On Wed, Mar 18, 2020 at 01:42:50AM +0800, Yang Shi wrote: > v3: * Fixed the build error reported by lkp. I'm not terribly enthusiastic about including pagemap.h from swap.h. It's a discussion that reasonable people can disagree about, so let's set it up: This patch adds inline bool page_evictable(struct page *page) to swap.h. page_evictable() uses mapping_evictable() which is in pagemap.h. mapping_evictable() uses AS_UNEVICTABLE which is also in pagemap.h. We could move mapping_evictable() and friends to fs.h (already included by swap.h). But how about just moving page_evictable() to pagemap.h? pagemap.h is already included by mm/mlock.c, mm/swap.c and mm/vmscan.c, which are the only three current callers of page_evictable(). In fact, since it's only called by those three files, perhaps it should be in mm/internal.h? I don't see it becoming a terribly popular function to call outside of the core mm code. I think I have a mild preference for it being in pagemap.h, since I don't have a hard time convincing myself that it's part of the page cache API, but I definitely prefer internal.h over swap.h.
