From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from co1outboundpool.messaging.microsoft.com (co1ehsobe001.messaging.microsoft.com [216.32.180.184]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "MSIT Machine Auth CA 2" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 51D2E2C0335 for ; Fri, 12 Jul 2013 06:55:35 +1000 (EST) Message-ID: <51DF1BBB.5060904@mail.usask.ca> Date: Thu, 11 Jul 2013 14:55:23 -0600 From: Chris Friesen MIME-Version: 1.0 To: Vivek Goyal , Haren Myneni , , Benjamin Herrenschmidt , Paul Mackerras , Subject: visible memory seems wrong in kexec crash dump kernel Content-Type: text/plain; charset="ISO-8859-1" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, I'm running 2.6.34 with kexec 2.0.1 on a Freescale p5020-based system with 8GB of memory. (It's an embedded system and I can't do much about the fact that it's using older software.) I booted the original kernel with "crashkernel=224M@32M" in the boot args. I then loaded the crash kernel with: ./kexec -p vmlinux.kontron.strip --append="root=/dev/mtdblock0 rw rootfstype=jffs2 panic=5 1 maxcpus=1 noirqdistrib reset_devices" Then I triggered a crash: echo 1 > /proc/sys/kernel/sysrq echo c > /proc/sysrq-trigger When the crash kernel came up, it had "elfcorehdr=48392K savemaxmem=8192M" in the kernel boot args, and "free" showed the system as having 7908652 KB of total memory instead of the expected 224MB. Do I need to manually specify some options to kexec in order to preserve the memory of the original system? I seem to recall that kexec did this automatically on x86 systems. Thanks, Chris