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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 DB451C4743C for ; Wed, 23 Jun 2021 12:09:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA26460FE5 for ; Wed, 23 Jun 2021 12:09:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230189AbhFWMMA (ORCPT ); Wed, 23 Jun 2021 08:12:00 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:39010 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230157AbhFWML7 (ORCPT ); Wed, 23 Jun 2021 08:11:59 -0400 Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id BBC201FD36; Wed, 23 Jun 2021 12:09:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624450181; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Shj2SE8niP5WvMXjun7ikIAkYYmoq/GAPEpKa0VAbKw=; b=V6zOpxwZ3ibpNomE4ANU88oKCgVPTKMgpkOrt/3kF2XYMasevOWE4rl/jqrfrqOem+tNlM pIOD97FZ04RURUyFojM60Ljqmt2xhcSNDYYy5ItAHtZwI9VsWOXIsMuWNibiCR/yxW6E4o 1F4vSu5sUbVf8bBQK9KYlMqzqbarT18= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624450181; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Shj2SE8niP5WvMXjun7ikIAkYYmoq/GAPEpKa0VAbKw=; b=IFkPNpq/JVrj//USk0ZjtbAYNn/8J5Hfx9xjSwCeWfFtbI9AZf34t+cKRqFZLiqfsJDQcZ iV8e1SKZ8bJ9aYAw== Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id 9633911A97; Wed, 23 Jun 2021 12:09:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624450181; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Shj2SE8niP5WvMXjun7ikIAkYYmoq/GAPEpKa0VAbKw=; b=V6zOpxwZ3ibpNomE4ANU88oKCgVPTKMgpkOrt/3kF2XYMasevOWE4rl/jqrfrqOem+tNlM pIOD97FZ04RURUyFojM60Ljqmt2xhcSNDYYy5ItAHtZwI9VsWOXIsMuWNibiCR/yxW6E4o 1F4vSu5sUbVf8bBQK9KYlMqzqbarT18= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624450181; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Shj2SE8niP5WvMXjun7ikIAkYYmoq/GAPEpKa0VAbKw=; b=IFkPNpq/JVrj//USk0ZjtbAYNn/8J5Hfx9xjSwCeWfFtbI9AZf34t+cKRqFZLiqfsJDQcZ iV8e1SKZ8bJ9aYAw== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id IgYZGYMk02AEEwAALh3uQQ (envelope-from ); Wed, 23 Jun 2021 12:09:39 +0000 Subject: Re: Ask help for code review (was Re: [PATCH 03/14] bcache: add initial data structures for nvm pages) To: Christoph Hellwig Cc: "Huang, Ying" , Dan Williams , Jan Kara , Hannes Reinecke , linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, Jianpeng Ma , Qiaowei Ren , axboe@kernel.dk References: <20210615054921.101421-1-colyli@suse.de> <20210615054921.101421-4-colyli@suse.de> <24ad3795-813c-b50b-e983-56dccef1b0db@suse.de> <875yy6l2a1.fsf@yhuang6-desk2.ccr.corp.intel.com> <87czsdhy0u.fsf@yhuang6-desk2.ccr.corp.intel.com> <20210623070405.GA537@lst.de> <20210623072140.GA837@lst.de> <466c1678-8cdc-7240-1422-b435a599cad3@suse.de> <20210623114954.GA20363@lst.de> From: Coly Li Message-ID: <3d84ecc3-4ebf-3ef4-e4e3-df39e661f854@suse.de> Date: Wed, 23 Jun 2021 20:09:37 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210623114954.GA20363@lst.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org On 6/23/21 7:49 PM, Christoph Hellwig wrote: > On Wed, Jun 23, 2021 at 06:05:51PM +0800, Coly Li wrote: >> The cache device (typically SSD) of bcache is designed to dedicate to a >> single local machine. Any >> storage migration between machines with different endians should firstly >> flush the dirty data to >> backing hard drive. > Now my G5 died and I need to recover the data using my x86 laptop, > what am I going to do? > >>>> If not, it won't be a problem here for this specific use case. >>> It could change between one use and another. >> Hmm, I don't understand the implicit meaning of the above line. >> Could you please offer a detail example ? > There is no guarantee you nvdimm or CXL memory device will show up > at the same address. Copied, I fully understand. Now I am working on the full pointer to [base + offset] convert. Thanks for your patient explanation :-) Coly Li