On 2019/7/17 19:15, Vasily Averin wrote: > On 7/16/19 5:07 PM, Xiaoming Ni wrote: >> On 2019/7/16 18:20, Vasily Averin wrote: >>> On 7/16/19 5:00 AM, Xiaoming Ni wrote: >>>> On 2019/7/15 13:38, Vasily Averin wrote: >>>>> On 7/14/19 5:45 AM, Xiaoming Ni wrote: >>>>>> On 2019/7/12 22:07, gregkh@xxxxxxxxxxxxxxxxxxx wrote: >>>>>>> On Fri, Jul 12, 2019 at 09:11:57PM +0800, Xiaoming Ni wrote: >>>>>>>> On 2019/7/11 21:57, Vasily Averin wrote: >>>>>>>>> On 7/11/19 4:55 AM, Nixiaoming wrote: >>>>>>>>>> On Wed, July 10, 2019 1:49 PM Vasily Averin wrote: >>>>>>>>>>> On 7/10/19 6:09 AM, Xiaoming Ni wrote: .... ... >>>>>>>> So in these two cases, is it more reasonable to trigger BUG() directly when checking for duplicate registration ? >>>>>>>> But why does current notifier_chain_register() just trigger WARN() without exiting ? >>>>>>>> notifier_chain_cond_register() direct exit without triggering WARN() ? >>>>>>> >>>>>>> It should recover from this, if it can be detected. The main point is >>>>>>> that not all apis have to be this "robust" when used within the kernel >>>>>>> as we do allow for the callers to know what they are doing :) >>>>>>> >>>>>> In the notifier_chain_register(), the condition ( (*nl) == n) is the same registration of the same hook. >>>>>> We can intercept this situation and avoid forming a linked list ring to make the API more rob ... ... > Yes, I'm agree, at present there are no difference between > notifier_chain_cond_register() and notifier_chain_register() > > Question is -- how to improve it. > You propose to remove notifier_chain_cond_register() by some way. > Another option is return an error, for some abstract callers who expect possible double registration. > > Frankly speaking I prefer second one, > however because of kernel do not have any such callers right now seems you are right, > and we can delete notifier_chain_cond_register(). > > So let me finally accept your patch-set. > > Thank you, > Vasily Averin > > . > Dear Greg Kroah-Hartman is there any other opinion on this patch set? can you pick this series? thanks Xiaoming Ni
