From 00d1c5e05736f947687be27706bda01cec104e57 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 17 Apr 2008 17:40:45 +0200 Subject: x86: add gbpages switches These new controls toggle experimental support for a new CPU feature, the straightforward extension of largepages from the pmd level to the pud level, which allows 1GB (kernel) TLBs instead of 2MB TLBs. Turn it off by default, as this code has not been tested well enough yet. Use the CONFIG_DIRECT_GBPAGES=y .config option or gbpages on the boot line can be used to enable it. If enabled in the .config then nogbpages boot option disables it. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/x86/Kconfig.debug') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 7ce8e702566..f4413c04e68 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -76,6 +76,18 @@ config DEBUG_RODATA data. This is recommended so that we can catch kernel bugs sooner. If in doubt, say "Y". +config DIRECT_GBPAGES + bool "Enable gbpages-mapped kernel pagetables" + depends on DEBUG_KERNEL && EXPERIMENTAL && X86_64 + help + Enable gigabyte pages support (if the CPU supports it). This can + improve the kernel's performance a tiny bit by reducing TLB + pressure. + + This is experimental code. + + If in doubt, say "N". + config DEBUG_RODATA_TEST bool "Testcase for the DEBUG_RODATA feature" depends on DEBUG_RODATA -- cgit v1.2.3-18-g5258