1What: /sys/kernel/debug/powerpc/memtrace 2Date: Aug 2017 3KernelVersion: 4.14 4Contact: [email protected] 5Description: This folder contains the relevant debugfs files for the 6 hardware trace macro to use. CONFIG_PPC64_HARDWARE_TRACING 7 must be set. 8 9What: /sys/kernel/debug/powerpc/memtrace/enable 10Date: Aug 2017 11KernelVersion: 4.14 12Contact: [email protected] 13Description: Write an integer containing the size in bytes of the memory 14 you want removed from each NUMA node to this file - it must be 15 aligned to the memblock size. This amount of RAM will be removed 16 from the kernel mappings and the following debugfs files will be 17 created. This can only be successfully done once per boot. Once 18 memory is successfully removed from each node, the following 19 files are created. 20 21What: /sys/kernel/debug/powerpc/memtrace/<node-id> 22Date: Aug 2017 23KernelVersion: 4.14 24Contact: [email protected] 25Description: This directory contains information about the removed memory 26 from the specific NUMA node. 27 28What: /sys/kernel/debug/powerpc/memtrace/<node-id>/size 29Date: Aug 2017 30KernelVersion: 4.14 31Contact: [email protected] 32Description: This contains the size of the memory removed from the node. 33 34What: /sys/kernel/debug/powerpc/memtrace/<node-id>/start 35Date: Aug 2017 36KernelVersion: 4.14 37Contact: [email protected] 38Description: This contains the start address of the removed memory. 39 40What: /sys/kernel/debug/powerpc/memtrace/<node-id>/trace 41Date: Aug 2017 42KernelVersion: 4.14 43Contact: [email protected] 44Description: This is where the hardware trace macro will output the trace 45 it generates. 46