From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753179AbdHNLuF (ORCPT ); Mon, 14 Aug 2017 07:50:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:56502 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752843AbdHNLuE (ORCPT ); Mon, 14 Aug 2017 07:50:04 -0400 Date: Mon, 14 Aug 2017 13:50:01 +0200 From: Michal Hocko To: Pasha Tatashin Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org Subject: Re: [v6 15/15] mm: debug for raw alloctor Message-ID: <20170814115000.GJ19063@dhcp22.suse.cz> References: <1502138329-123460-1-git-send-email-pasha.tatashin@oracle.com> <1502138329-123460-16-git-send-email-pasha.tatashin@oracle.com> <20170811130831.GN30811@dhcp22.suse.cz> <87d84cad-f03a-88f0-7828-6d3bf7ac473c@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87d84cad-f03a-88f0-7828-6d3bf7ac473c@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 11-08-17 12:18:24, Pasha Tatashin wrote: > >>When CONFIG_DEBUG_VM is enabled, this patch sets all the memory that is > >>returned by memblock_virt_alloc_try_nid_raw() to ones to ensure that no > >>places excpect zeroed memory. > > > >Please fold this into the patch which introduces > >memblock_virt_alloc_try_nid_raw. > > OK > > I am not sure CONFIG_DEBUG_VM is the > >best config because that tends to be enabled quite often. Maybe > >CONFIG_MEMBLOCK_DEBUG? Or even make it kernel command line parameter? > > > > Initially, I did not want to make it CONFIG_MEMBLOCK_DEBUG because we really > benefit from this debugging code when VM debug is enabled, and especially > struct page debugging asserts which also depend on CONFIG_DEBUG_VM. > > However, now thinking about it, I will change it to CONFIG_MEMBLOCK_DEBUG, > and let users decide what other debugging configs need to be enabled, as > this is also OK. Actually the more I think about it the more I am convinced that a kernel boot parameter would be better because it doesn't need the kernel to be recompiled and it is a single branch in not so hot path. -- Michal Hocko SUSE Labs