Re: [PATCH] mm, memcg: fix reclaim deadlock with writeback

From: Jan Kara
Date: Tue Dec 11 2018 - 11:39:56 EST

On Tue 11-12-18 17:21:49, Michal Hocko wrote:
> On Tue 11-12-18 18:15:42, Kirill A. Shutemov wrote:
> > For instance, DAX page fault will setup page table entry on its own and
> > return VM_FAULT_NOPAGE. It uses vmf_insert_mixed() to setup the page table
> > and ignores your pre-allocated page table.
> Does this happen with a page locked and with __GFP_ACCOUNT allocation. I
> am not familiar with that code but I do not see it from a quick look.

DAX has no page to lock and also no writeback to do so the deadlock isn't
really possible when DAX is in use...

Jan Kara <jack@xxxxxxxx>