Re: [RFC]kvm: swapout guest page

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Carsten Otte wrote:
> Shaohua Li wrote:
>   
>> +EXPORT_SYMBOL(delete_from_swap_cache);
>> +EXPORT_SYMBOL(move_to_swap_cache);
>> +EXPORT_SYMBOL(lookup_swap_cache);
>> +EXPORT_SYMBOL(read_swap_cache_async);
>> +EXPORT_SYMBOL(get_swap_page);
>> +EXPORT_SYMBOL(swap_free);
>> +EXPORT_SYMBOL(add_to_page_cache_lru);
>>     
> Use EXPORT_SYMBOL_GPL for all of these.
>
> I fail to see, why this is needed at all. Regular malloc()ed userspace 
> memory should be just what we want? The s390host prototype does just 
> that, userspace uses malloc() and the memory will be swapped out just 
> regular. Am I missing something important?
>   

For one thing, kvm uses page->private to store its rmap information.  
This is lost if regular mappings are used.

More importantly, both the regular address space and kvm will want to be 
called when a page is paged out, while this is doable, it isn't easy.

-- 
error compiling committee.c: too many arguments to function


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