From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F48AC433F5 for ; Thu, 30 Aug 2018 12:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D777F2082C for ; Thu, 30 Aug 2018 12:49:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D777F2082C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728884AbeH3QvR (ORCPT ); Thu, 30 Aug 2018 12:51:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:54064 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728713AbeH3QvR (ORCPT ); Thu, 30 Aug 2018 12:51:17 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 496F0AE88; Thu, 30 Aug 2018 12:49:16 +0000 (UTC) Date: Thu, 30 Aug 2018 14:49:15 +0200 From: Michal Hocko To: Thomas Gleixner Cc: Peter Zijlstra , Feng Tang , linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar , "H . Peter Anvin" , Yinghai Lu , Dave Hansen , Andi Kleen Subject: Re: [PATCH] x86, mm: Reserver some memory for bootmem allocator for NO_BOOTMEM Message-ID: <20180830124915.GH2656@dhcp22.suse.cz> References: <20180830090319.985-1-feng.tang@intel.com> <20180830104401.GZ24124@hirez.programming.kicks-ass.net> <20180830111207.GE2656@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 30-08-18 13:54:19, Thomas Gleixner wrote: > On Thu, 30 Aug 2018, Michal Hocko wrote: > > On Thu 30-08-18 12:44:02, Peter Zijlstra wrote: > > > On Thu, Aug 30, 2018 at 05:03:19PM +0800, Feng Tang wrote: > > > > The root cause is that when CONFIG_NO_BOOTMEM=y, before > > > > e820__memblock_setup() is called there is no memory for bootmem > > > > to allocate, > > > > > > Which you bloody well asked for by using NO_BOOTMEM=y. > > > > > > Going down this route; adding hacks for every little thing that does > > > want bootmem, completely defeats the purpose. > > > > > > If anything, make the earlycon thing depend on NO_BOOTMEM=n. That also > > > solves your problem. No earlycon, no panic. > > > > Well, there is endeavor to remove bootmem allocator altogether. So > > making earlycon depend on NO_BOOTMEM=n doesn't sound like a good fit to > > If we want to remove bootmem, then reintroducing it with a static bootmem > section doesn't make any sense at all. I have actually checked the code now and see what you mean. I thought it would be a single allocation that is needed but that is not the case so the static buffer is not going to fly. -- Michal Hocko SUSE Labs