x86: Support compiling out human-friendly processor feature names

The table mapping CPUID bits to human-readable strings takes up a
non-trivial amount of space, and only exists to support /proc/cpuinfo
and a couple of kernel messages.  Since programs depend on the format of
/proc/cpuinfo, force inclusion of the table when building with /proc
support; otherwise, support omitting that table to save space, in which
case the kernel messages will print features numerically instead.

In addition to saving 1408 bytes out of vmlinux, this also saves 1373
bytes out of the uncompressed setup code, which contributes directly to
the size of bzImage.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5d0bf1a..a11f27c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -136,6 +136,7 @@ config X86
 	select HAVE_ACPI_APEI if ACPI
 	select HAVE_ACPI_APEI_NMI if ACPI
 	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
+	select X86_FEATURE_NAMES if PROC_FS
 
 config INSTRUCTION_DECODER
 	def_bool y
@@ -313,6 +314,17 @@ config SMP
 
 	  If you don't know what to do here, say N.
 
+config X86_FEATURE_NAMES
+	bool "Processor feature human-readable names" if EMBEDDED
+	default y
+	---help---
+	  This option compiles in a table of x86 feature bits and corresponding
+	  names.  This is required to support /proc/cpuinfo and a few kernel
+	  messages.  You can disable this to save space, at the expense of
+	  making those few kernel messages show numeric feature bits instead.
+
+	  If in doubt, say Y.
+
 config X86_X2APIC
 	bool "Support x2apic"
 	depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP