From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbcL3M5Z (ORCPT ); Fri, 30 Dec 2016 07:57:25 -0500 Received: from mx2.suse.de ([195.135.220.15]:52612 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753848AbcL3M4V (ORCPT ); Fri, 30 Dec 2016 07:56:21 -0500 Date: Fri, 30 Dec 2016 13:56:16 +0100 From: Michal Hocko To: Mel Gorman Cc: David Rientjes , Andrew Morton , Jonathan Corbet , "Kirill A. Shutemov" , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch] mm, thp: always direct reclaim for MADV_HUGEPAGE even when deferred Message-ID: <20161230125615.GH13301@dhcp22.suse.cz> References: <20161222100009.GA6055@dhcp22.suse.cz> <20161230123620.jcuquzof3bpxomdn@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161230123620.jcuquzof3bpxomdn@techsingularity.net> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 30-12-16 12:36:20, Mel Gorman wrote: [...] > I'll neither ack nor nak this patch. However, I would much prefer an > additional option be added to sysfs called defer-fault that would avoid > all fault-based stalls but still potentially stall for MADV_HUGEPAGE. Would you consider changing the semantic of defer=madvise to invoke KSWAPD for !madvised vmas as acceptable. It would be a change in semantic but I am wondering what would be a risk and potential regression space. Also I am planning to send a pro-active compaction based on a "watermark" as an LSF/MM topic proposal. I suspect that no additional thp specific tunable will be needed if we have a proper compaction watermark tunable. -- Michal Hocko SUSE Labs