Re: [PATCH 4/6] mm: introduce page->dma_pinned_flags, _count

From: Michal Hocko
Date: Wed Oct 17 2018 - 07:09:59 EST


On Tue 16-10-18 18:48:23, John Hubbard wrote:
[...]
> It's hard to say exactly what the active/inactive/unevictable list should
> be when DMA is done and put_user_page*() is called, because we don't know
> if some device read, wrote, or ignored any of those pages. Although if
> put_user_pages_dirty() is called, that's an argument for "active", at least.

Any reason to not use putback_lru_page?

Please note I haven't really got through your patches to have a wider
picture of the change so this is just hint for the LRU part of the
issue.
--
Michal Hocko
SUSE Labs