Re: [next-20160615] kernel BUG at mm/rmap.c:1251!

[Minchan Kim]

On Thu, Jun 16, 2016 at 06:54:57PM +0900, Sergey Senozhatsky wrote:
> On (06/16/16 11:41), Michal Hocko wrote:
> > On Thu 16-06-16 18:23:45, Sergey Senozhatsky wrote:
> > > On (06/16/16 10:58), Michal Hocko wrote:
> > > > > [..]
> > > > > [  272.687656] vma ffff8800b855a5a0 start 00007f3576d58000 end 00007f3576f66000
> > > > >                next ffff8800b977d2c0 prev ffff8800bdfb1860 mm ffff8801315ff200
> > > > >                prot 8000000000000025 anon_vma ffff8800b7e583b0 vm_ops           (null)
> > > > >                pgoff 7f3576d58 file           (null) private_data           (null)
> > > > >                flags: 0x100073(read|write|mayread|maywrite|mayexec|account)
> > > > > [  272.691793] ------------[ cut here ]------------
> > > > > [  272.692820] kernel BUG at mm/rmap.c:1251!
> > > > 
> > > > Is this?
> > > > page_add_new_anon_rmap:
> > > > 	VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma)
> > > > [...]
> > > 
> > > I think it is
> > > 
> > > 1248 void page_add_new_anon_rmap(struct page *page,
> > > 1249         struct vm_area_struct *vma, unsigned long address, bool compound)
> > > 1250 {
> > > 1251         int nr = compound ? hpage_nr_pages(page) : 1;
> > > 1252
> > > 1253         VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
> > > 1254         __SetPageSwapBacked(page);
> > > 
> > > > > [  272.727842] BUG: sleeping function called from invalid context at include/linux/sched.h:2960
> > > > 
> > > > If yes then I am not sure we can do much about the this part. BUG_ON in
> > > > an atomic context is unfortunate but the BUG_ON points out a real bug so
> > > > we shouldn't drop it because of the potential atomic context. The above
> > > > VM_BUG_ON should definitely be addressed. I thought that Vlastimil has
> > > > pointed out some issues with the khugepaged lock inconsistencies which
> > > > might lead to issues like this.
> > > 
> > > collapse_huge_page() ->mmap_sem fixup patch (http://marc.info/?l=linux-mm&m=146495692807404&w=2)
> > > is in next-20160615. or do you mean some other patch?
> > 
> > Yes that's what I meant, but I haven't reviewed the patch to see whether
> > it is correct/complete. It would be good to see whether the issue is
> > related to those changes.
> 
> I'll copy-paste one more backtrace I swa today [originally was posted to another
> mail thread].

Please, look at 20160616100932.GS17127@bbox">http://lkml.kernel.org/r/20160616100932.GS17127@bbox