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/mm/init_64.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index a02a14f0f32..6e7d5a42a09 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -54,6 +54,26 @@ static unsigned long dma_reserve __initdata; DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); +int direct_gbpages __meminitdata +#ifdef CONFIG_DIRECT_GBPAGES + = 1 +#endif +; + +static int __init parse_direct_gbpages_off(char *arg) +{ + direct_gbpages = 0; + return 0; +} +early_param("nogbpages", parse_direct_gbpages_off); + +static int __init parse_direct_gbpages_on(char *arg) +{ + direct_gbpages = 1; + return 0; +} +early_param("gbpages", parse_direct_gbpages_on); + /* * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the * physical space so we can cache the place of the first one and move -- cgit v1.2.3-70-g09d2