Messages in this thread | | | Subject | Re: [PATCH v2 10/10] thp: implement refcounting for huge zero page | From | Eric Dumazet <> | Date | Mon, 10 Sep 2012 16:57:59 +0200 |
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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 :
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();
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