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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0725DC433F5 for ; Thu, 24 Mar 2022 07:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348537AbiCXH2p (ORCPT ); Thu, 24 Mar 2022 03:28:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232088AbiCXH2o (ORCPT ); Thu, 24 Mar 2022 03:28:44 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6986998F63; Thu, 24 Mar 2022 00:27:12 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0V83t.bs_1648106829; Received: from 30.225.28.175(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0V83t.bs_1648106829) by smtp.aliyun-inc.com(127.0.0.1); Thu, 24 Mar 2022 15:27:10 +0800 Message-ID: Date: Thu, 24 Mar 2022 15:27:08 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [RFC 1/3] mm/memory.c: introduce vm_insert_page(s)_mkspecial Content-Language: en-US To: Christoph Hellwig Cc: linux-mm@kvack.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, xuyu@linux.alibaba.com, bostroesser@gmail.com References: <20220318095531.15479-1-xiaoguang.wang@linux.alibaba.com> <20220318095531.15479-2-xiaoguang.wang@linux.alibaba.com> From: Xiaoguang Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org hi, > I relaly don't think we should add this amount of overhead to the > core VM for a (relatively) irrelevant driver. OK, but as what I have described in cover letter, both vm_insert_pages and remap_pfn_range have performance or usage limits. Do you know any better method to map block device io request's sgl pages to user space? I think block device backend implemented in use space will benefit from this feature, thanks. Regards, Xiaoguang Wang