Changli Gao wrote: > On Thu, Apr 15, 2010 at 6:36 PM, Patrick McHardy <kaber@xxxxxxxxx> wrote: >> Changli Gao wrote: >>> On Tue, Apr 13, 2010 at 9:25 PM, Patrick McHardy <kaber@xxxxxxxxx> wrote: >>>>> Yes, that is why vmalloc() is perfect for this case. No extra memory for >>>>> management, but one pointer for each page of memory. >>>> I agree, if it works for conntrack, it certainly also works for >>>> nfnetlink_queue. >>>> >>> I need to allocate memory in atomic section, so vmalloc() can't be used. :( >> Why? >> > > instance_create() is called in rcu read-side critical section, and the > whole body of this function is protected by the spinlock > instances_lock. All these make memory allocation for queue instances > should be atomic. That should be easily fixable. For the lookup we can add a reference counter so we don't need the rcu read side critical section. For creation the lock actually looks unnecessary since all nfnetlink handlers run under nfnl_mutex, so we can't have concurrent creation and removal of queuing instances. Well, we need it for list insertion to avoid races with the seq file handlers, but we don't need it before that. -- 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
