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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 48504C43458 for ; Wed, 8 Jul 2026 11:14:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=ddJSAPVz9NkXc1bzGsPcnDtadMHor6sj1Pq8riASaWE=; b=gmxXk+4O7xlqCv MULPpupm2sZQeqHK3GK8foFDAxLUJE4WT7DHcfuMMUTv4mrv5MF4wvLd80oskwRaqMmEXjoH12QT8 BoyneV0eCr0OnNvmVFyEiFx8K3j3hdavf2+CuHUB4Hae+kBPa52gXsdFs6OpGbW6ao7EBL82WmQaK juyIINuLaIUfr2UASvgALmpQolJBQNjWRVcdTzlzC7+5AiZK7hbeVRketNRwhdwWQJYJPG3ZPvY2O iE916EAyvTPShUTj2BFdzZgBXqYWKdL+KNnrLkMYYH4nlg61jawWzbl8wLAccLf6z8uLb1iYllPxQ NKWG++1bn0d9Sag5v0EQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whP54-0000000Gndn-1G8Q; Wed, 08 Jul 2026 10:00:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whP50-0000000Gnd3-2s3r for linux-arm-kernel@lists.infradead.org; Wed, 08 Jul 2026 10:00:36 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B75871E5E; Wed, 8 Jul 2026 03:00:28 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 31A4B3F85F; Wed, 8 Jul 2026 03:00:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783504833; bh=8oFU73UDNb1/JzzX/59Hz8/SUvhrGo6jInm1l2EOvkk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=K2QzZNWS5qvtc90qr2P/bmEBxGozBIkajd4g2BYgXL6Gp07XfQg2fDAaRimBjytR3 AnMyVUC1k+1MwDKxSrlcekXCA+Xo6jxwuhPGUKvb9LNjSYAl8jWKoOD6L8rj1fhHUR MBLQpicTg0GtL6aQ3jsYy8mAbKKMKwErUf1HScIM= Date: Wed, 8 Jul 2026 11:00:27 +0100 From: Catalin Marinas To: Shyam Saini Cc: Mike Rapoport , ardb@kernel.org, david@kernel.org, will@kernel.org, linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org, bboscaccy@linux.microsoft.com, bp@alien8.de, dapeng1.mi@linux.intel.com, ebiggers@kernel.org, elver@google.com, enelsonmoore@gmail.com, feng.tang@linux.alibaba.com, gpiccoli@igalia.com, kees@kernel.org, kuba@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lirongqing@baidu.com, peterz@infradead.org, rdunlap@infradead.org, tgopinath@linux.microsoft.com, tony.luck@intel.com, Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla Subject: Re: [RFC v2 PATCH] reserve_mem: add support for static memory Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260630170911.43521-1-shyamsaini@linux.microsoft.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260708_030034_849474_7DB60DF2 X-CRM114-Status: UNSURE ( 9.52 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Shyam, Adding Lorenzo, Hanjun, Sudeep. On Tue, Jun 30, 2026 at 10:09:11AM -0700, Shyam Saini wrote: > Following up on this, As Mike pointed that reserve_mem is best effort > reservation mechanism, so what is the recommended reliable Linux > mechanism, if any, to reserve a predetermined memory range during > early boot on ARM64/ACPI platforms for warm boot scenarios? KHO is > one option, but I'm specifically looking for a solution that preserves > the region across warm reboots. If you need ramoops-like support, I think ACPI ERST is a better fit and we don't need any memory reservation tricks. I'll let the arm ACPI maintainers comment further. -- Catalin