Re: [PATCH 2/3] selftests/mm: put general ksm operation into vm_util

[David Hildenbrand <david@redhat.com>]

> My plan is there are two pairs of helper:
> 
>      ksm_merge()  <->  ksm_unmerge()
>      ksm_start_and_merge() <-> ksm_stop_and_unmerge()
> 
>> Probably we should just use ksm_stop_and_unmerge() and remove ksm_unmerge().
>>
> 
> Looks reasonable, will remove it.
> 
> So how about leave three helpers:
> 
>     ksm_merge()
>     ksm_start()
>     ksm_stop_and_unmerge()
> 
> Would this be better?

Is there utility for separating ksm_start() and ksm_merge() in current 
code and with what you are intending to do?

>>> +
>>> +int ksm_stop_and_unmerge()
>>> +{
>>> +	int ksm_fd;
>>> +	ssize_t ret;
>>> +
>>> +	ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR);
>>> +	if (ksm_fd < 0)
>>> +		return -1;
>>> +
>>> +	ret = write(ksm_fd, "2", 1);
>>> +	close(ksm_fd);
>>> +	return ret == 1 ?  0 : ret;
>>
>> double space
>>
> 
> Shame on me :-(

Not the end of the world ;)

-- 
Cheers,

David / dhildenb