2. Watermark Working In Linux
Detriment:
•Statically defined.
•Almost, whole memory needs to be filled to start reclamation.
•Could cause I/O pressure.
•Reclamation could cause false positives, leading to thrashing.
• Trigger’s page replacement.
• Defines aggression of the
replacement policy.
• Are per zone free list's waypoint.
• Represented as count of free
pages.
3. Swappiness variable in Linux scan rate
• Detriment:
❑Ambiguity in semantics of variable.
❑Global variable that effects the whole node.
4. OOM in Linux
• Kills the process with highest
OOM badness.
• Detriment:
❑oom_score_adj :
❑Admin or system developer has little
or no clue on tuning this variable per
process.
❑Might kill a process that’s of
importance to system.
❑Does not provide right statistics for
developer’s debugging.
5. RMAP [Reverse Mapping]
• Opposite to Memory Mapping.
• Traverses the PTE of a page and cumulates hardware
reference count.
