On Fri, 15 Apr 2016, Michal Hocko wrote:
> On Fri 15-04-16 08:29:28, Mikulas Patocka wrote: > > > > > > On Mon, 11 Apr 2016, Michal Hocko wrote: > > > > > From: Michal Hocko <[email protected]> > > > > > > copy_params seems to be little bit confused about which allocation flags > > > to use. It enforces GFP_NOIO even though it uses > > > memalloc_noio_{save,restore} which enforces GFP_NOIO at the page > > > > memalloc_noio_{save,restore} is used because __vmalloc is flawed and > > doesn't respect GFP_NOIO properly (it doesn't use gfp flags when > > allocating pagetables). > > Yes and there are no plans to change __vmalloc to properly propagate gfp > flags through the whole call chain and that is why we have > memalloc_noio thingy. If that ever changes later the GFP_NOIO can be > added in favor of memalloc_noio API. Both are clearly redundant. > -- > Michal Hocko > SUSE Labs You could move memalloc_noio_{save,restore} to __vmalloc. Something like if (!(gfp_mask & __GFP_IO)) noio_flag = memalloc_noio_save(); ... if (!(gfp_mask & __GFP_IO)) memalloc_noio_restore(noio_flag); That would be better than repeating this hack in every __vmalloc caller that need GFP_NOIO. Mikulas
