Messages in this thread | | | Date | Sun, 30 Dec 2012 14:02:28 +0800 | From | Wen Congyang <> | Subject | Re: [PATCH v5 14/14] memory-hotplug: free node_data when a node is offlined |
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At 12/28/2012 08:28 AM, Kamezawa Hiroyuki Wrote: > (2012/12/27 21:16), Wen Congyang wrote: >> At 12/26/2012 11:55 AM, Kamezawa Hiroyuki Wrote: >>> (2012/12/24 21:09), Tang Chen wrote: >>>> From: Wen Congyang <wency@cn.fujitsu.com> >>>> >>>> We call hotadd_new_pgdat() to allocate memory to store node_data. So we >>>> should free it when removing a node. >>>> >>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >>> >>> I'm sorry but is it safe to remove pgdat ? All zone cache and zonelists are >>> properly cleared/rebuilded in synchronous way ? and No threads are visinting >>> zone in vmscan.c ? >> >> We have rebuilt zonelists when a zone has no memory after offlining some pages. >> > > How do you guarantee that the address of pgdat/zone is not on stack of any kernel > threads or other kernel objects without reference counting or other syncing method ?
No way to guarentee this. But, the kernel should not use the address of pgdat/zone when it is offlined.
Hmm, what about this: reuse the memory when the node is onlined again?
Thanks Wen Congyang
> > > Thanks, > -Kame > > >
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