Messages in this thread | | | Date | Mon, 3 Feb 2014 16:06:51 -0800 (PST) | From | David Rientjes <> | Subject | Re: Need help in bug in isolate_migratepages_range |
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On Mon, 3 Feb 2014, Vlastimil Babka wrote:
> It seems to come from balloon_page_movable() and its test page_count(page) == > 1. >
Hmm, I think it might be because compound_head() == NULL here. Holger, this looks like a race condition when allocating a compound page, did you only see it once or is it actually reproducible?
I think this happens when a new compound page is allocated and PageBuddy is cleared before prep_compound_page() and then we see PageTail(p) set but p->first_page is not yet initialized. Is there any way to avoid memory barriers in compound_page()?
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