Re: [PATCH 07/14] vrange: Purge volatile pages when memory is tight

John Stultz
2013-10-08T16:23:19Z

On 10/07/2013 08:27 PM, Zhan Jianyu wrote:
> On Thu, Oct 3, 2013 at 8:51 AM, John Stultz <john.stultz@linaro.org> wrote:
>> static inline int page_referenced(struct page *page, int is_locked,
>> struct mem_cgroup *memcg,
>> - unsigned long *vm_flags)
>> + unsigned long *vm_flags,
>> + int *is_vrange)
>> {
>> *vm_flags = 0;
>> + *is_vrange = 0;
>> return 0;
>> }
> I don't know if it is appropriate to add a parameter in such a core
> function for an optional functionality. Maybe the is_vrange flag
> should be squashed into the vm_flags ? I am not sure .
Yea, this wasn't either Minchan or I were particularly fond of, but with
the vm_flags exausted, there wasn't a clear way to do so without doing
the rmap traversal again.

Other suggestions? Extending the vm_flags to 64bits is something many
better mm devs have tried to merge unsuccessfully, so I'm hesitant to
try pushing it myself.

thanks
-john