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 8CAB66B0285 for ; Wed, 23 May 2018 04:43:47 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id r2-v6so286429wrm.15 for ; Wed, 23 May 2018 01:43:47 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l46-v6si252488edd.291.2018.05.23.01.43.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 23 May 2018 01:43:46 -0700 (PDT) Date: Wed, 23 May 2018 10:43:42 +0200 From: Michal Hocko Subject: Re: [RFC] trace when adding memory to an offline nod Message-ID: <20180523084342.GK20441@dhcp22.suse.cz> References: <20180523080108.GA30350@techadventures.net> <20180523083756.GJ20441@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180523083756.GJ20441@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Oscar Salvador Cc: linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@oracle.com, dan.j.williams@intel.com On Wed 23-05-18 10:37:56, Michal Hocko wrote: > On Wed 23-05-18 10:01:08, Oscar Salvador wrote: > > Hi guys, > > > > while testing memhotplug, I spotted the following trace: > > > > ===== > > linux kernel: WARNING: CPU: 0 PID: 64 at ./include/linux/gfp.h:467 vmemmap_alloc_block+0x4e/0xc9 > > This warning is too loud and not really helpful. We are doing > gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN; > > page = alloc_pages_node(node, gfp_mask, order); > > so we do not really insist on the allocation succeeding on the requested > node (it is more a hint which node is the best one but we can fallback > to any other node). Moreover we do explicitly do not care about > allocation warnings by __GFP_NOWARN. So maybe we want to soften the > warning like this? > The patch with the full changelog