Messages in this thread | | | Date | Fri, 27 Feb 2015 14:35:39 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH RFC 0/2] add nproc cgroup subsystem |
| |
Hello, Austin.
On Fri, Feb 27, 2015 at 01:49:53PM -0500, Austin S Hemmelgarn wrote: > As far as being trivial to achieve, I'm assuming you are referring to rlimit > and PAM's limits module, both of which have their own issues. Using > pam_limits.so to limit processes isn't trivial because it requires calling > through PAM to begin with, which almost no software that isn't login related > does, and rlimits are tricky to set up properly with the granularity that > having a cgroup would provide. ... > PID's are a fundamental resource, you run out and it's an only marginally > better situation than OOM, namely, if you don't already have a shell open > which has kill builtin (because you can't fork), or have some other reliable > way to terminate processes without forking, you are stuck either waiting for > the problem to resolve itself, or have to reset the system.
Right, this is an a lot more valid argument. Currently, we're capping max pid at 4M which translates to some tens of gigs of memory which isn't a crazy amount on modern machines. The hard(er) barrier would be around 2^30 (2^29 from futex side, apparently) which would also be reacheable on configurations w/ terabytes of memory.
I'll think more about it and get back.
Thanks a lot.
-- tejun
| |