From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755636Ab3KFBxv (ORCPT ); Tue, 5 Nov 2013 20:53:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33648 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752269Ab3KFBxu (ORCPT ); Tue, 5 Nov 2013 20:53:50 -0500 Date: Tue, 5 Nov 2013 20:53:14 -0500 From: Vivek Goyal To: Jingbai Ma Cc: ptesarik@suse.cz, d.hatayama@jp.fujitsu.com, kumagai-atsushi@mxc.nes.nec.co.jp, bhe@redhat.com, tom.vaden@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, lisa.mitchell@hp.com, anderson@redhat.com, ebiederm@xmission.com Subject: Re: [PATCH 0/3] makedumpfile: hugepage filtering for vmcore dump Message-ID: <20131106015314.GA17923@redhat.com> References: <20131105134532.32112.78008.stgit@k.asiapacific.hpqcorp.net> <20131105202631.GC4598@redhat.com> <52799FC5.5040408@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52799FC5.5040408@hp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 06, 2013 at 09:47:49AM +0800, Jingbai Ma wrote: > On 11/06/2013 04:26 AM, Vivek Goyal wrote: > >On Tue, Nov 05, 2013 at 09:45:32PM +0800, Jingbai Ma wrote: > >>This patch set intend to exclude unnecessary hugepages from vmcore dump file. > >> > >>This patch requires the kernel patch to export necessary data structures into > >>vmcore: "kexec: export hugepage data structure into vmcoreinfo" > >>http://lists.infradead.org/pipermail/kexec/2013-November/009997.html > >> > >>This patch introduce two new dump levels 32 and 64 to exclude all unused and > >>active hugepages. The level to exclude all unnecessary pages will be 127 now. > > > >Interesting. Why hugepages should be treated any differentely than normal > >pages? > > > >If user asked to filter out free page, then it should be filtered and > >it should not matter whether it is a huge page or not? > > Yes, free hugepages should be filtered out with other free pages. It > sounds reasonable. > > But for active hugepages, I would offer user more > choices/flexibility. (maybe bad). > I'm OK to filter active hugepages with other user data page. > > Any other comments? I really can't see why hugepages are different than regular pages when it comes to filtering. IMO, we really should not create filtering option/levels only for huge pages, until and unless there is a strong use case. Thanks Vivek