From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f179.google.com (mail-wi0-f179.google.com [209.85.212.179]) by kanga.kvack.org (Postfix) with ESMTP id AFD32900021 for ; Tue, 28 Oct 2014 06:55:05 -0400 (EDT) Received: by mail-wi0-f179.google.com with SMTP id h11so1126159wiw.12 for ; Tue, 28 Oct 2014 03:55:05 -0700 (PDT) Received: from jenni2.inet.fi (mta-out1.inet.fi. [62.71.2.194]) by mx.google.com with ESMTP id di9si13831441wib.52.2014.10.28.03.55.03 for ; Tue, 28 Oct 2014 03:55:04 -0700 (PDT) Date: Tue, 28 Oct 2014 12:54:58 +0200 From: "Kirill A. Shutemov" Subject: Re: Progress on system crash traces with LTTng using DAX and pmem Message-ID: <20141028105458.GA9768@node.dhcp.inet.fi> References: <1254279794.1957.1414240389301.JavaMail.zimbra@efficios.com> <465653369.1985.1414241485934.JavaMail.zimbra@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <465653369.1985.1414241485934.JavaMail.zimbra@efficios.com> Sender: owner-linux-mm@kvack.org List-ID: To: Mathieu Desnoyers Cc: Matthew Wilcox , Ross Zwisler , lttng-dev , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Sat, Oct 25, 2014 at 12:51:25PM +0000, Mathieu Desnoyers wrote: > FYI, the main reason why my customer wants to go with a > "trace into memory that survives soft reboot" approach > rather than to use things like kexec/kdump is that they > care about the amount of time it takes to reboot their > machines. They want a solution where they can extract the > detailed crash data after reboot, after the machine is > back online, rather than requiring a few minutes of offline > time to extract the crash details. IIRC, on x86 there's no guarantee that your memory content will be preserved over reboot. BIOS is free to mess with it. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org