On Thu, Apr 18, 2013 at 02:52:31AM +0800, Xiao Guangrong wrote: > On 04/18/2013 02:45 AM, Robin Holt wrote: > > >>>>>>> For the v3.10 release, we should work on making this more > >>>>>>> correct and completely documented. > >>>>>> > >>>>>> Better document is always welcomed. > >>>>>> > >>>>>> Double call ->release is not bad, like i mentioned it in the changelog: > >>>>>> > >>>>>> it is really rare (e.g, can not happen on kvm since mmu-notify is unregistered > >>>>>> after exit_mmap()) and the later call of multiple ->release should be > >>>>>> fast since all the pages have already been released by the first call. > >>>>>> > >>>>>> But, of course, it's great if you have a _light_ way to avoid this. > >>>>> > >>>>> Getting my test environment set back up took longer than I would have liked. > >>>>> > >>>>> Your patch passed. I got no NULL-pointer derefs. > >>>> > >>>> Thanks for your test again. > >>>> > >>>>> > >>>>> How would you feel about adding the following to your patch? > >>>> > >>>> I prefer to make these changes as a separate patch, this change is the > >>>> improvement, please do not mix it with bugfix. > >>> > >>> I think your "improvement" classification is a bit deceiving. My previous > >>> patch fixed the bug in calling release multiple times. Your patch without > >>> this will reintroduce that buggy behavior. Just because the bug is already > >>> worked around by KVM does not mean it is not a bug. > >> > >> As your tested, calling ->release() multiple times can work, but just make your > >> testcase more _slower_. So your changes is trying to speed it up - it is a > >> improvement. > >> > >> Well, _if_ it is really a bug, could you please do not fix two bugs in one patch? > > > > The code, as is, does not call ->release() multiple times. Your code > > changes the behavior to call it multiple times. You are introducing the > > bug by your code changes. Why not fix the bug you create in the patch > > which creates it? > > Andrew, your thought? > What ever happened with this? Robin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
