Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755263Ab2JVQdL (ORCPT ); Mon, 22 Oct 2012 12:33:11 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:59963 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820Ab2JVQdI (ORCPT ); Mon, 22 Oct 2012 12:33:08 -0400 MIME-Version: 1.0 In-Reply-To: <20121022142143.GC14193@konrad-lan.dumpdata.com> References: <1350593430-24470-1-git-send-email-yinghai@kernel.org> <1350593430-24470-5-git-send-email-yinghai@kernel.org> <20121022142143.GC14193@konrad-lan.dumpdata.com> Date: Mon, 22 Oct 2012 09:33:07 -0700 X-Google-Sender-Auth: xT2vXQtFljija2Y8Kxb50l69rtU Message-ID: Subject: Re: [PATCH 02/19] x86, mm: Use big page size for small memory range From: Yinghai Lu To: Konrad Rzeszutek Wilk Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Jacob Shin , Tejun Heo , Stefano Stabellini , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1193 Lines: 30 On Mon, Oct 22, 2012 at 7:21 AM, Konrad Rzeszutek Wilk wrote: > On Thu, Oct 18, 2012 at 01:50:12PM -0700, Yinghai Lu wrote: >> We could map small range in the middle of big range at first, so should use >> big page size at first to avoid using small page size to break down page table. >> >> Only can set big page bit when that range has ram area around it. > > The code looks good. > > I would alter the description to say: > > (Describe the problem) > > "We are wasting entries in the page-table b/c are not taking advantage > of the fact that adjoining ranges could be of the same type and > coalescing them together. Instead we end up using the small size type." > > (Explain your patch). > > "We fix this by iterating over the ranges, detecting whether the > ranges that are next to each other are of the same type - and if so > set them to our type." I think my commit change log is clear enough, and will not update it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/