> A new tmpfs-like FS that stores all files in RAM at first, stores them on disk if they grow large and also on disk if they remain for a long time.
You are aware that Linux, like all modern operating system kernels, has a unified caching subsystem, right? The VM subsystem _already does_ exactly what you want: it will page out tmpfs pages to backing storage (in this case, swap) just as it would page out file-backed pages to their backing stores; the exact identity of the backing store doesn't make a difference. The distinction between bytes in memory and bytes on disk isn't nearly as clear-cut as you think.
Posted Jun 4, 2012 5:08 UTC (Mon) by raven667 (subscriber, #5198)
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One of the few reasonable statements in this discussion... Using the robust features of the kernel to implement the most sensible policy, who would have thought.