On Wed, Jun 04, 2014 at 03:02:02PM -0400, Andev wrote:
On Wed, Jun 4, 2014 at 2:33 PM, Andev <debiandev@gmail.com> wrote:
On Wed, Jun 4, 2014 at 1:56 PM, <Valdis.Kletnieks@vt.edu> wrote:
The trick to remember is that you probably don't want to use the ramdisk as the permanent host, so...
1) Setup your git tree on permanent storage 2) Set up your ramdisk 3) cd /my/source/tree 4) tar -c --exclude=.git -f - . | (cd /mnt/ramdisk && tar -xvf -)
then cd /mnt/ramdisk and start building. Remember if you make changes to copy them back to /my/source/tree :)
(The --exclude=.git will avoid copying about 900M onto the ramdisk. Skip that if you need the git history on the ramdisk for doing a bisect or similar)
Thanks Valdis for the instructions.
So I tried the following to mount a tmpfs
$ sudo mount -t tmpfs -o size=2000m tmpfs ./ramlinux/ $ tar -c --exclude=.git -f - . | (cd ~/ramlinux && tar -xvf -)
And it works fine. I am not sure if tmpfs has any advantages over ramdisk.
So I might have jumped the bullet on saying that it works fine. I see no difference between the compilation speed on native disk vs tmpfs.
Then perhaps disk I/O is not your limiting factor, but compute power is.
For a defconfig this is the time I get:
real 6m35.407s user 10m3.734s sys 1m0.514s
I don't know your hardware setup, but that seems a bit slow, are you building with all processors "full"? You should always add -j NUMBER" to your kernel make command, where NUMBER is 2x the number of CPUs you have in the box. Good luck, greg k-h