Messages in this thread | | | Date | Thu, 10 Jan 2013 09:38:10 +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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Hi Glauber,
On 01/09/2013 11:09 PM, Glauber Costa wrote: >> >> We try to make all page_cgroup allocations local to the node they are describing >> now. If the memory is the first memory onlined in this node, we will allocate >> it from the other node. >> >> For example, node1 has 4 memory blocks: 8-11, and we online it from 8 to 11 >> 1. memory block 8, page_cgroup allocations are in the other nodes >> 2. memory block 9, page_cgroup allocations are in memory block 8 >> >> So we should offline memory block 9 first. But we don't know in which order >> the user online the memory block. >> >> I think we can modify memcg like this: >> allocate the memory from the memory block they are describing >> >> I am not sure it is OK to do so. > > I don't see a reason why not.
I'm not sure, but if we do this, we could bring in a fragment for each memory block (a memory section, 128MB, right?). Is this a problem when we use large page (such as 1GB page) ?
Even if not, will these fragments make any bad effects ?
Thank. :)
> > You would have to tweak a bit the lookup function for page_cgroup, but > assuming you will always have the pfns and limits, it should be easy to do. > > I think the only tricky part is that today we have a single > node_page_cgroup, and we would of course have to have one per memory > block. My assumption is that the number of memory blocks is limited and > likely not very big. So even a static array would do. > > Kamezawa, do you have any input in here? >
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