From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f182.google.com (mail-wi0-f182.google.com [209.85.212.182]) by kanga.kvack.org (Postfix) with ESMTP id 0CBDF6B0036 for ; Fri, 10 Jan 2014 17:52:10 -0500 (EST) Received: by mail-wi0-f182.google.com with SMTP id en1so217307wid.3 for ; Fri, 10 Jan 2014 14:52:10 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id ib3si4522148wjb.48.2014.01.10.14.52.09 for ; Fri, 10 Jan 2014 14:52:09 -0800 (PST) Message-ID: <52D07966.4000205@redhat.com> Date: Fri, 10 Jan 2014 17:51:18 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [patch 7/9] mm: thrash detection-based file cache sizing References: <1389377443-11755-1-git-send-email-hannes@cmpxchg.org> <1389377443-11755-8-git-send-email-hannes@cmpxchg.org> In-Reply-To: <1389377443-11755-8-git-send-email-hannes@cmpxchg.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Andrew Morton Cc: Andi Kleen , Andrea Arcangeli , Bob Liu , Christoph Hellwig , Dave Chinner , Greg Thelen , Hugh Dickins , Jan Kara , KOSAKI Motohiro , Luigi Semenzato , Mel Gorman , Metin Doslu , Michel Lespinasse , Minchan Kim , Ozgun Erdogan , Peter Zijlstra , Roman Gushchin , Ryan Mallon , Tejun Heo , Vlastimil Babka , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org On 01/10/2014 01:10 PM, Johannes Weiner wrote: > This patch solves one half of the problem by decoupling the ability to > detect working set changes from the inactive list size. By > maintaining a history of recently evicted file pages it can detect > frequently used pages with an arbitrarily small inactive list size, > and subsequently apply pressure on the active list based on actual > demand for cache, not just overall eviction speed. > > Every zone maintains a counter that tracks inactive list aging speed. > When a page is evicted, a snapshot of this counter is stored in the > now-empty page cache radix tree slot. On refault, the minimum access > distance of the page can be assessed, to evaluate whether the page > should be part of the active list or not. > > This fixes the VM's blindness towards working set changes in excess of > the inactive list. And it's the foundation to further improve the > protection ability and reduce the minimum inactive list size of 50%. > > Signed-off-by: Johannes Weiner Reviewed-by: Rik van Riel -- All rights reversed -- 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