> The author never explained why putting rarely used pages in swap will improve performance if I have adequate RAM. Putting rarely used (or never to be used ag

> The author never explained why putting rarely used pages in swap will improve performance if I have adequate RAM. Putting rarely used (or never to be used again) pages in swap frees up physical RAM to be used as disk cache, which can improve performance for file access. If you have enough RAM to cover all application memory, and cache your entire filesystem, there is no gain to be had. I agree that slowing down low memory scenarios is silly though. In many cases killing a process is easier to deal with than unexpected poor performance. The slow death of out of memory systems doesn't seem to be unique to having a swapfile though; Linux seems to discard any recoverable pages (such as application / library code backed by files on disc) in the run-up to OOM, resulting in thrashing. Ideally I'd want to have swap, but automatically kill processes when performance deteriorates due to swapping, rather than when the system is strictly out of memory.