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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B79DC4332F for ; Thu, 24 Mar 2022 07:27:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 139968D0006; Thu, 24 Mar 2022 03:27:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E9F68D0003; Thu, 24 Mar 2022 03:27:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F1B368D0006; Thu, 24 Mar 2022 03:27:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id E49188D0003 for ; Thu, 24 Mar 2022 03:27:16 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 7D171A4DA2 for ; Thu, 24 Mar 2022 07:27:16 +0000 (UTC) X-FDA: 79278448872.27.065B868 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by imf04.hostedemail.com (Postfix) with ESMTP id 0F5D44002E for ; Thu, 24 Mar 2022 07:27:14 +0000 (UTC) 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 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 9xt9qtpq76cqmtt6jf9nqt47hksrzk4b Authentication-Results: imf04.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf04.hostedemail.com: domain of xiaoguang.wang@linux.alibaba.com designates 115.124.30.132 as permitted sender) smtp.mailfrom=xiaoguang.wang@linux.alibaba.com X-Rspamd-Queue-Id: 0F5D44002E X-HE-Tag: 1648106834-476896 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000533, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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