Re: [PATCH v2 3/7] x86, gfp: Cache best near node for memory allocation.

[Tang Chen <tangchen@cn.fujitsu.com>]

Hi, Christoph, tj,

On 09/11/2015 08:14 AM, Christoph Lameter wrote:
> On Thu, 10 Sep 2015, Tejun Heo wrote:
>
>>> Why not just update node_data[]->node_zonelist in the first place?
>>> Also, what's the synchronization rule here?  How are allocators
>>> synchronized against node hot [un]plugs?
>> Also, shouldn't kmalloc_node() or any public allocator fall back
>> automatically to a near node w/o GFP_THISNODE?  Why is this failing at
>> all?  I get that cpu id -> node id mapping changing messes up the
>> locality but allocations shouldn't fail, right?

Yes. That is the reason we are getting near online node here.

> Yes that should occur in the absence of other constraints (mempolicies,
> cpusets, cgroups, allocation type). If the constraints do not allow an
> allocation then the allocation will fail.
>
> Also: Are the zonelists setup the right way?

zonelist will be rebuilt in __offline_pages() when the zone is not 
populated any more.

Thanks.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>