Chapter 18 : Page Reclaim and Swapping¶

18.1 Overview¶

Swappable Pages¶

Page Thrashing¶

Page-Swapping Algorithms¶

18.2 Page Reclaim and Swapping in the Linux Kernel¶

Organization of the Swap Area¶

Checking Memory Utilization¶

Selecting Pages to Be Swapped Out¶

Handling Page Faults¶

Shrinking Kernel Caches¶

18.3 Managing Swap Areas¶

Data Structures¶

Creating a Swap Area¶

Activating a Swap Area¶

18.4 The Swap Cache¶

Identifying Swapped-Out Pages¶

Structure of the Cache¶

Adding New Pages¶

Searching for a Page¶

18.5 Writing Data Back¶

18.6 Page Reclaim¶

Overview¶

Data Structures¶

Determining Page Activity¶

Shrinking Zones¶

Isolating LRU Pages and Lumpy Reclaim¶

Shrinking the List of Active Pages¶

Reclaiming Inactive Pages¶

18.7 The Swap Token¶

18.8 Handling Swap-Page Faults¶

Swapping Pages in¶

Reading the Data¶

Swap Readahead¶

18.9 Initiating Memory Reclaim¶

Periodic Reclaim with kswapd¶

Swap-out in the Event of Acute Memory Shortage¶

18.10 Shrinking Other Caches¶

Data Structures¶

Registering and Removing Shrinkers¶

Shrinking Caches¶

Summary¶

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