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. As I said before, when I have portage's work directory on disk, I see the drive light blinking like crazy so it is doing something, reading or writing. When portage's work directory is on tmpfs, it only blinks when I first start the process which should be unpacking the tarball and then at the end when it is installing the package. In between that, it is just the normal stuff of my wallpaper changing or it checking my emails. So, it may store something in ram as it does in both cases but it is also storing things on the drive or else the light would not be blinking so much. I'm not real big on rebooting but you and Neil are about to make me test this and reboot between each and every test. If nothing else, just to show that drop_caches does the same as rebooting like kernel.org says, except for the programs are still actually running. Dale :-) :-) -- I am only responsible for what I said ... Not for what you understood or how you interpreted my words!
