From a0d40c80256e31b23849f2ba781b74bf0218a1fa Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 26 Mar 2010 15:28:51 -0700 Subject: [PATCH] vmap: add flag to allow lazy unmap to be disabled at runtime Add a flag to force lazy_max_pages() to zero to prevent any outstanding mapped pages. We'll need this for Xen. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Konrad Rzeszutek Wilk Acked-by: Nick Piggin --- include/linux/vmalloc.h | 2 ++ mm/vmalloc.c | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 227c2a585e4f..b840fdaf438c 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -7,6 +7,8 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */ +extern bool vmap_lazy_unmap; + /* bits in flags of vmalloc's vm_struct below */ #define VM_IOREMAP 0x00000001 /* ioremap() and friends */ #define VM_ALLOC 0x00000002 /* vmalloc() */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ae007462b7f6..7f35fe2cf9e7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -31,6 +31,7 @@ #include #include +bool vmap_lazy_unmap __read_mostly = true; /*** Page table manipulation functions ***/ @@ -502,6 +503,9 @@ static unsigned long lazy_max_pages(void) { unsigned int log; + if (!vmap_lazy_unmap) + return 0; + log = fls(num_online_cpus()); return log * (32UL * 1024 * 1024 / PAGE_SIZE);