On Tue 20-11-18 17:17:00, Kirill A. Shutemov wrote: > On Tue, Nov 20, 2018 at 03:12:07PM +0100, Michal Hocko wrote: > > On Tue 20-11-18 17:07:15, Kirill A. Shutemov wrote: > > > On Tue, Nov 20, 2018 at 02:43:23PM +0100, Michal Hocko wrote: > > > > From: Michal Hocko <mhocko@xxxxxxxx> > > > > > > > > filemap_map_pages takes a speculative reference to each page in the > > > > range before it tries to lock that page. While this is correct it > > > > also can influence page migration which will bail out when seeing > > > > an elevated reference count. The faultaround code would bail on > > > > seeing a locked page so we can pro-actively check the PageLocked > > > > bit before page_cache_get_speculative and prevent from pointless > > > > reference count churn. > > > > > > Looks fine to me. > > > > Thanks for the review. > > > > > But please drop a line of comment in the code. As is it might be confusing > > > for a reader. > > > > This? > > Yep. > > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cool, thanks! I will wait some more time for review feedback for other patches and then repost with this folded in. -- Michal Hocko SUSE Labs
