On Wed 25-03-20 18:26:34, Alexander Potapenko wrote:
> On Wed, Mar 25, 2020 at 5:19 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> >
> > On Wed 25-03-20 17:12:14, glider@xxxxxxxxxx wrote:
> > > This flag is to be used by KMSAN runtime to mark that newly created
> > > memory pages don't need KMSAN metadata backing them.
> >
> > I really dislike an idea of the gfp flag. If you need some form of
> > exclusion for kmsan allocations then follow the pattern of memalloc_no{fs,io}_{save,restore}
> > History tells us that single usecase gfp flags are too tempting to abuse
> > and using incorrectly.
>
> Great idea, will do!
> Guess PF_ flags isn't a scarce resource?
task_struct is a monster data structure and there are surely holes you
can fit your flag in. All you need is to just store it somewhere and
then check for it wherever you hook your infrastructure into the page
or slab allocator. The primary thing is to avoid a gfp flag.
Thanks!
--
Michal Hocko
SUSE Labs
