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 38C38EF06E3 for ; Sun, 8 Feb 2026 18:07:45 +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:References: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:List-Owner; bh=yMcDMMO5pUL3iromxDqvHXOfyfcuNP17tBgk7jNq3a8=; b=46MacSR4SxUV2+wEO4/DPh86Me GAgfsflRp3Ok0sfGjfqMjTP0eDLyXszLe5NNFAd18+lAIfTFQg+oHCbpFCq9323AYiajyNdub+dZP ZkNkvESnqx4ClygOUZ7gDLS+jnOZSGEDUr4T/r7TsHimvqYjj0TKuXOAWBUx0DZQJLxPUB1xnbu12 +eiBuvjlIORVpf39gum7Ca7UtDURtX+l5gkqqI3xiNMhV5ZSBDPfse5JxQHLrIvq18j3/W/bTcWfe WE8egJYApDqnDFpro5zZ0ouHES9r8vRkKg1G2EeR/qeHyWWa+4u+QHOGGVir90egIsba9fZ+Mal4B r+cdCRiQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vp9C6-0000000DXPz-36qU; Sun, 08 Feb 2026 18:07:38 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vp9C2-0000000DXPq-1NLc for kexec@lists.infradead.org; Sun, 08 Feb 2026 18:07:34 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 49CD4600BB; Sun, 8 Feb 2026 18:07:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 158FAC4CEF7; Sun, 8 Feb 2026 18:07:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770574053; bh=PxcXwLUBRw69pj0y/iw2r5Y8so1kEeFr6i4iz7h+PcY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eIjSMF/3JMss8Yv+gzQCRJWnr30dkiCVPZJUb/Twq/rYj3Ce0b2P3ZsnTT+JbZyka vlOgGbPj+Hs+7evu4WQ5ZZjNMTbLg8eophnbVM8l5Yw9ZGiNNRYPAhr1wZw7Mnbbjp s2KPl5J79HQ1SNpCBVRfzZ5+IMwcNfGdFOgsV3UiLeNGfPu/PNNdp4cUxruGUrFEv4 wvtSKOjCooDTcqBbHi/diKNhFZrcnm2EgIxJKYeJivAggYo04X0Rr5a4R6B9kAT3/m 7midGG2ywBRApW/wuU82yzTseJINdxFPeWtLzn+sGRIQ3Xm9/dKr0cw8XkzCYvxSLP yE1Cl6ejYcP8g== Date: Sun, 8 Feb 2026 20:07:25 +0200 From: Mike Rapoport To: Jason Miu Cc: Alexander Graf , Andrew Morton , Baoquan He , Changyuan Lyu , David Matlack , David Rientjes , Jason Gunthorpe , Pasha Tatashin , Pratyush Yadav , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v9 1/2] kho: Adopt radix tree for preserved memory tracking Message-ID: References: <20260206021428.3386442-1-jasonmiu@google.com> <20260206021428.3386442-2-jasonmiu@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260206021428.3386442-2-jasonmiu@google.com> X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Thu, Feb 05, 2026 at 06:14:27PM -0800, Jason Miu wrote: > Introduce a radix tree implementation for tracking preserved memory > pages and switch the KHO memory tracking mechanism to use it. This > lays the groundwork for a stateless KHO implementation that eliminates > the need for serialization and the associated "finalize" state. > > This patch introduces the core radix tree data structures and > constants to the KHO ABI. It adds the radix tree node and leaf > structures, along with documentation for the radix tree key encoding > scheme that combines a page's physical address and order. > > To support broader use by other kernel subsystems, such as hugetlb > preservation, the core radix tree manipulation functions are exported > as a public API. > > The xarray-based memory tracking is replaced with this new radix tree > implementation. The core KHO preservation and unpreservation functions > are wired up to use the radix tree helpers. On boot, the second kernel > restores the preserved memory map by walking the radix tree whose root > physical address is passed via the FDT. > > The ABI `compatible` version is bumped to "kho-v2" to reflect the > structural changes in the preserved memory map and sub-FDT property > names. This includes renaming "fdt" to "preserved-data" to better > reflect that preserved state may use formats other than FDT. > > Signed-off-by: Jason Miu Reviewed-by: Mike Rapoport (Microsoft) -- Sincerely yours, Mike.