From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 173C0606A31D for ; Wed, 21 Oct 2026 13:23:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=23L4rNZH; dkim=fail reason="signature verification failed" (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Mt3hXrxe DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Wed, 21 Oct 2026 13:23:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792588990; bh=pAAU30bwGvhgKc2fcWmaPUnM+q1nxRImGaxZJ4BonqU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Mt3hXrxeKJoJfLibADZIcsXR7rI+NO9d5jFB7CsWQi7wKkA7Ivi+NuujoLsu6N0Sj xeAk+R1NrRVYx1sYEncPNYK1tOB4gOmoV/soXvOeMmPj9evSIL4UZE8ME5ru4NQo5h rdmao/ez90tKUwo3/XUgCH2iLLiz95UkX5/e2YrP1miGaCfo8O/R8cfIYLVig3VVnr r1iNDVPFLS7bpM7kU7EAqqH+8hkxOiLRbqqi3tb+hZaOnZwWSQEHk7khqjrR4q7t3A S0lU2etMBYUN25UboD24fjrlEjMmDt+fIwEsaB4T+GmpTzCmxcQVMevggk/I2FaJ6K 4dRr3m+UTBq7A== Date: Wed, 21 Oct 2026 08:23:08 -0500 From: Rob Herring To: Wandun Chen Cc: baoquan.he@linux.dev, rppt@kernel.org, m.szyprowski@samsung.com, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, chenhuacai@kernel.org, kernel@xen0n.name, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, saravanak@kernel.org, akpm@linux-foundation.org, pasha.tatashin@soleen.com, pratyush@kernel.org, ruirui.yang@linux.dev, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, iommu@lists.linux.dev Subject: Re: [PATCH v9 0/8] kdump: reduce vmcore size and capture time Message-ID: <20261021132308.GB3667411-robh@kernel.org> References: <20261021083011.2170525-1-chenwandun1@gmail.com> X-Archived-By: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20261021083011.2170525-1-chenwandun1@gmail.com> X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Oct 21, 2026 at 04:30:03PM +0800, Wandun Chen wrote: > From: Wandun Chen > > On SoCs that carve out large firmware-owned reserved memory (GPU, > camera ISP, ...), kdump currently dumps those carveouts as part of > system RAM even though their contents are firmware state that is not > useful for kernel crash analysis. > > ACPI systems already filter reserved memory out of the vmcore through > their existing path: firmware reports those carveouts as unusable in > the EFI memory map, they get MEMBLOCK_NOMAP set in memblock.memory > (is_usable_memory(), efi-init.c), and the ELF header builder has > always skipped nomap regions; only DT-based systems currently fail > to filter these regions, which is what this series addresses. > > This series introduces a MEMBLOCK_NODUMP flag (suggested by Rob) in > memblock to filter reserved memory on DT-based architectures. A new > flag is needed because MEMBLOCK_NOMAP can only express regions without > a linear mapping, while MEMBLOCK_NODUMP can filter regions that are > linearly mapped. Reserved regions are marked MEMBLOCK_NODUMP by default > so kdump omits them; reusable CMA regions are different because their > pages are handed back to the buddy allocator and may carry crash-relevant > data. There is little point in continuing to send new versions until Mike agrees with MEMBLOCK_NODUMP being added. You didn't answer him on v7. Also, I intend to apply this[1] before any further reserved memory changes which will greatly simplify the code. Rob [1] https://lore.kernel.org/all/20261015082315.56876-1-m.szyprowski@samsung.com/ _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv