From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933943AbdLVJHZ (ORCPT ); Fri, 22 Dec 2017 04:07:25 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:2754 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933927AbdLVJHQ (ORCPT ); Fri, 22 Dec 2017 04:07:16 -0500 Subject: Re: [PATCH v2] devres: use MACRO instead of function for devm_ioremap To: Greg KH References: <1511601813-20533-1-git-send-email-xieyisheng1@huawei.com> <20171219084641.GA15010@kroah.com> <1e5a475c-47c4-a848-03ba-3af5d187ff76@huawei.com> <80cbf37c-3a82-b483-cb67-cc64477136d9@huawei.com> <20171221150859.GA13518@kroah.com> CC: , , , , , From: Yisheng Xie Message-ID: <54e2dac4-3f8e-4dad-d71c-09572039bd39@huawei.com> Date: Fri, 22 Dec 2017 17:06:46 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <20171221150859.GA13518@kroah.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.40] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 2017/12/21 23:08, Greg KH wrote: > On Thu, Dec 21, 2017 at 07:50:16PM +0800, Yisheng Xie wrote: >> Hi Greg, >> >> On 2017/12/19 18:52, Yisheng Xie wrote: >>> Hi Greg, >>> >>> On 2017/12/19 16:46, Greg KH wrote: >>>> On Sat, Nov 25, 2017 at 05:23:33PM +0800, Yisheng Xie wrote: >>>>> Default ioremap is ioremap_nocache, so devm_ioremap has the same function >>>>> with devm_ioremap_nocache, which may just be killed. However, there are >>>>> many places which use devm_ioremap_nocache, while many use devm_ioremap. >>>>> >>>>> This patch is to use MACRO for devm_ioremap, which will reduce the size of >>>>> devres.o from 206824 Bytes to 203768 Bytes. >>>> >>>> Ok, the idea is good, but why not just get rid of the callers of >>>> devm_ioremap_nocache() instead and have them call devm_ioremap() if they >>>> really are the same thing? No need to keep a macro around for the >>>> duplicate thing, just delete the one and things are much better. >>> >>> Yeah, I thought someone may still want to use devm_ioremap_nocache(). >>> >>> I will take your suggestion in next version and kill devm_ioremap_nocache(). >> >> I am trying to kill devm_ioremap_nocache() as your suggestion, however, if >> put it as a single patch it will be a patch really big (the patch file may >> have more than 1k lines), for many places will use devm_ioremap_nocache(). >> But it also makes me fell uncomfortable to separate it to so many litter >> patchs for a litter optimize. :) >> >> So I put the v3 patch in the attachment, please let me know if I should >> separate it to litter patchs :) > > Yes, of course you need to break it up into smaller pieces. > > One per subsystem, make a large patch series, send it out, get a few > merged, refresh, send again, and keep going until all of the users are > out of the tree and then drop the old api call. That's how we do this > all the time, should take about 1 kernel release if you are quick and > lucky :) > > hope this helps, Yes, it do help. Thanks for your help. Yisheng Xie > > greg k-h > > . >