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@joelfernandes.org 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