Re: [PATCH 5 of 6] hotplug-memory: add section_ops

[Jeremy Fitzhardinge <jeremy@goop.org>]

KAMEZAWA Hiroyuki wrote:
> On Thu, 03 Apr 2008 17:51:12 -0700
> Dave Hansen <dave@linux.vnet.ibm.com> wrote:
>
>   
>> On Thu, 2008-04-03 at 17:05 -0700, Jeremy Fitzhardinge wrote:
>>     
>>> Add a per-section "section_ops" structure,  allowing each section to have
>>> specific functions for onlining and offlining pages within the section.
>>> This is used by the Xen balloon driver to make sure that pages are not
>>> onlined without some physical memory backing them.
>>>       
>> This is kinda a lot of code and mucking around for what we actually get
>> out of it, especially since you just condensed down all the actual
>> online_page() instances.
>>
>> I think it might just be nicer to have a global list of these handlers
>> somewhere.  The Xen driver can just say "put me on the list of
>> callbacks" and we'll call them at online_page().  I really don't think
>> we need to be passing an ops structure around.
>>
>> KAME, did you have some other ideas about this?
>>
>>     
>
> At first. please don't call online_page() handler in add_memory() phase.
> online_page() handler should be called in online_pages().
>   

Yes, that's how it is at the moment.

> Passing handler to online_pages() is much easier and it's ok to me.
>   

Rather than an ops structure associated with the section?  That's a 
possibility...  I'll see how that looks...

    J