Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751891Ab3FYQDD (ORCPT ); Tue, 25 Jun 2013 12:03:03 -0400 Received: from mga14.intel.com ([143.182.124.37]:60268 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242Ab3FYQDB convert rfc822-to-8bit (ORCPT ); Tue, 25 Jun 2013 12:03:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,938,1363158000"; d="scan'208";a="322365827" From: "Luck, Tony" To: Aruna Balakrishnaiah , Kees Cook CC: "jkenisto@linux.vnet.ibm.com" , Colin Cross , LKML , Anton Vorontsov , "linuxppc-dev@ozlabs.org" , "paulus@samba.org" , "Anton Blanchard" , "mahesh@linux.vnet.ibm.com" Subject: RE: [PATCH 3/3] powerpc/pseries: Support compression of oops text via pstore Thread-Topic: [PATCH 3/3] powerpc/pseries: Support compression of oops text via pstore Thread-Index: AQHOcKOFI+fbT3qTAkWgSP4nHd50LJlFnK6AgADb4ICAAB740A== Date: Tue, 25 Jun 2013 16:02:58 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F31C5376F@ORSMSX106.amr.corp.intel.com> References: <20130624061936.12963.72529.stgit@aruna-ThinkPad-T420> <20130624062316.12963.87911.stgit@aruna-ThinkPad-T420> <51C94101.3030702@linux.vnet.ibm.com> In-Reply-To: <51C94101.3030702@linux.vnet.ibm.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.140] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1165 Lines: 24 > Introducing headersize in pstore_write() API would need changes at > multiple places whereits being called. The idea is to move the > compression support to pstore infrastructure so that other platforms > could also make use of it. Any thoughts on the back/forward compatibility as we switch to compressed pstore data? E.g. imagine I have a system installed with some Linux distribution with a kernel too old to know about compressed pstore. I use that machine to run the latest kernels that do compression ... and one fine day one of them crashes hard - logging in compressed form to pstore. Now I boot my distro kernel to pick up the pieces ... what do I see in /sys/fs/pstore/*? Some compressed files? Can I read them with some tool? This somewhat of a corner case - but not completely unrealistic ... I'd at least like to be reassured that the old kernel won't choke when it sees the compressed blobs. -Tony -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/