From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id B2FEC6B0069 for ; Mon, 10 Sep 2012 11:07:15 -0400 (EDT) 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 Message-ID: <20120910150747.GA23556@shutemov.name> References: <1347282813-21935-1-git-send-email-kirill.shutemov@linux.intel.com> <1347282813-21935-11-git-send-email-kirill.shutemov@linux.intel.com> <1347285759.1234.1645.camel@edumazet-glaptop> <20120910144438.GA31697@otc-wbsnb-06> <1347289079.1234.1706.camel@edumazet-glaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1347289079.1234.1706.camel@edumazet-glaptop> Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli , linux-mm@kvack.org, Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org