Hi Jan, On Wed, 2010-06-09 at 17:18 +0200, ext Jan Engelhardt wrote: > On Wednesday 2010-06-09 17:11, Luciano Coelho wrote: > >Do you think it's okay to leave it like this for now and extend it for > >multiple namespace support with a future patch? > > Yes. Least thing we need is one humongous patch. :) Thanks! That was my concern too. One huge and very complex patch is not a nice thing to have. ;) > >> > + timer = __idletimer_tg_find_by_label(info->label); > >> > + if (!timer) { > >> > + spin_unlock(&list_lock); > >> > + timer = idletimer_tg_create(info); > >> > > >> > >> How does this prevent creating the same timer twice? > > > >The timer will only be created if __idletimer_tg_find_by_label() returns > >NULL, which means that no timer with that label has been found. "info" > >won't be the same if info->label is different, right? Or can it change > >on the fly? > > One thing to be generally aware about is that things could potentially > be instantiated by another entity between the time a label was looked up > with negative result and the time one tries to add it. > It may thus be required to extend keeping the lock until after > idletimer_tg_create, in other words, lookup and create must be atomic > to the rest of the world. Ahh, sure! I missed the actual point of Patrick's question. I had the idletimer_tg_create() inside the lock, but when I added the sysfs_create_file() there (which can sleep), I screwed up with the locking. I'll move the sysfs file creation to outside that function so I can keep the lock until after the timer is added to the list. Thanks for clarifying! -- Cheers, Luca. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html