From ca01d6dd2d7a2652000307520777538740efc286 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Tue, 28 Dec 2010 14:25:21 -0800 Subject: pstore: new filesystem interface to platform persistent storage Some platforms have a small amount of non-volatile storage that can be used to store information useful to diagnose the cause of a system crash. This is the generic part of a file system interface that presents information from the crash as a series of files in /dev/pstore. Once the information has been seen, the underlying storage is freed by deleting the files. Signed-off-by: Tony Luck --- Documentation/ABI/testing/pstore | 35 +++++++++++++++++++++++++++++++ Documentation/ABI/testing/sysfs-fs-pstore | 7 +++++++ 2 files changed, 42 insertions(+) create mode 100644 Documentation/ABI/testing/pstore create mode 100644 Documentation/ABI/testing/sysfs-fs-pstore (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/pstore b/Documentation/ABI/testing/pstore new file mode 100644 index 000000000000..f1fb2a004264 --- /dev/null +++ b/Documentation/ABI/testing/pstore @@ -0,0 +1,35 @@ +Where: /dev/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. + + # mount -t pstore - /dev/pstore + + $ ls -l /dev/pstore + total 0 + -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1 + + 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 + + Once the information in a file has been read, removing + the file will signal to the underlying persistent storage + device that it can reclaim the space for later re-use. + + $ rm /dev/pstore/dmesg-erst-1 + + The expectation is that all files in /dev/pstore + will be saved elsewhere and erased from persistent store + soon after boot to free up space ready for the next + catastrophe. diff --git a/Documentation/ABI/testing/sysfs-fs-pstore b/Documentation/ABI/testing/sysfs-fs-pstore new file mode 100644 index 000000000000..8e659d854805 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-fs-pstore @@ -0,0 +1,7 @@ +What: /sys/fs/pstore/kmsg_bytes +Date: January 2011 +Kernel Version: 2.6.38 +Contact: "Tony Luck" +Description: + Controls amount of console log that will be saved + to persistent store on oops/panic. -- cgit v1.2.3