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Commit 2b4ac44e authored by Eric Dumazet's avatar Eric Dumazet Committed by Linus Torvalds
Browse files

[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: default avatarEric Dumazet <dada1@cosmosbay.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 088406bc

include/linux/vmalloc.h

+2 −1
Original line number Diff line number Diff line
@@ -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;

};



/*

mm/vmalloc.c

+13 −13
Original line number Diff line number Diff line
@@ -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);

	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);

	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);