From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from relay2.sgi.com ([192.48.180.65] helo=relay.sgi.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XySto-0001L0-IK for kexec@lists.infradead.org; Tue, 09 Dec 2014 22:04:53 +0000 Received: from estes.americas.sgi.com (estes.americas.sgi.com [128.162.236.10]) by relay2.corp.sgi.com (Postfix) with ESMTP id 7C35030404E for ; Tue, 9 Dec 2014 14:04:27 -0800 (PST) Received: from eag09.americas.sgi.com (eag09.americas.sgi.com [128.162.232.15]) by estes.americas.sgi.com (Postfix) with ESMTP id CEE8C700350C for ; Tue, 9 Dec 2014 16:04:27 -0600 (CST) Received: from cpw by eag09.americas.sgi.com with local (Exim 4.76) (envelope-from ) id 1XyStP-0004rK-LJ for kexec@lists.infradead.org; Tue, 09 Dec 2014 16:04:27 -0600 Date: Tue, 9 Dec 2014 16:04:27 -0600 From: Cliff Wickman Subject: [PATCH 0/2] time and space saving patches for large memories Message-ID: <20141209220427.GA18652@sgi.com> MIME-Version: 1.0 Content-Disposition: inline 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" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: kexec@lists.infradead.org From: Cliff Wickman Back in early 2014 I submitted several patches for your consideration, most of which concerned saving time and disk space when dumping very large memories. I offer two of them again, as being the most important elements for the practical dumping of very large memories. [PATCH 1/2] use raw i/o and root device to use less memory [PATCH 2/2] exclude page structures of non-dumped pages The second patch has a few dependencies on the first. But they are logically separate. They apply to the 1.5.7 source. As an example of the importance of these two concepts: We dump a 2TB system using crashkernel=450M. Without the patches we write a 3.6G dump in about 12 minutes. With the patches we write a 590M dump in about 4 minutes. And the savings multiply as memory size grows. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec