In virtual memory management, what does the term “page stealing” describe?

Introduction / Context:
Operating systems using demand paging must allocate limited physical frames among processes. When memory pressure rises, the kernel may reassign frames to keep the system responsive. Understanding page stealing helps diagnose thrashing, tune workloads, and interpret performance counters.

Given Data / Assumptions:

• Multiple processes each have a working set (the set of pages they are actively using).
• Physical memory is finite, and the OS can reallocate frames between processes.
• We focus on the definition, not the desirability, of the behavior.

Concept / Approach:

Page stealing occurs when the OS removes page frames from one process's working set to supply another process, typically under memory pressure. This can temporarily reduce the victim's performance if the stolen pages are soon needed again, and may signal inadequate RAM or suboptimal workload mix.

Step-by-Step Solution:

Verification / Alternative check:

OS texts and performance guides document working set trimming and page stealing mechanisms in Windows, Unix-like systems, and VM hypervisors.

Why Other Options Are Wrong:

• sign of an efficient system: not necessarily; it often indicates pressure.
• tuning goal: minimizing unnecessary stealing is the goal, not maximizing it.
• taking larger disk spaces: concerns swap sizing, not stealing frames.

Common Pitfalls:

• Confusing swapping capacity with frame allocation policies.

Final Answer:

is taking page frames from other working sets.