From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp07.in.ibm.com (e28smtp07.in.ibm.com [122.248.162.7]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp07.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id D5A9F2C00A7 for ; Thu, 6 Jun 2013 05:01:09 +1000 (EST) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Jun 2013 00:24:43 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id B46BBE004C for ; Thu, 6 Jun 2013 00:33:51 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r55J0wEg1835510 for ; Thu, 6 Jun 2013 00:30:58 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r55J11Op001869 for ; Thu, 6 Jun 2013 05:01:03 +1000 Message-ID: <51AF8AEA.4030702@linux.vnet.ibm.com> Date: Thu, 06 Jun 2013 00:30:58 +0530 From: Aruna Balakrishnaiah MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org, paulus@samba.org, linux-kernel@vger.kernel.org, benh@kernel.crashing.org Subject: Re: [RFC PATCH 0/3] Nvram-to-pstore: compression support for oops data References: <20130426094923.14323.80567.stgit@aruna-ThinkPad-T420> In-Reply-To: <20130426094923.14323.80567.stgit@aruna-ThinkPad-T420> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: jkenisto@linux.vnet.ibm.com, tony.luck@intel.com, keescook@chromium.org, mahesh@linux.vnet.ibm.com, cbouatmailru@gmail.com, anton@samba.org, ccross@android.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Ben, There is no change in this patchset and it applies cleanly on top of v4 of Nvram-to-pstorepatches. > The patchset takes care of compressing oops messages while writing to NVRAM, > so that more oops data can be captured in the given space. > > big_oops_buf (2.22 * oops_data_sz) is allocated for compression. > oops_data_sz is oops header size less of oops partition size. > > Pstore will internally call kmsg_dump to capture messages from printk > buffer. While returning the data to nvram it adds is own header. > > For compression: > Register pstore with big_oops_buf. > > In case compression fails, copy header added by pstore and > last oops_data_sz bytes (recent messages) of big_oops_buf to > nvram for which we need to know header size. > > patch 01/03 will add a function in pstore to return the header size. > > pstore read callback of nvram will read the compressed data and return the > decompressed data so that dmesg file (under /dev/pstore) is readable. > > In case decompression fails, instead of having the compressed data (junk) in the > dmesg file it will skip and continue reading other partitions. This results in > absence of dmesg file but will still have files relating to other parititons. > > > --- > > Aruna Balakrishnaiah (3): > Retreive header size from pstore. > powerpc/pseries: Re-organise the oops compression code > powerpc/pseries: Support compression of oops text via pstore > > > arch/powerpc/platforms/pseries/nvram.c | 236 +++++++++++++++++++++++--------- > fs/pstore/platform.c | 7 + > include/linux/pstore.h | 6 + > 3 files changed, 182 insertions(+), 67 deletions(-) >