In defense of swap [in Linux]: common misconceptions

Note trans. : This fascinating article, revealing in detail the purpose of swap in Linux and responding to a common misconception about it, was written by Chris Down - SRE from Facebook, who, in particular, is developing new metrics in the kernel that help analyze the load on the RAM. And he begins his story with a concise TL; DR ...

TL; DR

• Swap is a fairly important part of a well-functioning system. Without it, it is more difficult to achieve reasonable memory management.
• Swap is needed not so much for urgent memory acquisition, but for even and efficient memory release. To use it as an “urgent memory” is generally very harmful.
• Disabling swap does not save you from disk I / O problems with memory contention — disk I / O simply moves from anonymous pages to file pages. Not only can this be less effective, since there remains a smaller pool of pages available for release, but in itself can contribute to the emergence of this high competition.

Foreword

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