On 09/15, Guillaume Chazarain wrote: > > Le Thu, 13 Sep 2007 16:41:41 +0400, > Oleg Nesterov <[EMAIL PROTECTED]> a ??crit : > > > > + do > > > + if (!tsk->exit_state) > > > + add_tsk(stats, tsk); > > > + while_each_thread(first, tsk); > > > > This reminds me. The "!tsk->exit_state" is not good and racy, it > > can't prevent the double accounting (of course, I don't blame this > > patch). > > I documented this in v4, but I was wondering if always setting > tsk->exit_state under the protection of lock_task_sighand() would fix > the race.
No, this is not enough. There is a window between do_exit()->taskstats_exit() and do_exit()->exit_notify() which sets ->exit_state. Probably, we can shift taskstats_exit() into exit_notify() but this is not good. Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
