i actually very much doubt that they can do better. writing any sort of large LRU cache in a machine with swap turned on is a bad idea because a lot of your ca

i actually very much doubt that they can do better. writing any sort of large LRU cache in a machine with swap turned on is a bad idea because a lot of your cache will get swapped out and then swapped back in unnecessarily when you try to use that memory for something else. mlock can be used to mitigate this effect but the default mlock limit is so low that it's useless in practice. another thing to consider is that using mmap gives you a big advantage over writing your own disk cache because the OS can take advantage of the paging hardware in the processor, which you can't do from userspace.