From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6123-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 14488985C72 for ; Wed, 11 Sep 2019 16:09:31 +0000 (UTC) References: <20190910175213.GD4023@dhcp22.suse.cz> <1d7de9f9f4074f67c567dbb4cc1497503d739e30.camel@linux.intel.com> <20190911113619.GP4023@dhcp22.suse.cz> <20190911080804-mutt-send-email-mst@kernel.org> <20190911121941.GU4023@dhcp22.suse.cz> <20190911122526.GV4023@dhcp22.suse.cz> <4748a572-57b3-31da-0dde-30138e550c3a@redhat.com> <20190911125413.GY4023@dhcp22.suse.cz> <736594d6-b9ae-ddb9-2b96-85648728ef33@redhat.com> <20190911132002.GA4023@dhcp22.suse.cz> <20190911135100.GC4023@dhcp22.suse.cz> From: David Hildenbrand Message-ID: Date: Wed, 11 Sep 2019 18:09:18 +0200 MIME-Version: 1.0 In-Reply-To: <20190911135100.GC4023@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: [virtio-dev] Re: [PATCH v9 0/8] stg mail -e --version=v9 \ To: Michal Hocko Cc: "Michael S. Tsirkin" , Alexander Duyck , Alexander Duyck , virtio-dev@lists.oasis-open.org, kvm list , Catalin Marinas , Dave Hansen , LKML , Matthew Wilcox , linux-mm , Andrew Morton , will@kernel.org, linux-arm-kernel@lists.infradead.org, Oscar Salvador , Yang Zhang , Pankaj Gupta , Konrad Rzeszutek Wilk , Nitesh Narayan Lal , Rik van Riel , lcapitulino@redhat.com, "Wang, Wei W" , Andrea Arcangeli , ying.huang@intel.com, Paolo Bonzini , Dan Williams , Fengguang Wu , "Kirill A. Shutemov" List-ID: On 11.09.19 15:51, Michal Hocko wrote: > On Wed 11-09-19 15:20:02, Michal Hocko wrote: > [...] >>> 4. Continuously report, not the "one time report everything" approach. >> >> So you mean the allocator reporting this rather than an external code to >> poll right? I do not know, how much this is nice to have than must have? > > Another idea that I haven't really thought through so it might turned > out to be completely bogus but let's try anyway. Your "report everything" > just made me look and realize that free_pages_prepare already performs > stuff that actually does something similar yet unrelated. > > We do report to special page poisoning, zeroying or > CONFIG_DEBUG_PAGEALLOC to unmap the address from the kernel address > space. This sounds like something fitting your model no? > AFAIKS, the poisoning/unmapping is done whenever a page is freed. I don't quite see yet how that would help to remember if a page was already reported. After reporting the page we would have to switch some state (Nitesh: bitmap bit, Alexander: page flag) to identify that. Of course, we could map the page and treat that as "the state" when we reported it, but I am not sure that's such a good idea :) As always, I might be very wrong ... -- Thanks, David / dhildenb --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org