On Wednesday 2010-06-09 17:11, Luciano Coelho wrote: >> >> How does this work with multiple namespaces? It seems every namespace >> can bind to any timer. > >I was implementing this solution for multiple namespaces (see the >previous versions of my patch), but the code started getting really >complicated. Then I found out that sysfs and multiple namespaces are >not working very well together yet and decided to drop it for the time >being. Of course this doesn't matter anymore, since the timers belong >to an independent class in sysfs, so I can easily add multiple namespace >support by adding struct net *net as part of the list key together with >the label. > >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. :) >> > + 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. -- 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