From: Eric Dumazet - 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. Signed-off-by: Eric Dumazet Cc: Nick Piggin Signed-off-by: Andrew Morton --- include/linux/vmalloc.h | 3 ++- mm/vmalloc.c | 28 +++++++++++++++------------- 2 files changed, 17 insertions(+), 14 deletions(-) diff -puN include/linux/vmalloc.h~vmalloc-optimization-cleanup-bugfixes include/linux/vmalloc.h --- a/include/linux/vmalloc.h~vmalloc-optimization-cleanup-bugfixes +++ a/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 -puN mm/vmalloc.c~vmalloc-optimization-cleanup-bugfixes mm/vmalloc.c --- a/mm/vmalloc.c~vmalloc-optimization-cleanup-bugfixes +++ a/mm/vmalloc.c @@ -186,10 +186,8 @@ static struct vm_struct *__get_vm_area_n if (unlikely(!area)) return NULL; - if (unlikely(!size)) { - kfree (area); + if (unlikely(!size)) return NULL; - } /* * We always allocate a guard page. @@ -532,11 +530,13 @@ 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); + BUG_ON(!area); + area->flags |= VM_USERMAP; + write_unlock(&vmlist_lock); + } return ret; } EXPORT_SYMBOL(vmalloc_user); @@ -605,11 +605,13 @@ 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); + BUG_ON(!area); + area->flags |= VM_USERMAP; + write_unlock(&vmlist_lock); + } return ret; } EXPORT_SYMBOL(vmalloc_32_user); _