Re: [PATCH v2] devres: use MACRO instead of function for devm_ioremap

[Yisheng Xie]

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
> 
> .
>