Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa...

[cascardo/linux.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index 41066e4..44f9ed3 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -783,8 +783,13 @@ endchoice
 
 endmenu # "RCU Subsystem"
 
+config BUILD_BIN2C
+       bool
+       default n
+
 config IKCONFIG
        tristate "Kernel .config support"
+       select BUILD_BIN2C
        ---help---
          This option enables the complete Linux kernel ".config" file
          contents to be saved in the kernel. It provides documentation
@@ -807,15 +812,53 @@ config LOG_BUF_SHIFT
        range 12 21
        default 17
        help
-         Select kernel log buffer size as a power of 2.
+         Select the minimal kernel log buffer size as a power of 2.
+         The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
+         parameter, see below. Any higher size also might be forced
+         by "log_buf_len" boot parameter.
+
          Examples:
-                    17 => 128 KB
+                    17 => 128 KB
                     16 => 64 KB
-                    15 => 32 KB
-                    14 => 16 KB
+                    15 => 32 KB
+                    14 => 16 KB
                     13 =>  8 KB
                     12 =>  4 KB
 
+config LOG_CPU_MAX_BUF_SHIFT
+       int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
+       range 0 21
+       default 12 if !BASE_SMALL
+       default 0 if BASE_SMALL
+       help
+         This option allows to increase the default ring buffer size
+         according to the number of CPUs. The value defines the contribution
+         of each CPU as a power of 2. The used space is typically only few
+         lines however it might be much more when problems are reported,
+         e.g. backtraces.
+
+         The increased size means that a new buffer has to be allocated and
+         the original static one is unused. It makes sense only on systems
+         with more CPUs. Therefore this value is used only when the sum of
+         contributions is greater than the half of the default kernel ring
+         buffer as defined by LOG_BUF_SHIFT. The default values are set
+         so that more than 64 CPUs are needed to trigger the allocation.
+
+         Also this option is ignored when "log_buf_len" kernel parameter is
+         used as it forces an exact (power of two) size of the ring buffer.
+
+         The number of possible CPUs is used for this computation ignoring
+         hotplugging making the compuation optimal for the the worst case
+         scenerio while allowing a simple algorithm to be used from bootup.
+
+         Examples shift values and their meaning:
+                    17 => 128 KB for each CPU
+                    16 =>  64 KB for each CPU
+                    15 =>  32 KB for each CPU
+                    14 =>  16 KB for each CPU
+                    13 =>   8 KB for each CPU
+                    12 =>   4 KB for each CPU
+
 #
 # Architectures with an unreliable sched_clock() should select this:
 #