From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754601Ab2EOGHl (ORCPT ); Tue, 15 May 2012 02:07:41 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:33732 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753833Ab2EOGHk convert rfc822-to-8bit (ORCPT ); Tue, 15 May 2012 02:07:40 -0400 MIME-Version: 1.0 In-Reply-To: <1337013022.2476.17.camel@lorien2> References: <20120512001506.GA8653@lizard> <20120514155846.GA19538@kroah.com> <1337013022.2476.17.camel@lorien2> Date: Tue, 15 May 2012 08:07:38 +0200 Message-ID: Subject: Re: [PATCH 0/11] Merge ramoops and persistent_ram, generic pstore RAM backend From: Marco Stornelli To: shuahkhan@gmail.com Cc: Greg Kroah-Hartman , Anton Vorontsov , Kees Cook , Colin Cross , devel@driverdev.osuosl.org, linaro-kernel@lists.linaro.org, Arnd Bergmann , patches@linaro.org, Stephen Boyd , Sergiu Iordache , linux-kernel@vger.kernel.org, arve@android.com, Jesper Juhl , John Stultz , Rebecca Schultz Zavin , WANG Cong , Andrew Morton , kernel-team@android.com, Thomas Meyer , tony.luck@intel.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2012/5/14 Shuah Khan : > On Mon, 2012-05-14 at 08:58 -0700, Greg Kroah-Hartman wrote: >> On Fri, May 11, 2012 at 05:15:06PM -0700, Anton Vorontsov wrote: >> > Hi all, >> > >> > There are currently two competing debug facilities to store kernel >> > messages in a persistent storage: a generic pstore and Google's >> > persistent_ram. Not so long ago (https://lkml.org/lkml/2012/3/8/252), >> > it was decided that we should fix this situation. >> > >> > Recently ramoops has switched to pstore, which basically means that >> > it became a RAM backend for the pstore framework. >> > >> > persistent_ram+ram_console and ramoops+pstore have almost the same >> > features, except: >> > >> > 1. Ramoops doesn't support ECC. Having ECC is useful when a hardware >> >    reset was used to bring the machine back to life (i.e. a watchdog >> >    triggered). In such cases, RAM may be somewhat corrupt, but >> >    usually it is restorable. >> > >> > 2. Pstore doesn't support logging kernel messages in run-time, it only >> >    dumps dmesg when kernel oopses/panics. This makes pstore useless for >> >    debugging hangs caused by HW issues or improper use of HW (e.g. >> >    weird device inserted -> driver tried to write a reserved bits -> >> >    SoC hanged. In that case we don't get any messages in the pstore. >> > >> > These patches solve the first issue, plus move things to their >> > proper places. Patches that will fix the second issue are pending. >> >> I've applied the first 7 patches, as they were localized to the >> drivers/staging/android/ directory, but in order for me to apply the >> rest, I need acks from the respective subsystem maintainers. >> >> pstore developers, what do you say about these changes, are you ok with >> them? > > Good to see this work get done. Anton beat me to it. :) I have been > talking to pstore developers (Tony Luck) and ramoops maintainers (Kees > Cook) about this re-architecture work since I first floated this idea on > ce-android mailing list. I have been working on this rec-architecture > focusing on the second feature "Pstore doesn't support logging kernel > messages in run-time" and didn't get to ECC even though it is on my > feature list to do bring ramconsole features into ramoops. > > Anton! Is it safe to assume you are planning to cover the second feature > as well, in which case I can drop my plans to get this work done. > > -- Shuah >> >> thanks, >> >> greg k-h >> -- My ack for ramoops patches. You can add my acked-by. Marco