Paper work updates

1. page block's used percentage tracking kernel thread

• in-use pages percentage in page block.
• debug option
  • echo 1 > /proc/son/debug
• can be on/off by procfs
  • echo 1 > /proc/son/scan_pbstate_enable
• log
  • son/son_proc.c son_scan.c
  • fs/proc/internal.h

2. reference counting kernel thread

• per-page reference counting.
• debug option
  • echo 1 > /proc/son/debug
• can be on/off by procfs
  • echo 1 > /proc/son/scan_refcount_enable
• log
  • son/son_proc.c son_scan.c
  • include/linux/mm_types.h mmzone.h page_idle.h
  • include/son/son.h
  • kernel/fork.c
  • mm/memory.c page_alloc.c

3. obtained free paage block during compaction.

• obtained page block during sysfs memory compaction.
• output in ftrace ring buffer
• log
  • mm/internal.h migrate.c compaction.c

4. page block utilization information.

• log page block utilization in radix tree node.
• isolate page block which contains unmovable pages from compaction target.
• linked list per page block utilization(BLUE, GREEN, YELLOW, RED)
• log
  • include/linux/mm_types.h mmzone.h
  • include/son/son.h
  • son/son_scan.c
  • mm/memory.c
  • mm/page_alloc.c

5. page block utilization monitoring by proc.

• monitor page block utilizatino by color type in user space.
• used seq_file interface similar to unusable free space index interface in sysfs.
• can be seen by procfs
  • cat /proc/son/pbstat_info_show
  • cat /proc/son/pbstat_info_show_raw (to plot graph)
• log
  • include/son/son.h
  • son/son_proc.c

6. TODO

• make kcompactd to act before DC.
• make kcompactd compaction algorithm to use page block utilize information.
• make threshold vale similar to WMARK value.

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