On Thu, Sep 6, 2012 at 10:20 AM, Dale <[email protected]> wrote: > Nicolas Sebrecht wrote: >> The 06/09/12, Dale wrote: >> >>> Not quite. The theory is that if you put portages work directory on >>> tmpfs, then all the writes and such are done in ram which is faster. >> No! This is too much simplistic view to explain what you see. >> >> In practice, _all_ the writes always happen in RAM whatever backend >> storage you use. >> >> The difference you could see is if there is not enough RAM for the >> kernel cache, it will have to wait for the backend storage. >> > > > OK. Step by step here so hopefully you and Neil can follow. > > Freshly booted system. > Clear caches just to be sure > > emerge foo with portages work directory on tmpfs > clear caches again > emerge foo with portages work directory on disk > clear caches again. > emerge foo with portages work directory on tmpfs > clear caches again > emerge foo with portages work directory on disk > > You repeat this enough times and you see that it doesn't matter if > portage's work directory is on disk or on tmpfs.
If you have enough RAM, then this is certainly true. Nobody is disputing that. They've been trying to explain that there's a difference when you _don't_ have that much RAM, and they've been trying to explain the mechanism behind that. -- :wq
