On Fri, Jul 07, 2017 at 11:42:09AM +0300, Igor Stoppa wrote: > On 06/07/17 19:27, Jerome Glisse wrote: > > On Wed, Jul 05, 2017 at 04:46:26PM +0300, Igor Stoppa wrote: [...] > > Yet another way is to use some of the free struct page fields ie > > when a page is allocated for vmalloc i think most of struct page > > fields are unuse (mapping, index, lru, ...). It would be better > > to use those rather than adding a page flag. > > Like introducing an unnamed union? Some sort of vmalloc_page_subtype? > If that is what you are proposing, I agree that it would work in a > similar fashion as what I have now, but without introducing the overhead > of the extra page flag. No need to introduce unamed union or anything. Just use one of the existing field for install you can make page->mapping point to the pmalloc pool structure. Or you can store a unique key value. I believe there is enough unuse field that for vmalloc pages that you should find one you can use. Just add some documentation in mm_types.h so people are aware of alternate use for the field you are using. Jérôme -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
