Messages in this thread | | | Date | Mon, 10 Sep 2012 18:07:47 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH v2 10/10] thp: implement refcounting for huge zero page |
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On Mon, Sep 10, 2012 at 04:57:59PM +0200, Eric Dumazet wrote: > On Mon, 2012-09-10 at 17:44 +0300, Kirill A. Shutemov wrote: > > > > Yes, disabling preemption before alloc_pages() and enabling after > > atomic_set() looks reasonable. Thanks. > > In fact, as alloc_pages(GFP_TRANSHUGE | __GFP_ZERO, HPAGE_PMD_ORDER); > might sleep, it would be better to disable preemption after calling it :
Yeah, I've alread thought about that. :)
> zero_page = alloc_pages(GFP_TRANSHUGE | __GFP_ZERO, HPAGE_PMD_ORDER); > if (!zero_page) > return 0; > preempt_disable(); > if (cmpxchg(&huge_zero_pfn, 0, page_to_pfn(zero_page))) { > preempt_enable(); > __free_page(zero_page); > goto retry; > } > atomic_set(&huge_zero_refcount, 2); > preempt_enable(); > >
-- Kirill A. Shutemov
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