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-rw-r--r--Documentation/ABI/testing/ppc-memtrace45
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+What: /sys/kernel/debug/powerpc/memtrace
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: This folder contains the relevant debugfs files for the
+ hardware trace macro to use. CONFIG_PPC64_HARDWARE_TRACING
+ must be set.
+
+What: /sys/kernel/debug/powerpc/memtrace/enable
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: Write an integer containing the size in bytes of the memory
+ you want removed from each NUMA node to this file - it must be
+ aligned to the memblock size. This amount of RAM will be removed
+ from the kernel mappings and the following debugfs files will be
+ created. This can only be successfully done once per boot. Once
+ memory is successfully removed from each node, the following
+ files are created.
+
+What: /sys/kernel/debug/powerpc/memtrace/<node-id>
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: This directory contains information about the removed memory
+ from the specific NUMA node.
+
+What: /sys/kernel/debug/powerpc/memtrace/<node-id>/size
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: This contains the size of the memory removed from the node.
+
+What: /sys/kernel/debug/powerpc/memtrace/<node-id>/start
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: This contains the start address of the removed memory.
+
+What: /sys/kernel/debug/powerpc/memtrace/<node-id>/trace
+Date: Aug 2017
+KernelVersion: 4.14
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: This is where the hardware trace macro will output the trace
+ it generates.