Messages in this thread |  | | Date | Mon, 20 Apr 2015 10:09:08 +0800 | From | Gu Zheng <> | Subject | Re: [PATCH 1/2 V2] memory-hotplug: fix BUG_ON in move_freepages() |
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Hi Ishimatsu, Xishi,
On 04/20/2015 10:11 AM, Yasuaki Ishimatsu wrote:
> >> When hot adding memory and creating new node, the node is offline. >> And after calling node_set_online(), the node becomes online. >> >> Oh, sorry. I misread your ptaches. >> > > Please ignore it...
Seems also a misread to me. I clear it (my worry) here: If we set the node size to 0 here, it may hidden more things than we experted. All the init chunks around with the size (spanned/present/managed...) will be non-sense, and the user/caller will not get a summary of the hot added node because of the changes here. I am not sure the worry is necessary, please correct me if I missing something.
Regards, Gu
> > Thanks, > Yasuaki Ishimatsu > > On > Yasuaki Ishimatsu <yasu.isimatu@gmail.com> wrote: > >> >> When hot adding memory and creating new node, the node is offline. >> And after calling node_set_online(), the node becomes online. >> >> Oh, sorry. I misread your ptaches. >> >> Thanks, >> Yasuaki Ishimatsu >> >> On Mon, 20 Apr 2015 09:33:10 +0800 >> Xishi Qiu <qiuxishi@huawei.com> wrote: >> >>> On 2015/4/18 4:05, Yasuaki Ishimatsu wrote: >>> >>>> >>>> Your patches will fix your issue. >>>> But, if BIOS reports memory first at node hot add, pgdat can >>>> not be initialized. >>>> >>>> Memory hot add flows are as follows: >>>> >>>> add_memory >>>> ... >>>> -> hotadd_new_pgdat() >>>> ... >>>> -> node_set_online(nid) >>>> >>>> When calling hotadd_new_pgdat() for a hot added node, the node is >>>> offline because node_set_online() is not called yet. So if applying >>>> your patches, the pgdat is not initialized in this case. >>>> >>>> Thanks, >>>> Yasuaki Ishimatsu >>>> >>> >>> Hi Yasuaki, >>> >>> I'm not quite understand, when BIOS reports memory first, why pgdat >>> can not be initialized? >>> When hotadd a new node, hotadd_new_pgdat() will be called too, and >>> when hotadd memory to a existent node, it's no need to call hotadd_new_pgdat(), >>> right? >>> >>> Thanks, >>> Xishi Qiu >>> > . >
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