On Sunday, 18 February 2007 12:31, Oleg Nesterov wrote: > On 02/18, Rafael J. Wysocki wrote: > > > > On Sunday, 18 February 2007 00:47, Oleg Nesterov wrote: > > > > > > However, this means that sys_vfork() makes impossible to freeze processes > > > until child exits/execs. Not good. > > > > Yes, but this also is the current behavior. > > Yes, yes, I see. > > I forgot to say that we have another problem: coredumping. > > A thread which does do_coredump() send SIGKILL to ->mm users, and sleeps > on ->mm->core_startup_done. Now it can't be frozen if sub-thread goes to > refrigerator. I think this could be solved easily if we add a check to > refrigerator() as you suggested for ->vfork_donw. > > > I think the real solution would be to use an interruptible completion in the > > vfork code. It was discussed some time ago and, IIRC, Ingo had an > > experimental > > patch that implemented it. Still, for the suspend this really is not an > > issue > > in practice, so it wasn't merged. > > It is not (afaics) so trivial to do rightly, and with this change the parent > will be seen as TASK_INTERRUPTIBLE even without freezer in progress. > > A very vague idea: what if parent will do > > current->flags |= PF_PLEASE_CONSIDER_ME_AS_FROZEN_BUT_SET_TIF_FREEZE > wait_for_completion(&vfork); > try_to_freeze(); > > ?
This should work, but we'll need a separate process flag for it. If that's acceptable, I'd call it PF_VFORK_PARENT Greetings, Rafael - 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/
