Messages in this thread Patch in this message | | | From | Wanpeng Li <> | Subject | [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation | Date | Tue, 3 Sep 2013 15:01:46 +0800 |
| |
There is a race window between vmap_area free and show vmap_area information.
A B
remove_vm_area spin_lock(&vmap_area_lock); va->flags &= ~VM_VM_AREA; spin_unlock(&vmap_area_lock); spin_lock(&vmap_area_lock); if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) return 0; if (!(va->flags & VM_VM_AREA)) { seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", (void *)va->va_start, (void *)va->va_end, va->va_end - va->va_start); return 0; } free_unmap_vmap_area(va); flush_cache_vunmap free_unmap_vmap_area_noflush unmap_vmap_area free_vmap_area_noflush va->flags |= VM_LAZY_FREE
The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and keep not dump vm_map_ram allocation information as the logic before that commit.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> --- mm/vmalloc.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 5368b17..62b7932 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) return 0; - if (!(va->flags & VM_VM_AREA)) { - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", - (void *)va->va_start, (void *)va->va_end, - va->va_end - va->va_start); - return 0; - } - v = va->vm; seq_printf(m, "0x%pK-0x%pK %7ld", -- 1.8.1.2
| |