From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f65.google.com (mail-wm0-f65.google.com [74.125.82.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qg1Mg6XMtzDq6B for ; Wed, 6 Apr 2016 19:56:30 +1000 (AEST) Received: by mail-wm0-f65.google.com with SMTP id o129so2169155wmo.3 for ; Wed, 06 Apr 2016 02:56:30 -0700 (PDT) Date: Wed, 6 Apr 2016 11:56:24 +0200 From: Michal Hocko To: Sukadev Bhattiprolu Cc: Michael Ellerman , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, James Dykman , "Aneesh Kumar K.V" Subject: Re: [PATCH 1/1] powerpc/mm: Add memory barrier in __hugepte_alloc() Message-ID: <20160406095623.GA24283@dhcp22.suse.cz> References: <20160405190547.GA12673@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160405190547.GA12673@us.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue 05-04-16 12:05:47, Sukadev Bhattiprolu wrote: [...] > diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c > index d991b9e..081f679 100644 > --- a/arch/powerpc/mm/hugetlbpage.c > +++ b/arch/powerpc/mm/hugetlbpage.c > @@ -81,6 +81,13 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, > if (! new) > return -ENOMEM; > > + /* > + * Make sure other cpus find the hugepd set only after a > + * properly initialized page table is visible to them. > + * For more details look for comment in __pte_alloc(). > + */ > + smp_wmb(); > + what is the pairing memory barrier? > spin_lock(&mm->page_table_lock); > #ifdef CONFIG_PPC_FSL_BOOK3E > /* > -- > 1.8.3.1 -- Michal Hocko SUSE Labs