From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SDFM9-0006uf-Uj for kexec@lists.infradead.org; Thu, 29 Mar 2012 13:25:39 +0000 Date: Thu, 29 Mar 2012 09:25:33 -0400 From: Don Zickus Subject: Re: makedumpfile memory usage grows with system memory size Message-ID: <20120329132533.GM18218@redhat.com> References: <20120328212204.GI18218@redhat.com> <20120329170918.4223e816.oomichi@mxs.nes.nec.co.jp> <20120329.215646.28793982.d.hatayama@jp.fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120329.215646.28793982.d.hatayama@jp.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: oomichi@mxs.nes.nec.co.jp, kexec@lists.infradead.org Hello Daisuke, On Thu, Mar 29, 2012 at 09:56:46PM +0900, HATAYAMA Daisuke wrote: > Hello Don, > > I'm missing your mail somehow so replying Oomichi-san's mail... > > From: "Ken'ichi Ohmichi" > Subject: Re: makedumpfile memory usage grows with system memory size > Date: Thu, 29 Mar 2012 17:09:18 +0900 > > > > > On Wed, 28 Mar 2012 17:22:04 -0400 > > Don Zickus wrote: > > >> I was curious if that was true and if it was, would it be possible to only > >> process memory in chunks instead of all at once. > >> > >> The idea is that a machine with 4Gigs of memory should consume the same > >> the amount of kdump runtime memory as a 1TB memory system. > >> > >> Just trying to research ways to keep the memory requirements consistent > >> across all memory ranges. > > I think this is possible in constant memory space by creating bitmaps > and writing pages in a certain amount of memory. That is, if choosing > 4GB, do [0, 4GB) space processing, [4GB, 8GB) space processing, [8GB, > 12GB) ... in order. The key is to restrict the target memory range of > filtering. Yes, that was what I was thinking. I am glad to hear that is possible. Is there some place in the code that I can help try out that idea? I would also be curious if there is a 'time' impact on how long it takes to process this (for example, would it add a couple of milliseconds overhead or seconds overhead). Thanks, Don _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec