From 2b4ac44e7c7e16cf9411b81693ff3e604f332bf1 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 10 Nov 2006 12:27:48 -0800
Subject: [PATCH] [PATCH] vmalloc: optimization, cleanup, bugfixes
- reorder 'struct vm_struct' to speedup lookups on CPUS with small cache
lines. The fields 'next,addr,size' should be now in the same cache line,
to speedup lookups.
- One minor cleanup in __get_vm_area_node()
- Bugfixes in vmalloc_user() and vmalloc_32_user() NULL returns from
__vmalloc() and __find_vm_area() were not tested.
[akpm@osdl.org: remove redundant BUG_ONs]
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
include/linux/vmalloc.h | 3 ++-
mm/vmalloc.c | 26 +++++++++++++-------------
2 files changed, 15 insertions(+), 14 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index dc9a29d84abc..924e502905d4 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -23,13 +23,14 @@ struct vm_area_struct;
#endif
struct vm_struct {
+ /* keep next,addr,size together to speedup lookups */
+ struct vm_struct *next;
void *addr;
unsigned long size;
unsigned long flags;
struct page **pages;
unsigned int nr_pages;
unsigned long phys_addr;
- struct vm_struct *next;
};
/*
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 46606c133e82..7dc6aa745166 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -186,10 +186,8 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long fl
if (unlikely(!area))
return NULL;
- if (unlikely(!size)) {
- kfree (area);
+ if (unlikely(!size))
return NULL;
- }
/*
* We always allocate a guard page.
@@ -532,11 +530,12 @@ void *vmalloc_user(unsigned long size)
void *ret;
ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
- write_lock(&vmlist_lock);
- area = __find_vm_area(ret);
- area->flags |= VM_USERMAP;
- write_unlock(&vmlist_lock);
-
+ if (ret) {
+ write_lock(&vmlist_lock);
+ area = __find_vm_area(ret);
+ area->flags |= VM_USERMAP;
+ write_unlock(&vmlist_lock);
+ }
return ret;
}
EXPORT_SYMBOL(vmalloc_user);
@@ -605,11 +604,12 @@ void *vmalloc_32_user(unsigned long size)
void *ret;
ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
- write_lock(&vmlist_lock);
- area = __find_vm_area(ret);
- area->flags |= VM_USERMAP;
- write_unlock(&vmlist_lock);
-
+ if (ret) {
+ write_lock(&vmlist_lock);
+ area = __find_vm_area(ret);
+ area->flags |= VM_USERMAP;
+ write_unlock(&vmlist_lock);
+ }
return ret;
}
EXPORT_SYMBOL(vmalloc_32_user);