From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752617AbbJSB7q (ORCPT ); Sun, 18 Oct 2015 21:59:46 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:53290 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752416AbbJSB7p (ORCPT ); Sun, 18 Oct 2015 21:59:45 -0400 Subject: Re: [RFD] pstore: pmsg: ramoops: add multiple pmsg instances To: Mark Salyzyn , , , , , , LKML References: <56171DF4.2030209@hitachi.com> <5617E806.7020407@android.com> From: Hiraku Toyooka Message-ID: <56244E8D.5040303@hitachi.com> Date: Mon, 19 Oct 2015 10:59:41 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <5617E806.7020407@android.com> Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.232.31.66] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Mark, (I'm sorry for my late reply.) Mark Salyzyn wrote: >> I'm trying to make the feature of multiple pmsg instances for ramoops. > I like it, in fact I encourage it. Thank you. > Multiple instances does allow one to control individual content aging or > priority, I agree with your assessment, but make sure that you have a > bona fide user for it (even if it is just for yourself)? Yes. There are embedded devices which have limited NVRAM and no HDD/SSD. Especially in our usage, the devices are industrial machinery. When we catch a system failure, for fixing the root cause of the failure, we often have to distinguish if it happend suddenly or if there were signs long before the failure. Multiple pmsg can help this kind of cause analysis with small NVRAM because higher priority messages are preserved for a long time. > NB: ToDo: device tree support for pstore configuration Would you mean pstore backend's configuration (e.g.'mem_address' in ramoops)? Best regards, Hiraku Toyooka