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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,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 C7C08C282C2 for ; Wed, 13 Feb 2019 11:21:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9699820821 for ; Wed, 13 Feb 2019 11:21:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AaxbWAV4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9699820821 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HMQVpFf1xG3/QQrehaSG/NTvsNDu/k+Afhzdxk3ZKYA=; b=AaxbWAV47aKdji biks+py+ktnPTDe/hrCMu3BJ6Sejx3tBc97llBR+jTQr9Pces9go3/wq+vCi+77L1fYN7YrTaRYN1 N7KVaZv1GbPL28+UUPfivXvmfYrDcyzo4XE7RbPq7B6gKcYQaLGVLqdRWVFoO2q/ZT7oUUkK2B5NZ 7cZwtv/hRFUQlLdBSW2VsNmHATdoTuP23HeXrxCFqKR1YkE3pLL//RRlOrchOm4wD293FOZCabFjy sdBu/d+sp13ICaING9qvlOx4FBHg1rXVqSwuvAW8rtAChXdQx8SKlhfbD+YEYv0PpfVP3313hm0NA h2A8d7uQ5rIuH94g9CDQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtsby-0002oD-UJ; Wed, 13 Feb 2019 11:21:54 +0000 Received: from outbound-smtp11.blacknight.com ([46.22.139.106]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtsbs-0002ef-Lw for linux-arm-kernel@lists.infradead.org; Wed, 13 Feb 2019 11:21:51 +0000 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp11.blacknight.com (Postfix) with ESMTPS id 7F6801C20B8 for ; Wed, 13 Feb 2019 11:21:43 +0000 (GMT) Received: (qmail 5961 invoked from network); 13 Feb 2019 11:21:43 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[37.228.225.79]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 13 Feb 2019 11:21:43 -0000 Date: Wed, 13 Feb 2019 11:21:41 +0000 From: Mel Gorman To: Will Deacon Subject: Re: 5.0-rc kernel hangs on early boot Message-ID: <20190213112141.GO9565@techsingularity.net> References: <20190213082134.GA21834@yury-thinkpad> <20190213111843.GA1912@brain-police> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190213111843.GA1912@brain-police> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190213_032149_257555_18D610E6 X-CRM114-Status: GOOD ( 14.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrea Arcangeli , Yury Norov , Vlastimil Babka , Catalin Marinas , linux-kernel@vger.kernel.org, Michal Hocko , Zi Yan , David Rientjes , Andrew Morton , Linus Torvalds , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Feb 13, 2019 at 11:18:44AM +0000, Will Deacon wrote: > Hi Yury, > > On Wed, Feb 13, 2019 at 11:25:40AM +0300, Yury Norov wrote: > > My kernel on qemu/arm64 setup hangs at early boot since v5.0-rc1. > > Backtrace is not too verbose: > > (gdb) i threads > > Id Target Id Frame > > * 1 Thread 1 (CPU#0 [running]) 0xffff000010a49b74 in __delay (cycles=4096) > > at arch/arm64/lib/delay.c:49 > > 2 Thread 2 (CPU#1 [halted ]) 0x0000000000000000 in ?? () > > 3 Thread 3 (CPU#2 [halted ]) 0x0000000000000000 in ?? () > > 4 Thread 4 (CPU#3 [halted ]) 0x0000000000000000 in ?? () > > (gdb) bt > > #0 0xffff000010a49b74 in __delay (cycles=4096) at arch/arm64/lib/delay.c:49 > > Backtrace stopped: previous frame identical to this frame (corrupt stack?) > > > > Reverting the patch > > 1c30844d2dfe272d58c ("mm: reclaim small amounts of memory when an external > > fragmentation event occurs") together with following patch > > 73444bc4d8f92e46a20 ("mm, page_alloc: do not wake kswapd with zone lock held") > > helps me to boot normally. > > > > Some system information is below, and config is attached. > > FWIW, running with your command-line and .config under KVM with earlycon > leads to an early page allocation failure followed by a NULL dereference > during boot if only 1G is configured (log below). For the mm folks, it's > probably worth pointing out that you're using 64k pages. > Thanks Will. While I agree that going OOM early is a problem and would explain why the boosting logic was hit at all, it's still the case that the boosting should not divide by zero. Even if the booting is broken due to a lack of memory, I'd still not prefer to crash due to 1c30844d2dfe272d58c. -- Mel Gorman SUSE Labs _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel