Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754031Ab0G1Giz (ORCPT ); Wed, 28 Jul 2010 02:38:55 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46172 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752579Ab0G1Giw (ORCPT ); Wed, 28 Jul 2010 02:38:52 -0400 Message-ID: <4C4FD04B.5090503@zytor.com> Date: Tue, 27 Jul 2010 23:38:03 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.7) Gecko/20100720 Fedora/3.1.1-1.fc13 Thunderbird/3.1.1 MIME-Version: 1.0 To: Yinghai Lu CC: Benjamin Herrenschmidt , Ingo Molnar , Thomas Gleixner , Andrew Morton , David Miller , Linus Torvalds , Johannes Weiner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 31/31] memblock: Add memblock_find_in_range() References: <1279822864-17154-1-git-send-email-yinghai@kernel.org> <1279822864-17154-32-git-send-email-yinghai@kernel.org> <1280295415.1970.245.camel@pasglop> <4C4FC95F.6040806@kernel.org> In-Reply-To: <4C4FC95F.6040806@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1269 Lines: 30 On 07/27/2010 11:08 PM, Yinghai Lu wrote: > > for example: > high/low allocation, from first kernel to kexec second kernel, always work fine except system with Qlogic card. > because Qlogic card is using main RAM as EFT etc for card's FW log trace. second kernel have not idea that those RAM > is used by first kernel for that purpose. that the CARD still use that between two kernels. > second kernel could have crash it try to use those ram. > Uhm, no. That's a bug in the Qlogic driver not shutting the card down cleanly. Hacking around that in memory allocation order is braindamaged in the extreme. kexec *cannot* be safe in any way if we don't shut down pending DMA, and what you describe above is DMA. > low/high allocation seems to be safe, second kernel can slip to boot fine. Low to high is just broken. Low memory is a special, desirable resource, and we should minimize the use of it. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/