On Thu, Apr 11, 2019 at 10:02:32PM +0200, Christian Brauner wrote: > On April 11, 2019 10:00:59 PM GMT+02:00, Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote: > >On Thu, Apr 11, 2019 at 01:50:42PM -0400, Joel Fernandes (Google) > >wrote: > >> pidfd are /proc/pid directory file descriptors referring to a task > >group > >> leader. Android low memory killer (LMK) needs pidfd polling support > >to > >> replace code that currently checks for existence of /proc/pid for > >> knowing a process that is signalled to be killed has died, which is > >both > >> racy and slow. The pidfd poll approach is race-free, and also allows > >the > >> LMK to do other things (such as by polling on other fds) while > >awaiting > >> the process being killed to die. > > > >It appears to me that the "pidfd" now will be an anon inode fd, and not > >based > >on /proc/, based on discussions with Linus. So I'll rework the patches > >accordingly. However that is relatively independent of this patch so > >this > >version can also be reviewed before I send out the reworked version. > > Thank you very much, Joel. > I'm off this week and traveling but I'll try to give it a look asap. > > Christian Sounds great to me, thanks a lot Christian. - Joel