Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/pstore b/Documentation/ABI/testing/pstore
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+Where:		/sys/fs/pstore/... (or /dev/pstore/...)
+Date:		March 2011
+Kernel Version: 2.6.39
+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 -o kmsg_bytes=8000 - /sys/fs/pstore
+
+		$ ls -l /sys/fs/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 /sys/fs/pstore/dmesg-erst-1
+
+		The expectation is that all files in /sys/fs/pstore/
+		will be saved elsewhere and erased from persistent store
+		soon after boot to free up space ready for the next
+		catastrophe.
+
+		The 'kmsg_bytes' mount option changes the target amount of
+		data saved on each oops/panic. Pstore saves (possibly
+		multiple) files based on the record size of the underlying
+		persistent storage until at least this amount is reached.
+		Default is 10 Kbytes.
+
+		Pstore only supports one backend at a time. If multiple
+		backends are available, the preferred backend may be
+		set by passing the pstore.backend= argument to the kernel at
+		boot time.
+