On 02/06/2013 10:24 PM, Glauber Costa wrote:

quoted

quoted

quoted

And one more question, a memory section is 128MB in Linux. If we reserve
part of the them for page_cgroup,
then anyone who wants to allocate a contiguous memory larger than 128MB,
it will fail, right ?
Is it OK ?

No, it is not.

Another take on this: Can't we free all the page_cgroup structure before
we actually start removing the sections ? If we do this, we would be
basically left with no problem at all, since when your code starts
running we would no longer have any page_cgroup allocated.

All you have to guarantee is that it happens after the memory block is
already isolated and allocations no longer can reach it.

What do you think ?

Hi Glauber,

I don't think so. We can offline some of the sections and leave the 
reset online.

For example, we store page_cgroups of memory9~11 in memory8. So when we 
offline memory8,
we free memory8's page_cgroup storing on other section, but we cannot 
free the page_cgroups
being stored in memory8 if memory9~11 are left online.

So we still need to offline memory9~11, and then offline memory8, right ?
I think it makes no difference.

Thanks. :)