From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH -mm v9 0/8] idle memory tracking Date: Wed, 29 Jul 2015 18:31:35 +0300 Message-ID: <20150729153135.GW8100@esperanza> References: <20150729123629.GI15801@dhcp22.suse.cz> <20150729135907.GT8100@esperanza> <20150729144539.GU8100@esperanza> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michel Lespinasse Cc: Michal Hocko , Andrew Morton , Andres Lagar-Cavilla , Minchan Kim , Raghavendra K T , Johannes Weiner , Greg Thelen , David Rientjes , Pavel Emelyanov , Cyrill Gorcunov , Jonathan Corbet , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Wed, Jul 29, 2015 at 08:08:22AM -0700, Michel Lespinasse wrote: > On Wed, Jul 29, 2015 at 7:45 AM, Vladimir Davydov > wrote: > > Page table scan approach has the inherent problem - it ignores unmapped > > page cache. If a workload does a lot of read/write or map-access-unmap > > operations, we won't be able to even roughly estimate its wss. > > You can catch that in mark_page_accessed on those paths, though. Actually, the problem here is how to find an unmapped page cache page *to mark it idle*, not to mark it accessed. Thanks, Vladimir