On Sun, Aug 15, 2021 at 07:50:57PM +0800, Mianhan Liu wrote: > nr_free_buffer_pages could be exposed through mm.h instead of swap.h. > The advantage of this change is that it can reduce the obsolete includes. > For example, net/ipv4/tcp.c wouldn't need swap.h any more since it has > already included mm.h. > Moreover, after preprocessing all the files that use nr_free_buffer_pages, > it turns out that those files have already included mm.h. > Thus, we can move nr_free_buffer_pages from swap.h to mm.h safely. This change > will not affect the compilation of other files. In general, we're trying to move in the other direction; move things out of mm.h and reduce the number of files which include mm.h. That said, I don't see what nr_free_buffer_pages() has to do with the rest of swap.h, so I'm OK with moving this over. That said, there are a number of other files which should have swap.h removed. eg: drivers/mmc/core/mmc_test.c:#include <linux/swap.h> /* For nr_free_buffer_pages() */ and it would be good to check the other files which use nr_free_buffer_pages() to see if they can have swap.h removed too. > +++ b/include/linux/mm.h > @@ -871,6 +871,7 @@ void put_pages_list(struct list_head *pages); > void split_page(struct page *page, unsigned int order); > void folio_copy(struct folio *dst, struct folio *src); > > +extern unsigned long nr_free_buffer_pages(void); Please remove the 'extern' while you're moving this. > +++ b/net/ipv4/tcp.c If you're interested in cleaning up the headers, it'd be nice if less of the networking code depended on pagemap.h ...
