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[PATCH] vmalloc: optimization, cleanup, bugfixes

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- 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>
This commit is contained in:
Eric Dumazet 2006-11-10 12:27:48 -08:00 committed by Linus Torvalds
parent 088406bcf6
commit 2b4ac44e7c
2 changed files with 15 additions and 14 deletions
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3
include/linux/vmalloc.h
View file

@ -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;
};
/*

26
mm/vmalloc.c
View file

@ -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);