On Fri, May 10, 2019 at 09:36:12AM -0700, Matthew Wilcox wrote: > On Fri, May 10, 2019 at 10:12:40AM +0800, Huang, Ying wrote: > > > + nr_reclaimed += (1 << compound_order(page)); > > > > How about to change this to > > > > > > nr_reclaimed += hpage_nr_pages(page); > > Please don't. That embeds the knowledge that we can only swap out either > normal pages or THP sized pages. I'm trying to make the VM capable of > supporting arbitrary-order pages, and this would be just one more place > to fix. > > I'm sympathetic to the "self documenting" argument. My current tree has > a patch in it: > > mm: Introduce compound_nr > > Replace 1 << compound_order(page) with compound_nr(page). Minor > improvements in readability. > > It goes along with this patch: > > mm: Introduce page_size() > > It's unnecessarily hard to find out the size of a potentially huge page. > Replace 'PAGE_SIZE << compound_order(page)' with page_size(page). > > Better suggestions on naming gratefully received. I'm more happy with > page_size() than I am with compound_nr(). page_nr() gives the wrong > impression; page_count() isn't great either. Stupid question : what does 'nr' stand for? Ira
