From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luck, Tony" Subject: Re: [RFC] persistent store (version 2) (part 1 of 2) Date: Wed, 01 Dec 2010 10:01:19 -0800 Message-ID: <4cf68d6f178373258a@agluck-desktop.sc.intel.com> References: <20101201005851.GA31571@kroah.com> Return-path: Received: from mga11.intel.com ([192.55.52.93]:5574 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755691Ab0LASBT (ORCPT ); Wed, 1 Dec 2010 13:01:19 -0500 In-reply-to: <20101201005851.GA31571@kroah.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: greg@kroah.com, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Cc: tglx@linutronix.de, mingo@elte.hu, akpm@linux-foundation.org, ying.huang@intel.com, Borislav Petkov , David Miller , Alan Cox , Jim Keniston , Kyungmin Park , Geert Uytterhoeven > As you are adding new sysfs files, you are required to document them in > Documentation/ABI/ as well. Is this what you need? -Tony --- diff --git a/Documentation/ABI/testing/sysfs-pstore b/Documentation/ABI/testing/sysfs-pstore new file mode 100644 index 0000000..083fcf7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-pstore @@ -0,0 +1,35 @@ +Where: /sys/firmware/pstore/... +Date: January 2011 +Kernel Version: 2.6.38 +Contact: tony.luck@intel.com +Description: Generic interface to platform dependent persistent storage. + + Platforms that provide a mechanism to preserve some data + across system reboots can register with this driver to + provide a generic interface to show records captured in + the dying moments. In the case of a panic() the last part + of the console log is captured, but other interesting + data can also be saved. + + $ ls -l /sys/firmware/pstore + total 0 + -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-1 + --w------- 1 root root 0 Nov 30 15:38 erase + + Different users of this interface will result in different + filename prefixes. Currently two are defined: + + "dmesg" - saved console log + "mce" - architecture dependent data from fatal h/w error + + The "erase" file is used to signal that a file has been + read and that the underlying platform driver can reclaim + the space in the persistent store. Just write the name of + the file to be removed to the "erase" file: + + $ echo dmesg-1 > /sys/firmware/pstore/erase + + The expectation is that all files in /sys/firmware/pstore + will be saved elsewhere and erased from persistent store + soon after boot to free up space ready for the next + catastrophe.