bzip2/lzma: config and initramfs support for bzip2/lzma decompression

[linux-3.10.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index b3782c6d5ede57f94446de710213a2b20deed283..df84625b1373648f0224307f381c2ba24524e2e0 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -101,6 +101,56 @@ config LOCALVERSION_AUTO
 
          which is done within the script "scripts/setlocalversion".)
 
+choice
+        prompt "Kernel compression mode"
+        default KERNEL_GZIP
+        help
+         The linux kernel is a kind of self-extracting executable.
+         Several compression algorithms are available, which differ
+         in efficiency, compression and decompression speed.
+         Compression speed is only relevant when building a kernel.
+         Decompression speed is relevant at each boot.
+
+         If you have any problems with bzip2 or lzma compressed
+         kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
+         version of this functionality (bzip2 only), for 2.4, was
+         supplied by Christian Ludwig)
+
+         High compression options are mostly useful for users, who
+         are low on disk space (embedded systems), but for whom ram
+         size matters less.
+
+         If in doubt, select 'gzip'
+
+config KERNEL_GZIP
+       bool "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.
+
+config KERNEL_BZIP2
+       bool "Bzip2"
+       help
+         Its compression ratio and speed is intermediate.
+         Decompression speed is slowest among the 3.
+         The kernel size is about 10 per cent smaller with bzip2,
+         in comparison to gzip.
+         Bzip2 uses a large amount of memory. For modern kernels
+         you will need at least 8MB RAM or more for booting.
+
+config KERNEL_LZMA
+       bool "LZMA"
+       help
+         The most recent compression algorithm.
+        Its ratio is best, decompression speed is between the other
+        2. Compression is slowest.
+        The kernel size is about 33 per cent smaller with lzma,
+        in comparison to gzip.
+
+endchoice
+
+
 config SWAP
        bool "Support for paging of anonymous memory (swap)"
        depends on MMU && BLOCK
@@ -588,6 +638,13 @@ config KALLSYMS_ALL
 
           Say N.
 
+config KALLSYMS_STRIP_GENERATED
+       bool "Strip machine generated symbols from kallsyms"
+       depends on KALLSYMS_ALL
+       default y
+       help
+         Say N if you want kallsyms to retain even machine generated symbols.
+
 config KALLSYMS_EXTRA_PASS
        bool "Do an extra kallsyms pass"
        depends on KALLSYMS
@@ -938,10 +995,90 @@ source "block/Kconfig"
 config PREEMPT_NOTIFIERS
        bool
 
+choice
+       prompt "RCU Implementation"
+       default CLASSIC_RCU
+
 config CLASSIC_RCU
-       def_bool !PREEMPT_RCU
+       bool "Classic RCU"
        help
          This option selects the classic RCU implementation that is
          designed for best read-side performance on non-realtime
-         systems.  Classic RCU is the default.  Note that the
-         PREEMPT_RCU symbol is used to select/deselect this option.
+         systems.
+
+         Select this option if you are unsure.
+
+config TREE_RCU
+       bool "Tree-based hierarchical RCU"
+       help
+         This option selects the RCU implementation that is
+         designed for very large SMP system with hundreds or
+         thousands of CPUs.
+
+config PREEMPT_RCU
+       bool "Preemptible RCU"
+       depends on PREEMPT
+       help
+         This option reduces the latency of the kernel by making certain
+         RCU sections preemptible. Normally RCU code is non-preemptible, if
+         this option is selected then read-only RCU sections become
+         preemptible. This helps latency, but may expose bugs due to
+         now-naive assumptions about each RCU read-side critical section
+         remaining on a given CPU through its execution.
+
+endchoice
+
+config RCU_TRACE
+       bool "Enable tracing for RCU"
+       depends on TREE_RCU || PREEMPT_RCU
+       help
+         This option provides tracing in RCU which presents stats
+         in debugfs for debugging RCU implementation.
+
+         Say Y here if you want to enable RCU tracing
+         Say N if you are unsure.
+
+config RCU_FANOUT
+       int "Tree-based hierarchical RCU fanout value"
+       range 2 64 if 64BIT
+       range 2 32 if !64BIT
+       depends on TREE_RCU
+       default 64 if 64BIT
+       default 32 if !64BIT
+       help
+         This option controls the fanout of hierarchical implementations
+         of RCU, allowing RCU to work efficiently on machines with
+         large numbers of CPUs.  This value must be at least the cube
+         root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
+         systems and up to 262,144 for 64-bit systems.
+
+         Select a specific number if testing RCU itself.
+         Take the default if unsure.
+
+config RCU_FANOUT_EXACT
+       bool "Disable tree-based hierarchical RCU auto-balancing"
+       depends on TREE_RCU
+       default n
+       help
+         This option forces use of the exact RCU_FANOUT value specified,
+         regardless of imbalances in the hierarchy.  This is useful for
+         testing RCU itself, and might one day be useful on systems with
+         strong NUMA behavior.
+
+         Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
+
+         Say N if unsure.
+
+config TREE_RCU_TRACE
+       def_bool RCU_TRACE && TREE_RCU
+       select DEBUG_FS
+       help
+         This option provides tracing for the TREE_RCU implementation,
+         permitting Makefile to trivially select kernel/rcutree_trace.c.
+
+config PREEMPT_RCU_TRACE
+       def_bool RCU_TRACE && PREEMPT_RCU
+       select DEBUG_FS
+       help
+         This option provides tracing for the PREEMPT_RCU implementation,
+         permitting Makefile to trivially select kernel/rcupreempt_trace.c.