Info on possible misheap
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3fd4fd98 1<h2>Swapcache</h2>
3<p>DragonFly BSD has numerous performance advantages over most other operating systems. One of the novel features in DragonFly that is able to boost the throughput of a large number of workloads is called swapcache. Swapcache gives the kernel the ability to retire cached pages to one or more interleaved swap devices, usually using commodity solid state disks. By caching filesystem metadata, data or both on an SSD the performance of many read-centric workloads is improved and worst case performance is kept well bounded.</p>
5<p>The following chart depicts relative performance of a system with and without swapcache. The application being tested is a PostgreSQL database under a read-only workload, with varying database sizes ranging from smaller than the total ram in the system to double the size of total available memory.</p>
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c0683b48 7[[!template id=performance-swapcache.tmpl]]
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290c40c9 9<p>(figure above uses SVG, if your browser doesn't show anything plugin needs to be installed (or use other browser))<p>
3fd4fd98 10<p>As you can plainly see, performance with swapcache is more than just well bounded, it is dramatically improved. Similar gains can be seen in many other scenarios.</p>