Messages in this thread | | | Date | Wed, 21 Sep 2016 14:05:08 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH] memory-hotplug: Fix bad area access on dissolve_free_huge_pages() |
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On Tue 20-09-16 10:43:13, Dave Hansen wrote: > On 09/20/2016 08:52 AM, Rui Teng wrote: > > On 9/20/16 10:53 PM, Dave Hansen wrote: > ... > >> That's good, but aren't we still left with a situation where we've > >> offlined and dissolved the _middle_ of a gigantic huge page while the > >> head page is still in place and online? > >> > >> That seems bad. > >> > > What about refusing to change the status for such memory block, if it > > contains a huge page which larger than itself? (function > > memory_block_action()) > > How will this be visible to users, though? That sounds like you simply > won't be able to offline memory with gigantic huge pages.
I might be missing something but Is this any different from a regular failure when the memory cannot be freed? I mean /sys/devices/system/memory/memory API doesn't give you any hint whether the memory in the particular block is used and unmigrateable.
-- Michal Hocko SUSE Labs
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