On Tue, Sep 15, 2015 at 01:36:45PM -0400, Sasha Levin wrote: > On 09/11/2015 09:27 PM, Hugh Dickins wrote: > > I'm inclined to echo Vlastimil's comment from earlier in the thread: > > sounds like an overkill, unless we find something more serious than this. > > I've modified my tests to stress the exit path of processes with many vmas, Could you share the test? > and hit the following NULL ptr deref (not sure if it's related to the original issue): > > [1181047.935563] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN > [1181047.937223] Modules linked in: > [1181047.937772] CPU: 4 PID: 21912 Comm: trinity-c341 Not tainted 4.3.0-rc1-next-20150914-sasha-00043-geddd763-dirty #2554 > [1181047.939387] task: ffff8804195c8000 ti: ffff880433f00000 task.ti: ffff880433f00000 > [1181047.940533] RIP: unmap_vmas (mm/memory.c:1337) Is it "struct mm_struct *mm = vma->vm_mm;"? -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>