help The linux kernel is a kind of self-extracting executable. Several compression algorithms are available, which differ @@ -141,9 +144,8 @@ config KERNEL_GZIP bool "Gzip" depends on HAVE_KERNEL_GZIP help - The old and tried gzip compression. Its compression ratio is - the poorest among the 3 choices; however its speed (both - compression and decompression) is the fastest. + The old and tried gzip compression. It provides a good balance + between compression ratio and decompression speed. config KERNEL_BZIP2 bool "Bzip2" @@ -164,6 +166,14 @@ config KERNEL_LZMA two. Compression is slowest. The kernel size is about 33% smaller with LZMA in comparison to gzip. +config KERNEL_LZO + bool "LZO" + depends on HAVE_KERNEL_LZO + help + Its compression ratio is the poorest among the 4. The kernel + size is about about 10% bigger than gzip; however its speed + (both compression and decompression) is the fastest. + endchoice config SWAP @@ -1079,6 +1089,28 @@ config SLOB endchoice +config MMAP_ALLOW_UNINITIALIZED + bool "Allow mmapped anonymous memory to be uninitialized" + depends on EMBEDDED && !MMU + default n + help + Normally, and according to the Linux spec, anonymous memory obtained + from mmap() has it's contents cleared before it is passed to + userspace. Enabling this config option allows you to request that + mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus + providing a huge performance boost. If this option is not enabled, + then the flag will be ignored. + + This is taken advantage of by uClibc's malloc(), and also by + ELF-FDPIC binfmt's brk and stack allocator. + + Because of the obvious security issues, this option should only be + enabled on embedded devices where you control what is run in + userspace. Since that isn't generally a problem on no-MMU systems, + it is normally safe to say Y here. + + See Documentation/nommu-mmap.txt for more information. + config PROFILING bool "Profiling support (EXPERIMENTAL)" help |