On Wed 07-11-18 15:48:20, Daniel Colascione wrote: > On Tue, Nov 6, 2018 at 1:05 PM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > On Mon 05-11-18 13:22:05, Daniel Colascione wrote: > >> State explicitly that holding a /proc/pid file descriptor open does > >> not reserve the PID. Also note that in the event of PID reuse, these > >> open file descriptors refer to the old, now-dead process, and not the > >> new one that happens to be named the same numeric PID. > > > > This sounds quite obvious > > Many people *on* *LKML* were wrong about this behavior. If it's not > obvious to experienced kernel developers, it's certainly not obvious > to the public. Fair enough > > 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. If you really do care about pid space depletion then you should use pid cgroup controller. -- Michal Hocko SUSE Labs
