From 2b4ac44e7c7e16cf9411b81693ff3e604f332bf1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet 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 Cc: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 dc9a29d84ab..924e502905d 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 46606c133e8..7dc6aa74516 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); -- 2.41.1