Messages in this thread | | | Date | Thu, 07 Feb 2013 15:56:35 +0800 | From | Tang Chen <> | Subject | Re: [PATCH v5 01/14] memory-hotplug: try to offline the memory twice to avoid dependence |
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On 02/06/2013 10:24 PM, Glauber Costa wrote: >>>> 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. :)
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