[PATCH 1/3] procfs: Export next_tgid(), move it to kernel/pid.c

[Anton Vorontsov]

On Mon, Jan 30, 2012 at 02:43:12PM +0100, Oleg Nesterov wrote:
> On 01/30, Anton Vorontsov wrote:
> >
> > We'd like to use this function in the android low memory killer driver, so
> > let's export it.
> 
> I guess you mean 3/3.
> 
> If lowmem_shrink() can use next_tid() which is not really accurate,
> then why tou can't simply change it to use rcu_read_lock ?

Yes, in LMK driver we don't need to be accurate. I probably could use
rcu_read_lock, but the plan was in not holding any global locks (in
this case the rcu) at all, instead I'd like to hold just a reference
of the task, which the driver is analyzing at this time. Once we decide
(to kill or not to kill the task), we either send a signal (and drop
the reference) or just drop the reference.

Thanks,

-- 
Anton Vorontsov
Email: cbouatmailru at gmail.com