Messages in this thread | | | Date | Mon, 9 Jan 2017 15:27:03 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v2] memory_hotplug: zone_can_shift() returns boolean value |
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On Tue, 13 Dec 2016 15:29:49 -0500 Yasuaki Ishimatsu <yasu.isimatu@gmail.com> wrote:
> online_{kernel|movable} is used to change the memory zone to > ZONE_{NORMAL|MOVABLE} and online the memory. > > To check that memory zone can be changed, zone_can_shift() is used. > Currently the function returns minus integer value, plus integer > value and 0. When the function returns minus or plus integer value, > it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}. > > But when the function returns 0, there is 2 meanings. > > One of the meanings is that the memory zone does not need to be changed. > For example, when memory is in ZONE_NORMAL and onlined by online_kernel > the memory zone does not need to be changed. > > Another meaning is that the memory zone cannot be changed. When memory > is in ZONE_NORMAL and onlined by online_movable, the memory zone may > not be changed to ZONE_MOVALBE due to memory online limitation(see > Documentation/memory-hotplug.txt). In this case, memory must not be > onlined. > > The patch changes the return type of zone_can_shift() so that memory > is not onlined when memory zone cannot be changed.
What are the user-visible runtime effects of this fix?
Please always include this info when fixing bugs - it is required so that others can decide which kernel version(s) need the fix.
Thanks.
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