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 320ABC48BC2 for ; Wed, 23 Jun 2021 11:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2111061076 for ; Wed, 23 Jun 2021 11:16:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230185AbhFWLSc (ORCPT ); Wed, 23 Jun 2021 07:18:32 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:60600 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230031AbhFWLSc (ORCPT ); Wed, 23 Jun 2021 07:18:32 -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 251901FD68; Wed, 23 Jun 2021 11:16:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624446974; 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=KV1EpNdhx/wUSqoUCCroMUV3rsSV7q8YaeMu9XhFW1w=; b=NZQtUKZmTmrFVEGwfUXSMY9FqUsRi1Jw3xX+9BPq7IJbzySyg0LB+IzRSZ3sXK5JcRvoDl kyQehl/IoaXmmx4ocGOYwK3wTBK4xOFOJdyCe9djg4eBMTEDNZH94XYGPW/VZ90G4PN+Oc wIImZT1xG5JLuJr9G0yh0KPuOZcdw/M= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624446974; 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=KV1EpNdhx/wUSqoUCCroMUV3rsSV7q8YaeMu9XhFW1w=; b=sB5qu1IwbpJhmVRmCUOgbBcUdGkf947ZNqvNFQSWqv3Wl7DLck0vjqV/2wmk3bU+DCOrop x5CeeHwJfLYx46Bg== Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id 8E4D711A97; Wed, 23 Jun 2021 11:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1624446974; 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=KV1EpNdhx/wUSqoUCCroMUV3rsSV7q8YaeMu9XhFW1w=; b=NZQtUKZmTmrFVEGwfUXSMY9FqUsRi1Jw3xX+9BPq7IJbzySyg0LB+IzRSZ3sXK5JcRvoDl kyQehl/IoaXmmx4ocGOYwK3wTBK4xOFOJdyCe9djg4eBMTEDNZH94XYGPW/VZ90G4PN+Oc wIImZT1xG5JLuJr9G0yh0KPuOZcdw/M= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1624446974; 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=KV1EpNdhx/wUSqoUCCroMUV3rsSV7q8YaeMu9XhFW1w=; b=sB5qu1IwbpJhmVRmCUOgbBcUdGkf947ZNqvNFQSWqv3Wl7DLck0vjqV/2wmk3bU+DCOrop x5CeeHwJfLYx46Bg== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id UhdYFvsX02DccwAALh3uQQ (envelope-from ); Wed, 23 Jun 2021 11:16:11 +0000 Subject: Re: Ask help for code review (was Re: [PATCH 03/14] bcache: add initial data structures for nvm pages) From: Coly Li 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> Message-ID: <5702503a-56da-b981-90c6-ebd181716901@suse.de> Date: Wed, 23 Jun 2021 19:16:09 +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: <466c1678-8cdc-7240-1422-b435a599cad3@suse.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 6/23/21 6:05 PM, Coly Li wrote: > On 6/23/21 3:21 PM, Christoph Hellwig wrote: > Does the already mapped DAX base address change in runtime during memory > hot plugable ? > 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 ? > Hi Christoph, I feel I come to understand "It could change between one use and another." Yes, this is a problem for full pointer design. I will switch to base + offset format. Thank you for joining the discussion and provide your comments, to help me have improved understand for better design :-） Coly Li