From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 6DF856B0007 for ; Fri, 13 Apr 2018 02:59:49 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id 31so4295576wrr.2 for ; Thu, 12 Apr 2018 23:59:49 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id m12si2629589eda.538.2018.04.12.23.59.47 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 12 Apr 2018 23:59:48 -0700 (PDT) Date: Fri, 13 Apr 2018 08:59:44 +0200 From: Michal Hocko Subject: Re: [PATCH 1/3] mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES Message-ID: <20180413065944.GE17484@dhcp22.suse.cz> References: <20180305133743.12746-1-guro@fb.com> <20180305133743.12746-2-guro@fb.com> <08524819-14ef-81d0-fa90-d7af13c6b9d5@suse.cz> <20180411135624.GA24260@castle.DHCP.thefacebook.com> <46dbe2a5-e65f-8b72-f835-0210bc445e52@suse.cz> <20180412145702.GB30714@castle.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180412145702.GB30714@castle.DHCP.thefacebook.com> Sender: owner-linux-mm@kvack.org List-ID: To: Roman Gushchin Cc: Vlastimil Babka , linux-mm@kvack.org, Andrew Morton , Alexander Viro , Johannes Weiner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Linux API On Thu 12-04-18 15:57:03, Roman Gushchin wrote: > On Thu, Apr 12, 2018 at 08:52:52AM +0200, Vlastimil Babka wrote: [...] > > We would be just making the reported values more precise wrt reality. > > It depends on if we believe that only slab memory can be reclaimable > or not. If yes, this is true, otherwise not. > > My guess is that some drivers (e.g. networking) might have buffers, > which are reclaimable under mempressure, and are allocated using > the page allocator. But I have to look closer... Well, we have many direct page allocator users which are not accounted in vmstat. Some of those use their specific accounting (e.g. network buffers, some fs metadata a many others). In the ideal world MM layer would know about those but... Anyway, this particular case is quite clear, no? We _use_ kmalloc so this is slab allocator. We just misaccount it. -- Michal Hocko SUSE Labs