[PATCH 5/9] vmap: add flag to allow lazy unmap to be disabled at runtime
From: Konrad Rzeszutek Wilk
Date: Tue Jul 27 2010 - 13:21:09 EST
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
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 <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Acked-by: Nick Piggin <npiggin@xxxxxxx>
---
include/linux/vmalloc.h | 2 ++
mm/vmalloc.c | 4 ++++
2 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 227c2a5..b840fda 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 ae00746..7f35fe2 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -31,6 +31,7 @@
#include <asm/tlbflush.h>
#include <asm/shmparam.h>
+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);
--
1.7.0.1
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