[yocto] Using tmpfs for WORKDIR

[Burton, Ross]

Hi Martin,

On 13 August 2013 12:32, Martin Jansa <martin.jansa at gmail.com> wrote:
> 1) with 64GB ram + rm_work I can do my huge world builds (with 20+ layers)
> in tmpfs (whole TMPDIR not only WORKDIR)

As I said, ungodly amounts. ;)

I expect tmpfs for $WORKDIR or $TMPDIR is incredibly useful to remove
I/O limits from CPU-heavy systems.  I've only a i7 but I expect you've
got quite a bit more CPU available for builds.

> 4) using tmpfs has 2 more advantages
>    - disks don't wear off so fast

Definitely.  I had a paragraph along these lines in my drafts but
deleted it.  Even with just WORKDIR in tmpfs I was seeing massively
reduced disk use as it was only used to read the source tarball from
downloads, reading the sysroot (likely entirely cached), and writing
the results to sysroot/sstate/deploy.

Ross