On Thu, Apr 05, 2018 at 08:56:50PM +0200, Michal Hocko wrote: > On Thu 05-04-18 21:26:51, Cyrill Gorcunov wrote: > > An ability to manipulate mm_struct fields was introduced in > > sake of CRIU in first place. Later we provide more suitable > > and safe operation PR_SET_MM_MAP where all fields to be modifed > > are passed in one structure which allows us to make more detailed > > verification. > > I hope this will serve as a memento for future single-user APIs > proposals. The whole thing was a bad idea since the beginning.
It wasn't a bad idea at all, kernel evolves with time and the first version of the api served as it should (actually a number of things get involved like user-namespaces, mm reworks and such things). So no, it wasn't bad. Rather to make it more suitable we provided a second version of the api. > > Still old interface remains present for compatibility reason > > though CRIU itself already switched to PR_SET_MM_MAP on its > > own long ago. > > > > Googling didn't reveal some other users of this operation > > so I think it should be safe to remove this interface. > > > > v2: > > - Improve warning message > > - Drop redundant args check > > > > CC: Andrey Vagin <ava...@openvz.org> > > CC: Andrew Morton <a...@linuxfoundation.org> > > CC: Pavel Emelyanov <xe...@virtuozzo.com> > > CC: Michael Kerrisk <mtk.manpa...@gmail.com> > > CC: Yang Shi <yang....@linux.alibaba.com> > > CC: Michal Hocko <mho...@kernel.org> > > Signed-off-by: Cyrill Gorcunov <gorcu...@gmail.com> > > Acked-by: Michal Hocko <mho...@suse.com> > > and fingers crossed that we haven't grown other users outside of CRIU > which is quite bound to specific kernels AFAIK. Surely.
