From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f53.google.com (mail-qa0-f53.google.com [209.85.216.53]) by kanga.kvack.org (Postfix) with ESMTP id 62E496B0031 for ; Sat, 4 Jan 2014 02:31:52 -0500 (EST) Received: by mail-qa0-f53.google.com with SMTP id j5so1251297qaq.5 for ; Fri, 03 Jan 2014 23:31:52 -0800 (PST) Received: from mail-pa0-x236.google.com (mail-pa0-x236.google.com [2607:f8b0:400e:c03::236]) by mx.google.com with ESMTPS id p3si61935178qah.18.2014.01.03.23.31.50 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 03 Jan 2014 23:31:51 -0800 (PST) Received: by mail-pa0-f54.google.com with SMTP id rd3so16533281pab.41 for ; Fri, 03 Jan 2014 23:31:50 -0800 (PST) Date: Sat, 4 Jan 2014 07:31:43 +0000 From: Minchan Kim Subject: Re: [RFC PATCHv3 00/11] Intermix Lowmem and vmalloc Message-ID: <20140104073143.GA5594@gmail.com> References: <1388699609-18214-1-git-send-email-lauraa@codeaurora.org> <52C70024.1060605@sr71.net> <52C734F4.5020602@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52C734F4.5020602@codeaurora.org> Sender: owner-linux-mm@kvack.org List-ID: To: Laura Abbott Cc: Dave Hansen , Andrew Morton , Kyungmin Park , linux-mm@kvack.org, Russell King , linux-kernel@vger.kernel.org Hello, On Fri, Jan 03, 2014 at 02:08:52PM -0800, Laura Abbott wrote: > On 1/3/2014 10:23 AM, Dave Hansen wrote: > >On 01/02/2014 01:53 PM, Laura Abbott wrote: > >>The goal here is to allow as much lowmem to be mapped as if the block of memory > >>was not reserved from the physical lowmem region. Previously, we had been > >>hacking up the direct virt <-> phys translation to ignore a large region of > >>memory. This did not scale for multiple holes of memory however. > > > >How much lowmem do these holes end up eating up in practice, ballpark? > >I'm curious how painful this is going to get. > > > > In total, the worst case can be close to 100M with an average case > around 70M-80M. The split and number of holes vary with the layout > but end up with 60M-80M one hole and the rest in the other. One more thing I'd like to know is how bad direct virt <->phys tranlsation in scale POV and how often virt<->phys tranlsation is called in your worload so what's the gain from this patch? Thanks. -- 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