X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2FKconfig.cpu;h=e09a6b73a1aab5c3fc6a353e22af4936b047416f;hb=b297d520b9af536d5580ac505dd316be4cf5560c;hp=018d68e3184e029b4ad85d771a6bf308cd7f9799;hpb=96daa8cd53945a1220d2b2f4a44bc57f0cc46760;p=linux-2.6

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 018d68e318..e09a6b73a1 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -321,8 +321,17 @@ config X86_XADD
 	depends on X86_32 && !M386
 
 config X86_PPRO_FENCE
-	def_bool y
+	bool "PentiumPro memory ordering errata workaround"
 	depends on M686 || M586MMX || M586TSC || M586 || M486 || M386 || MGEODEGX1
+	help
+	  Old PentiumPro multiprocessor systems had errata that could cause memory
+	  operations to violate the x86 ordering standard in rare cases. Enabling this
+	  option will attempt to work around some (but not all) occurances of
+	  this problem, at the cost of much heavier spinlock and memory barrier
+	  operations.
+
+	  If unsure, say n here. Even distro kernels should think twice before enabling
+	  this: there are few systems, and an unlikely bug.
 
 config X86_F00F_BUG
 	def_bool y