Alan Cox <alan at lxorguk.ukuu.org.uk> writes: > Ar Maw, 2006-08-15 am 12:23 -0600, ysgrifennodd Eric W. Biederman: >> This keeps the wrong process from being notified if the >> daemon to spawn a new console dies. > > Not sure why we count pids not task structs but within the proposed > implementation this appears correct so Basically struct pid is relatively cheap, 64bytes or so. struct task is expensive 10K or so, when all of the stacks and everything are included. Counting pids allows the task to exit in user space and free up all of it's memory. When /proc used to count the task struct it was fairly easy to deliberately oom a 32bit machine just by open up directories in /proc and then having the process exit. rlimits didn't help because we don't count processes that have exited. > > Acked-by: Alan Cox <alan at redhat.com> Thanks. When I get to the tty portion of this I think I am going to have to synchronize with you as last I looked you were working in this area as well. Eric
