[lkml]   [2018]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2] Document /proc/pid PID reuse behavior
On Wed, Nov 7, 2018 at 4:00 PM, Michal Hocko <> wrote:
> On Wed 07-11-18 15:48:20, Daniel Colascione wrote:
>> On Tue, Nov 6, 2018 at 1:05 PM, Michal Hocko <> wrote:
>> > otherwise anybody could simply DoS the system
>> > by consuming all available pids.
>> People can do that today using the instrument of terror widely known
>> as fork(2). The only thing standing between fork(2) and a full process
>> table is RLIMIT_NPROC.
> not really.

What else, besides memory consumption and (as you mention below)
cgroups? In practice, nobody uses RLIMIT_NPROC, so outside of various
container-y namespaced setups, avoidance of
system-DoS-through-PID-exhaustion isn't a pressing problem.

If you really do care about pid space depletion then you
> should use pid cgroup controller.

Or that, sure. But since cgroups are optional, the problem with the
core model remains. In general, if there's a problem X with the core
system API, and you can mitigate X by using a cgroup, X is still a

 \ /
  Last update: 2018-11-07 17:10    [W:0.176 / U:0.472 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site