On Wed, Feb 13, 2019 at 03:04:51PM -0800, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > To facilitate additional options to get_user_pages_fast() change the > singular write parameter to be gup_flags. So now we have: long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); and int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages) Does this make any sense? At least the arguments should be in the same order, I think. Also this comment: /* * get_user_pages_unlocked() is suitable to replace the form: * * down_read(&mm->mmap_sem); * get_user_pages(tsk, mm, ..., pages, NULL); * up_read(&mm->mmap_sem); * * with: * * get_user_pages_unlocked(tsk, mm, ..., pages); * * It is functionally equivalent to get_user_pages_fast so * get_user_pages_fast should be used instead if specific gup_flags * (e.g. FOLL_FORCE) are not required. */ Needs some attention as the recommendation is now nonsense. Honestly a proper explanation of why two functions exist would be great at this point :) Jason _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
