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 each NUMA node in the kernel mappings and the following debugfs files will be created. Once memory is successfully removed from each node, the following files are created. To re-add memory to the kernel, echo 0 into this file (it will be automatically onlined). What: /sys/kernel/debug/powerpc/memtrace/ 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//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//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//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.