[Containers] [PATCH 6/7] vt: Update spawnpid to be a struct
pid_t
Eric W. Biederman
ebiederm at xmission.com
Tue Aug 15 11:45:09 PDT 2006
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
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