From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH] mm: mmu_notifier: re-fix freed page still mapped in secondary MMU Date: Wed, 17 Apr 2013 10:55:26 +0800 Message-ID: <516E0F1E.5090805@linux.vnet.ibm.com> References: <516CF235.4060103@linux.vnet.ibm.com> <20130416093131.GJ3658@sgi.com> <516D275C.8040406@linux.vnet.ibm.com> <20130416112553.GM3658@sgi.com> <20130416114322.GN3658@sgi.com> <516D4D08.9020602@linux.vnet.ibm.com> <20130416180835.GY3658@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Andrew Morton , Marcelo Tosatti , Gleb Natapov , Avi Kivity , Andrea Arcangeli , LKML , KVM , Linux Memory Management List To: Robin Holt Return-path: In-Reply-To: <20130416180835.GY3658@sgi.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org On 04/17/2013 02:08 AM, Robin Holt wrote: > On Tue, Apr 16, 2013 at 09:07:20PM +0800, Xiao Guangrong wrote: >> On 04/16/2013 07:43 PM, Robin Holt wrote: >>> Argh. Taking a step back helped clear my head. >>> >>> For the -stable releases, I agree we should just go with your >>> revert-plus-hlist_del_init_rcu patch. I will give it a test >>> when I am in the office. >> >> Okay. Wait for your test report. Thank you in advance. >> >>> >>> 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. You can make a patchset (comments improvement and this change) based on my fix. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org