From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932529AbcCHJgr (ORCPT ); Tue, 8 Mar 2016 04:36:47 -0500 Received: from ozlabs.org ([103.22.144.67]:52301 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932324AbcCHJgm (ORCPT ); Tue, 8 Mar 2016 04:36:42 -0500 Message-ID: <1457429794.31524.1.camel@ellerman.id.au> Subject: Re: [PATCH 2/2] powerpc/mm: Enable page parallel initialisation From: Michael Ellerman To: Li Zhang , akpm@linux-foundation.org, vbabka@suse.cz, mgorman@techsingularity.net, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Li Zhang Date: Tue, 08 Mar 2016 20:36:34 +1100 In-Reply-To: <1457409354-10867-3-git-send-email-zhlcindy@gmail.com> References: <1457409354-10867-1-git-send-email-zhlcindy@gmail.com> <1457409354-10867-3-git-send-email-zhlcindy@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5-1ubuntu3.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Li, On Tue, 2016-03-08 at 11:55 +0800, Li Zhang wrote: > From: Li Zhang > > Parallel initialisation has been enabled for X86, boot time is > improved greatly. On Power8, it is improved greatly for small > memory. Here is the result from my test on Power8 platform: > > For 4GB memory: 57% is improved, boot time as the following: > with patch: 10s, without patch: 24.5s This isn't worded quite right, and the numbers are a bit off. old = 24.5 new = 10 So the improvement is 14.5 (seconds). That means the improvement (14.5) as a percentage of the original boot time is: = 14.5 / 24.5 * 100 = 59.183673469387756 = 59% So you would say: For 4GB of memory, boot time is improved by 59%, from 24.5s to 10s. > For 50GB memory: 22% is improved, boot time as the following: > with patch: 43.8s, without patch: 56.8s For 50GB memory, boot time is improved by 22%, from 56.8s to 43.8s. > Acked-by: Mel Gorman > Signed-off-by: Li Zhang > --- > * Add boot time details in change log. > * Please apply this patch after [PATCH 1/2] mm: meminit: initialise > more memory for inode/dentry hash tables in early boot, because > [PATCH 1/2] is to fix a bug which can be reproduced on Power. Given that, I think it would be best if Andrew merged both of these patches. Because this patch is pretty trivial, whereas the patch to mm/ is less so. Is that OK Andrew? For this one: Acked-by: Michael Ellerman cheers