Nicolas Sebrecht wrote: > The 05/09/12, Dale wrote: >> Michael Mol wrote: >>> On Wed, Sep 5, 2012 at 11:17 AM, Neil Bothwick <n...@digimed.co.uk> wrote: >>>> On Wed, 05 Sep 2012 07:52:45 -0500, Dale wrote: >>>> >>>>>>> I might also add, I see no speed improvements in putting portages >>>>>>> work directory on tmpfs. I have tested this a few times and the >>>>>>> difference in compile times is just not there. >>>>>> Probably because with 16GB everything stays cached anyway. >>>>> I cleared the cache between the compiles. This is the command I use: >>>>> >>>>> echo 3 > /proc/sys/vm/drop_caches >>>> But you are still using the RAM as disk cache during the emerge, the data >>>> doesn't stay around long enough to need to get written to disk with so >>>> much RAM for cache. >>> Indeed. Try setting the mount to write-through to see the difference. >>> >>> >> When I run that command, it clears all the cache. It is the same as if >> I rebooted. Certainly you are not thinking that cache survives a reboot? > You missed the point. One of the first thing emerge will do is to > uncompress the package. At this time, all the files are cached in RAM. > Hence, everything needed for the build/compilation will come from the > cache like it would do with tmpfs. >
You miss this point not me. I *cleared* that cache. From kernel.org: drop_caches Writing to this will cause the kernel to drop clean caches, dentries and inodes from memory, causing that memory to become free. To free pagecache: echo 1 > /proc/sys/vm/drop_caches To free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches To free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches I can confirm this is done with free, top or htop. See my reply to Neil for more on this. Dale :-) :-) -- I am only responsible for what I said ... Not for what you understood or how you interpreted my words!