From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932263Ab2IMRQV (ORCPT ); Thu, 13 Sep 2012 13:16:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32023 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754960Ab2IMRQT (ORCPT ); Thu, 13 Sep 2012 13:16:19 -0400 Date: Thu, 13 Sep 2012 19:16:13 +0200 From: Andrea Arcangeli To: "Kirill A. Shutemov" Cc: Andrew Morton , linux-mm@kvack.org, Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [PATCH v3 10/10] thp: implement refcounting for huge zero page Message-ID: <20120913171613.GJ3388@redhat.com> References: <1347282813-21935-1-git-send-email-kirill.shutemov@linux.intel.com> <1347444473-26468-1-git-send-email-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1347444473-26468-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kirill, On Wed, Sep 12, 2012 at 01:07:53PM +0300, Kirill A. Shutemov wrote: > - hpage = alloc_pages(GFP_TRANSHUGE | __GFP_ZERO, HPAGE_PMD_ORDER); The page is likely as large as a pageblock so it's unlikely to create much fragmentation even if the __GFP_MOVABLE is set. Said that I guess it would be more correct if __GFP_MOVABLE was clear, like (GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE because this page isn't really movable (it's only reclaimable). The xchg vs xchgcmp locking also looks good. Reviewed-by: Andrea Arcangeli Thanks, Andrea